JP6850246B2 - Optical signal buffer memory circuit and optical signal buffer method - Google Patents

Description

The present invention relates to an optical signal buffer memory circuit and an optical signal buffer method in optical communication, optical processing, and an optical computer.

The following methods have been proposed as typical methods for realizing an optical signal buffer.

[First prior art]
In the first method, as shown in FIG. 18, a plurality of optical waveguides for optical delay ODL-1 to ODL-N having different lengths are prepared, and these optical waveguides for optical delay ODL-1 to ODL-N are prepared. An optical switch OS-1 is arranged at the input end of the light, and an optical waveguide OC-1 is arranged at the output end, and an optical signal input from the input port P-OP-In is used as a propagation path for light using the optical switch OS-1. By switching the optical waveguide ODL-1 to ODL-N for delay, a desired optical delay is given and the function as a buffer memory is realized by outputting from the output port P-OP-Out.

In this first method, delays other than the optical waveguides ODL-1 to ODL-N for optical delay prepared in advance cannot be applied, and realistic optical propagation that can be switched by the optical switch OS-1 can be applied. Since the number of paths is limited (there are dozens of commercial products at present, and there is another problem that the insertion optical loss increases as the number of switches is increased), the optical data signal sequence Only an extremely limited optical buffer memory can be realized with respect to the storage time, and as the number of patterns of the amount of optical delay that can be switched increases, the optical circuit becomes larger.

[Second prior art]
The second method uses an optical circuit as shown in FIG. 19 to input a stored optical data signal sequence from the input port P-OP-In in the fiber loop or the optical waveguide loop O-Loop. The desired optical delay is achieved by rotating the optical amplifier OA while compensating for propagation loss, extracting it as an optical data signal string at a desired timing by the optical switch OS-2, and outputting it from the output port P-OP-Out. Is given to realize the function as an optical buffer memory.

This method was devised with the expectation that it could overcome the problem of the first method, "As the number of patterns of switchable optical delay increases, the optical circuit becomes larger." However, in this second method, as the number of orbits of the optical data signal sequence increases, the optical amplifier for compensating for the propagation loss of the optical waveguide loop O-Loop for orbiting the optical data signal train. The optical waveform of the optical data signal sequence gradually collapses due to the influence of mixed noise such as ASE (Amplified Spontaneous Emission) from OA and the influence of the dispersion effect of the optical waveguide loop O-Loop, and the number of laps is at least about 100 times. It is known that it is difficult to maintain a data signal longer than that (see Non-Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-174300

R. Langenhorst et al, "Fiber Loop Optical Buffer," JOURNAL OF LIGHT WAVE TECHNOLOGY, IEEE, 1996, VOL. 14, NO.3, pp. 324-335 Q. Lai, et al., “Low-Power Compact 2x2 Thermooptic Silica-on-Silicon Waveguide Switch with Fast Response”, IEEE PHOTONICS TECHNOLOGY LETTERS, MAY 1998, VOL. 10, NO.5, pp. 681-683 S. Diez, et al., “160Gbit / s all-optical demultiplexer using hybrid gain-transparent SOA Mach-Zehnder interferometer”, ELECTRONICS LETTERS, 17 AUGUST 2000, Vol. 36, No. 17, pp. 1484-1486 T. Ito, et al., "Bit-rate and format conversion from 10-Gbit / s WDM channels to a 40-Gbit / s channel using a monolithic Sagnac interferometer integrated with parallel-amplifier structure," IEE Proc.-Optoelectron. , February 2004, Vol. 151, No. 1, pp. 41-45 H. Nakamura, et al., "Ultra-fast photonic crystal / quantum dot all-optical switch for future photonic networks," Optics Express, 2004, Vol. 12, No. 26, pp. 6606-6614

An object of the present invention is to give an arbitrary integral multiple of the optical signal length to be output in optical communication, optical processing, an optical signal buffer memory circuit in an optical computer, and an optical signal buffer method. It is possible, and unlike the optical buffer memory described in the [first prior art], "the more patterns of adjustable optical delay amount, the larger the optical circuit becomes". In addition, as in the optical buffer memory described in the [second prior art], "the influence of mixed noise such as ASE from the loss compensation optical amplifier used in the optical buffer memory circuit and the influence of mixed noise in the optical buffer memory circuit" An optical delay limit that can be applied due to deterioration of the optical signal waveform due to the influence of the dispersion effect associated with optical waveguide is generated. ”In principle, an infinite amount of optical delay can be applied. It is to provide a signal buffer memory circuit and an optical signal buffer method.

That is, an object of the present invention is to provide an optical signal buffer memory circuit and an optical signal buffer method capable of imparting an infinite amount of optical delay without causing waveform deterioration with a simple configuration.

Further, the present inventors have previously proposed an optical signal buffer memory circuit and an optical signal buffer method for realizing the optical signal buffer shown in FIG. 20 (see Patent Document 1), but the present invention is different from Patent Document 1. It is an object of the present invention to provide an optical signal buffer memory circuit and an optical signal buffer method that realize a reset operation in an optical data buffer memory by different circuits and methods. Since the optical signal buffer memory circuit shown in FIG. 20 has a configuration common to that of the present invention, the configuration will be described in the present invention.

The optical signal buffer memory circuit according to the first invention that solves the above problems is
In an optical signal buffer memory circuit that holds a data pattern in the circuit
The external optical input port P-OCLK-In-0 for inputting the optical clock pulse train CLK-0 output from the clock signal light source and the erasing control for erasing the data pattern held in the circuit. The optical clock pulse train CLK-0 is output or the optical clock pulse train is output as the external optical input port P-ERS-In-0 for inputting the optical signal pulse train ERS-1 and the secondary optical clock pulse train CLK-1. An optical control type optical intensity switch OSW-01 having an optical output port P-OSW-01-Out that cuts and outputs the output of CLK-0, and
An optical waveguide 53 that guides the secondary optical clock pulse train CLK-1 output from the optical output port P-OSW-01-Out, and
An optical input port P-OCLK-In connected to the optical waveguide 53 to input the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out, and the optical input port. Optical output port P- located on the bar side with respect to P-OCLK-In
It is located on the optical waveguide of two first optical interference arms having MZ-1-bar and an optical output port P-MZ-1-cross located on the cross side, and one of the first optical interference arms. The optical phase modulation means L1-1 for modulating the phase of the optical signal pulse train propagating in the first optical interference arm and the other optical waveguide of the first optical interference arm are located on the optical waveguide. Mach-Zenda interference-type light intensity that has an optical phase modulation means R1-1 for modulating the phase of the optical signal pulse train propagating in the first optical interference arm and functions as a Mach-Zenda-type interferer. Modulation means MZ-1 and
An optical waveguide 18 that is connected to an external optical input port P-Data-In for inputting an optical signal pulse train Data-1 having information on the data pattern and guides the optical signal pulse train Data-1.
An optical input port PC1-1 connected to the optical waveguide 18 to which the optical signal pulse train Data-1 from the external optical input port P-Data-In is input, and an optical output port P-MZ-1- Optical input ports PC1-2 and optical output ports PC1-3 and PC1-4 to which optical signal pulse trains from either bar or the optical output port P-MZ-1-cross are input. Optical branch for branching and outputting the optical signal pulse train input from the optical input ports P-C1-2 and P-C1-1 to the optical output ports P-C1-3 and P-C1-4. Part C-1 and
An optical waveguide 14 that guides an optical signal pulse train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-C1-2.
Light from the optical output port PC1-3 connected to the optical input port PL1-1 for inputting the optical signal pulse train for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L that guides a signal pulse train and
Light from the optical output port PC1-4 connected to the optical input port P-R1-1 for inputting the optical signal pulse train for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R that guides a signal pulse train,
Optical signal pulse trains provided on the optical waveguide 15L or the optical waveguide 15R and simultaneously output from the optical output ports P-C1-3 and P-C1-4 are the optical input ports P-L1-1 and P-. An optical waveguide portion D-D-1 that produces an optical delay for adjusting the timing of reaching R1-1 so as to be equal to or greater than the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period.
With
As the optical clock pulse train CLK-0, an RZ (Return to Zero) type optical signal pulse train continues to be input from the external optical input port P-OCLK-In-0.
The optical signal pulse train ERS-1 is synchronized with the clock of the optical clock pulse train CLK-0, synchronized with the period of the data pattern, and has the same length as the data length of the data pattern. Signal pulse train
After holding the data pattern in the circuit, when the optical signal pulse train ERS-1 is input from the external optical input port P-ERS-In-0, the data length of the optical signal pulse train ERS-1 is reached. However, the output of the optical clock pulse train CLK-0 is cut to obtain the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out to the optical input port P-OCLK-In. Output and
In the Mach-Zender interference type optical intensity modulation means MZ-1, the optical output port P is provided by the secondary optical clock pulse train CLK-1 which is input from the optical input port P-OCLK-In and whose output is cut. It is characterized in that a state in which an optical signal pulse train is not output from -MZ-1-bar and P-MZ-1-cross is created, the holding state of the data pattern is canceled, and the state is returned to the initial state.

The optical signal buffer memory circuit according to the second invention that solves the above problems is
In the optical signal buffer memory circuit according to the first invention.
The light control type light intensity switch OSW-01 is
It is located on the external optical input port P-OCLK-In-0 and the optical output ports P-MZ-0-bar and cross side located on the bar side with respect to the external optical input port P-OCLK-In-0. It is located on the optical waveguide of two second optical interference arms having an optical output port P-MZ-0-cross and one of the second optical interference arms, and propagates in the second optical interference arm. An optical phase modulation means L0 for modulating the phase of the optical signal pulse train, and an optical signal pulse train located on the optical waveguide of the other second optical interference arm and propagating in the second optical interference arm. Mach-Zenda interference-type light intensity modulation means MZ-0, which has an optical phase-modulating means R0 for imparting modulation to the phase of the light, and functions as a Mach-Zender-type interferator.
An optical waveguide 55 that guides the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0, and
Optical input port PC0-1 and optical output port PC0-3 connected to the optical waveguide 55 to which the optical signal pulse train ERS-1 from the external optical input port P-ERS-In-0 is input. , P-C0-4, and the optical signal pulse train ERS-1 input from the optical input port P-C0-1 is branched and output to the optical output ports P-C0-3 and P-C0-4. Optical branch C-0 to make it
An optical signal pulse train from the optical output port PC0-3 connected to an optical input port P-L0-1 for inputting an optical signal pulse train for inducing an optical phase modulation action to the optical phase modulation means L0. Optical waveguide 54L that guides
An optical signal pulse train from the optical output port PC0-4 connected to an optical input port P-R0-1 for inputting an optical signal pulse train for inducing an optical phase modulation action to the optical phase modulation means R0. Optical waveguide 54R that guides
Optical signal pulse trains provided on the optical waveguide 54L or the optical waveguide 54R and simultaneously output from the optical output ports P-C0-3 and P-C0-4 are the optical input ports P-L0-1 and P-. An optical waveguide portion DD-0 that produces an optical delay for adjusting the timing of reaching R0-1 so as to be equal to or greater than the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period.
With
Either the optical output port P-MZ-0-bar or the optical output port P-MZ-0-clock is set as the optical output port P-OSW-01-Out, and the optical signal pulse train ERS-1 is input. When not, the optical clock pulse train CLK-0 is output as the secondary optical clock pulse train CLK-1, and when the optical signal pulse train ERS-1 is input, the data length of the optical signal pulse train ERS-1 is increased. It is characterized in that the output of the optical clock pulse train CLK-0 is cut for a short time and output as the secondary optical clock pulse train CLK-1.

The optical signal buffer memory circuit according to the third invention that solves the above problems is
In the optical signal buffer memory circuit according to the second invention.
When the optical signal pulse train ERS-1 is input from the external optical input port P-ERS-In-0, the input optical signal pulse train ERS-1 is used to drive the optical phase modulation means R0 and L0. Then, the phase of the optical clock pulse train CLK-0 propagating in the two second optical interference arms of the Mach-Zender interference type light intensity modulation means MZ-0 is π-modulated to π-modulate the optical signal pulse train. The output of the optical clock pulse train CLK-0 is cut only during the data length of the ERS-1 to obtain the secondary optical clock pulse train CLK-1, which is the light from the optical output port P-OSW-01-Out. It is characterized by outputting to the input port P-OCLK-In.

The optical signal buffer memory circuit according to the fourth invention that solves the above problems is
In the optical signal buffer memory circuit according to the first invention.
The light control type light intensity switch OSW-01 is
The optical is composed of a flat substrate circuit type multi-mode optical waveguide that interferes with the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1, and the light is input only during the data length of the optical signal pulse train ERS-1. A multi-mode optical waveguide WG-M that removes the optical clock pulse train from the clock pulse train CLK-0 and outputs it as the secondary optical clock pulse train CLK-1.
A flat substrate circuit type single-mode optical waveguide WG-S for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the multi-mode optical waveguide WG-M. -In-01 and
A flat substrate circuit type single-mode optical waveguide WG-S for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the multi-mode optical waveguide WG-M. −In-02 and
A flat substrate circuit type single-mode optical waveguide WG-S- for guiding the secondary optical clock pulse train CLK-1 from the multi-mode optical waveguide WG-M to the optical output port P-OSW-01-Out. Out-01 and
It is characterized by having.

The optical signal buffer memory circuit according to the fifth invention that solves the above problems is
In the optical signal buffer memory circuit according to the fourth invention.
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-01 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
A flat substrate circuit type single-mode optical beam for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type phase modulator WG-Ph-01. Waveguide WG-S-In-03 and
With
The single-mode optical waveguide WG-S-In-02 guides the optical signal pulse train ERS-1 whose phase has been adjusted in the optical waveguide type phase modulator WG-Ph-01 to the multi-mode optical waveguide WG-M. It is characterized by waves.

The optical signal buffer memory circuit according to the sixth invention for solving the above problems is
In the optical signal buffer memory circuit according to the fourth invention.
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-02 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
A flat board circuit type single-mode optical beam for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type phase modulator WG-Ph-02. Waveguide WG-S-In-04 and
With
The single-mode optical waveguide WG-S-In-01 guides the phase-adjusted optical clock pulse train CLK-0 in the optical waveguide type phase modulator WG-Ph-02 to the multi-mode optical waveguide WG-M. It is characterized by waves.

The optical signal buffer memory circuit according to the seventh invention that solves the above problems is
In the optical signal buffer memory circuit according to the fourth invention.
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-01 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
An optical waveguide type intensity attenuation unit WG-Att-01 for adjusting the relative optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 by attenuating the optical signal pulse train ERS-1.
A flat substrate circuit type single-mode optical beam for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type intensity attenuation unit WG-Att-01. Waveguide WG-S-In-03 and
Flat substrate circuit type single-mode optical waveguide WG-S-In-05 for waveguideing between the optical waveguide type intensity attenuation unit WG-Att-01 and the optical waveguide type phase modulation unit WG-Ph-01. When,
With
The single-mode optical waveguide WG-S-In-02 guides the optical signal pulse train ERS-1 whose phase has been adjusted in the optical waveguide type phase modulator WG-Ph-01 to the multi-mode optical waveguide WG-M. It is characterized by waves.

The optical signal buffer memory circuit according to the eighth invention that solves the above problems is
In the optical signal buffer memory circuit according to the fourth invention.
The light control type light intensity switch OSW-01 is
An optical waveguide type intensity attenuation unit WG-Att-02 for adjusting the relative optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 by attenuating the optical clock pulse train CLK-0.
A flat board circuit type single-mode optical beam for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type intensity attenuation unit WG-Att-02. Waveguide WG-S-In-04 and
An optical waveguide type phase modulator WG-Ph-01 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
A flat substrate circuit type single-mode optical beam for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type phase modulator WG-Ph-01. Waveguide WG-S-In-03 and
With
The single-mode optical waveguide WG-S-In-01 uses the optical clock pulse train CLK-0 whose light intensity is attenuated and adjusted in the optical waveguide type intensity attenuation unit WG-Att-02, and the multi-mode optical waveguide WG-M. Waveguided to
The single-mode optical waveguide WG-S-In-02 guides the optical signal pulse train ERS-1 whose phase has been adjusted in the optical waveguide type phase modulator WG-Ph-01 to the multi-mode optical waveguide WG-M. It is characterized by waves.

The optical signal buffer memory circuit according to the ninth invention that solves the above problems is
In the optical signal buffer memory circuit according to the fourth invention.
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-02 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
A flat board circuit type single-mode optical beam for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type phase modulator WG-Ph-02. Waveguide WG-S-In-04 and
An optical waveguide type intensity attenuation unit WG-Att-01 for adjusting the relative optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 by attenuating the optical signal pulse train ERS-1.
A flat substrate circuit type single-mode optical beam for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type intensity attenuation unit WG-Att-01. Waveguide WG-S-In-03 and
With
The single-mode optical waveguide WG-S-In-01 guides the phase-adjusted optical clock pulse train CLK-0 in the optical waveguide type phase modulator WG-Ph-02 to the multi-mode optical waveguide WG-M. Wave,
The single-mode optical waveguide WG-S-In-02 uses the optical signal pulse train ERS-1 whose light intensity is attenuated and adjusted in the optical waveguide type intensity attenuation unit WG-Att-01 to the multi-mode optical waveguide WG-M. It is characterized by being guided to.

The optical signal buffer memory circuit according to the tenth invention that solves the above problems is
In the optical signal buffer memory circuit according to the fourth invention.
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-02 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
An optical waveguide type intensity attenuation unit WG-Att-02 for adjusting the relative optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 by attenuating the optical clock pulse train CLK-0.
A flat board circuit type single-mode optical beam for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type intensity attenuation unit WG-Att-02. Waveguide WG-S-In-04 and
Flat substrate circuit type single-mode optical waveguide WG-S-In-06 for waveguideing between the optical waveguide type intensity attenuation unit WG-Att-02 and the optical waveguide type phase modulation unit WG-Ph-02. When,
With
The single-mode optical waveguide WG-S-In-01 guides the phase-adjusted optical clock pulse train CLK-0 in the optical waveguide type phase modulator WG-Ph-02 to the multi-mode optical waveguide WG-M. It is characterized by waves.

The optical signal buffer method according to the eleventh invention for solving the above problems is
As an optical signal buffer memory circuit that holds a data pattern in the circuit
The external optical input port P-OCLK-In-0 for inputting the optical clock pulse train CLK-0 output from the clock signal light source and the erasing control for erasing the data pattern held in the circuit. The optical clock pulse train CLK-0 is output or the optical clock pulse train is output as the external optical input port P-ERS-In-0 for inputting the optical signal pulse train ERS-1 and the secondary optical clock pulse train CLK-1. An optical control type optical intensity switch OSW-01 having an optical output port P-OSW-01-Out that cuts and outputs the output of CLK-0, and
An optical waveguide 53 that guides the secondary optical clock pulse train CLK-1 output from the optical output port P-OSW-01-Out, and
An optical input port P-OCLK-In connected to the optical waveguide 53 to input the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out, and the optical input port. Two first optical interference arms having an optical output port P-MZ-1-bar located on the bar side and an optical output port P-MZ-1-cross located on the cross side with respect to P-OCLK-In. And the optical phase modulation means L1-1 located on the optical waveguide of one of the first optical interference arms and for modulating the phase of the optical signal pulse train propagating in the first optical interference arm. It is located on the optical waveguide of the other first optical interference arm, and has an optical phase modulation means R1-1 for modulating the phase of the optical signal pulse train propagating in the first optical interference arm. , Mach-Zenda interference-type light intensity modulation means MZ-1 that functions as a Mach-Zenda-type interferometer,
An optical waveguide 18 that is connected to an external optical input port P-Data-In for inputting an optical signal pulse train Data-1 having information on the data pattern and guides the optical signal pulse train Data-1.
An optical input port PC1-1 connected to the optical waveguide 18 to which the optical signal pulse train Data-1 from the external optical input port P-Data-In is input, and an optical output port P-MZ-1- Optical input ports PC1-2 and optical output ports PC1-3 and PC1-4 to which optical signal pulse trains from either bar or the optical output port P-MZ-1-cross are input. Optical branch for branching and outputting the optical signal pulse train input from the optical input ports P-C1-2 and P-C1-1 to the optical output ports P-C1-3 and P-C1-4. Part C-1 and
An optical waveguide 14 that guides an optical signal pulse train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-C1-2.
Light from the optical output port PC1-3 connected to the optical input port PL1-1 for inputting the optical signal pulse train for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L that guides a signal pulse train and
Light from the optical output port PC1-4 connected to the optical input port P-R1-1 for inputting the optical signal pulse train for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R that guides a signal pulse train,
Optical signal pulse trains provided on the optical waveguide 15L or the optical waveguide 15R and simultaneously output from the optical output ports P-C1-3 and P-C1-4 are the optical input ports P-L1-1 and P-. An optical waveguide portion D-D-1 that produces an optical delay for adjusting the timing of reaching R1-1 so as to be equal to or greater than the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period.
In the optical signal buffer method using the circuit,
As the optical clock pulse train CLK-0, an RZ (Return to Zero) type optical signal pulse train is continuously input from the external optical input port P-OCLK-In-0.
The optical signal pulse train ERS-1 is synchronized with the clock of the optical clock pulse train CLK-0, synchronized with the period of the data pattern, and has the same length as the data length of the data pattern. Signal pulse train
After holding the data pattern in the circuit, the optical signal pulse train ERS-1 is input from the external optical input port P-ERS-In-0, and only during the data length of the optical signal pulse train ERS-1. The output of the optical clock pulse train CLK-0 is cut and output as the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out to the optical input port P-OCLK-In. ,
In the Mach-Zender interference type optical intensity modulation means MZ-1, the optical output port P is provided by the secondary optical clock pulse train CLK-1 which is input from the optical input port P-OCLK-In and whose output is cut. It is characterized in that a state in which an optical signal pulse train is not output from -MZ-1-bar and P-MZ-1-cross is created, the holding state of the data pattern is canceled, and the state is returned to the initial state.

The optical signal buffer method according to the twelfth invention for solving the above problems is
In the optical signal buffer memory circuit according to the eleventh invention.
As the light control type light intensity switch OSW-01,
It is located on the external optical input port P-OCLK-In-0 and the optical output ports P-MZ-0-bar and cross side located on the bar side with respect to the external optical input port P-OCLK-In-0. It is located on the optical waveguide of two second optical interference arms having an optical output port P-MZ-0-cross and one of the second optical interference arms, and propagates in the second optical interference arm. An optical phase modulation means L0 for modulating the phase of the optical signal pulse train, and an optical signal pulse train located on the optical waveguide of the other second optical interference arm and propagating in the second optical interference arm. Mach-Zenda interference-type optical intensity modulation means MZ-0, which has an optical phase-modulating means R0 for imparting modulation to the phase of the light, and functions as a Mach-Zender-type interferator.
An optical waveguide 55 that guides the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0, and
Optical input port PC0-1 and optical output port PC0-3 connected to the optical waveguide 55 to which the optical signal pulse train ERS-1 from the external optical input port P-ERS-In-0 is input. , P-C0-4, and the optical signal pulse train ERS-1 input from the optical input port P-C0-1 is branched and output to the optical output ports P-C0-3 and P-C0-4. Optical branch C-0 to make it
An optical signal pulse train from the optical output port PC0-3 connected to an optical input port P-L0-1 for inputting an optical signal pulse train for inducing an optical phase modulation action to the optical phase modulation means L0. Optical waveguide 54L that guides
An optical signal pulse train from the optical output port PC0-4 connected to an optical input port P-R0-1 for inputting an optical signal pulse train for inducing an optical phase modulation action to the optical phase modulation means R0. Optical waveguide 54R that guides
Optical signal pulse trains provided on the optical waveguide 54L or the optical waveguide 54R and simultaneously output from the optical output ports P-C0-3 and P-C0-4 are the optical input ports P-L0-1 and P-. An optical waveguide portion DD-0 that produces an optical delay for adjusting the timing of reaching R0-1 so as to be equal to or greater than the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period.
With
Either the optical output port P-MZ-0-bar or the optical output port P-MZ-0-clock is set as the optical output port P-OSW-01-Out, and the optical signal pulse train ERS-1 is not input. When the optical clock pulse train CLK-0 is output as the secondary optical clock pulse train CLK-1 and the optical signal pulse train ERS-1 is input, only during the data length of the optical signal pulse train ERS-1. It is characterized in that the output of the optical clock pulse train CLK-0 is cut and output as the secondary optical clock pulse train CLK-1.

The optical signal buffer method according to the thirteenth invention for solving the above problems is
In the optical signal buffer memory circuit according to the twelfth invention.
The optical signal pulse train ERS-1 is input from the external optical input port P-ERS-In-0, and the optical phase modulation means R0 and L0 are driven by using the input optical signal pulse train ERS-1. , The phase of the optical clock pulse train CLK-0 propagating in the two second optical interference arms of the Mach-Zender interference type light intensity modulation means MZ-0 is π-modulated, and the optical signal pulse train ERS- The output of the optical clock pulse train CLK-0 is cut only during the data length of 1, and the optical clock pulse train CLK-1 is used as the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out to the optical input port. It is characterized by outputting to P-OCLK-In.

According to the present invention, it is possible to add an optical delay of an arbitrary integral multiple to the stored optical signal length and output it, and there is a problem in the optical buffer memory described in [First Conventional Technique]. It is possible to overcome the problem that "the more patterns of adjustable optical delay amount are, the larger the optical circuit becomes", and there is a problem in the optical buffer memory described in [Second Conventional Technique]. It was caused by the deterioration of the optical signal waveform due to the influence of mixed noise such as ASE from the loss compensation optical amplifier used in the optical buffer memory circuit and the influence of the dispersion effect due to the optical waveguide in the optical buffer memory circuit. It is possible to overcome the fact that the optical delay limit that can be imparted is generated, and to impart an infinite amount of optical delay in principle.

Further, according to the present invention, a reset operation in the optical data buffer memory can be realized by a circuit and a method different from those in Patent Document 1. In this reset operation, the required amount of optical phase modulation amplitude at the time of buffer data erasure control can be suppressed to π, and as a result, power consumption and burnout risk can be effectively suppressed. As a result, it is possible to extend the circuit life.

Further, when the optical control type optical intensity switch OSW-01 has a configuration having a multi-mode optical waveguide WG-M, the configuration of the optical circuit can be simplified and the reliability can be improved.

It is the schematic which shows an example (Example 1) of the optical signal buffer memory circuit by this invention. It is the schematic of the optical circuit of the optical control type optical intensity switch OSW-01 used in the optical signal buffer memory circuit shown in FIG. It is a timing chart of various optical signals in the optical signal buffer memory circuit shown in FIG. (A) to (d) are schematic views showing a configuration example of an optical-optical phase modulation means. (A) to (c) are schematic views showing a configuration example of an optical-optical phase modulation means. (A) to (c) are schematic views showing a configuration example of an optical-optical phase modulation means. (A) and (b) are schematic views showing a configuration example of an optical-optical phase modulation means. (A) to (c) are block diagrams which show the structural example of the optical branch part. (A) to (c) are block diagrams which show the structural example of the optical branch part. (A) to (c) are block diagrams which show the structural example of the optical branch part. It is a schematic diagram which shows another example (Example 2) of the optical circuit of the optical control type optical intensity switch OSW-01 used in the optical signal buffer memory circuit shown in FIG. 1. It is a schematic diagram which shows another example (Example 3) of the optical circuit of the optical control type optical intensity switch OSW-01 used in the optical signal buffer memory circuit shown in FIG. 1. It is the schematic which shows the modification of the optical circuit shown in FIG. It is a schematic diagram which shows another example (Example 4) of the optical circuit of the optical control type optical intensity switch OSW-01 used in the optical signal buffer memory circuit shown in FIG. 1. It is the schematic which shows the modification of the optical circuit shown in FIG. It is the schematic which shows the other modification of the optical circuit shown in FIG. It is the schematic which shows the other modification of the optical circuit shown in FIG. It is the schematic which shows an example of the optical buffer circuit which consists of the optical delay waveguide array, the optical switch, and the optical coupler which have been studied conventionally. It is the schematic which shows an example of the conventional optical circuit type buffer circuit which consists of an optical waveguide loop, an optical amplifier for propagation compensation, and an optical switch. It is a schematic diagram which shows the conventional optical signal buffer memory circuit.

Hereinafter, embodiments of the optical signal buffer memory circuit and the optical signal buffer method according to the present invention will be described with reference to the drawings.

[Example 1]
FIG. 1 is a schematic view showing an optical signal buffer memory circuit of this embodiment, and FIG. 2 is an optical circuit of an optical control type optical intensity switch OSW-01 used in the optical signal buffer memory circuit shown in FIG. It is a schematic diagram. Further, FIG. 3 is a timing chart of various optical signals in the optical signal buffer memory circuit shown in FIG.

(Basic configuration)
In the optical signal buffer memory circuit of this embodiment, the reference numeral P-OCLK-In-0 is an external device for inputting the optical clock pulse train CLK-0 as shown in "OC source / CLK-0" in FIG. It is an optical input port. As the optical clock pulse train CLK-0, "an RZ (Return to Zero) type optical clock pulse train output from the clock signal light source and having a constant peak optical power" is continuously input.

Further, the reference numeral P-ERS-In-0 is an external optical input port for inputting the optical signal pulse train ERS-1 as shown in "ERS ctl./ERS-1" of FIG. As the optical signal pulse train ERS-1, "an optical signal pulse train for control of erasing stored information input when resetting information (buffer data) stored (held) in the optical signal buffer memory circuit" is input.

Further, the reference numeral P-Data-In is an external optical input port for inputting the optical signal pulse train Data-1 as shown in "OD source / Data-1" of FIG. As the optical signal pulse sequence Data-1, "an optical signal pulse sequence for data input for the purpose of storing in the optical signal buffer memory circuit" is input. The optical signal pulse train Data-1 has information on a data pattern held in the optical signal buffer memory circuit.

Further, the reference numeral P-FF-In is an external optical input port for inputting the optical signal pulse train FF-1 as shown in "FF inch / FF-1" of FIG. As the optical signal pulse train FF-1, "it is input when performing a so-called flip-flop operation in which all the marks (1) and spaces (0) of the information of the data pulse train stored in the optical signal buffer memory circuit are inverted. An optical signal pulse train for flip-flop control is input.

Further, reference numeral C-1 is an optical branching portion having optical input ports P-C1-1 and P-C1-2, optical output ports P-C1-3, and P-C1-4. In the optical branching portion C-1, the optical signal pulse train Data-1 from the external optical input port P-Data-In is input from the optical input port PC1-1 via the optical waveguide 18 and branched. Then, the light is output from the optical output ports PC1-3 and PC1-4, and the light of the Mach-Zender interference type light intensity modulation means (hereinafter abbreviated as light intensity modulation means) MZ-1 described later. The optical signal pulse train from the output port P-MZ-1-bar is input and branched from the optical input port PC1-2 via the optical waveguide 14, and the optical output ports PC1-3 and P- It is output from C1-4.

The light intensity modulation means MZ-1 is an optical circuit unit used as a Mach-Zender interference type light intensity modulation means, and has two left and right first optical interference arms (optical waveguides 11R, 12R, 13R and optical waveguide 11L, 12L, 13L), and in the optical waveguide 11R and the optical waveguide 11L, a part is arranged close to each other to form a directional coupler, and in the optical waveguide 13R and the optical waveguide 13L, a part is close to each other. To form a directional coupler.

Further, the reference numerals R1-1, R1-2, L1-1, and L1-2 are input to the light intensity modulation means MZ-1 from the optical input port P-OCLK-In, and the left and right sides 2 of the light intensity modulation means MZ-1. It is an optical-optical phase modulation means (hereinafter abbreviated as optical phase modulation means) that modulates the phase of an optical signal pulse train (input light signal pulse train, modulated light signal pulse train, which will be described later) propagating through the first optical interference arm. ..

The optical input port P-OCLK-In is via an optical output port P-OSW-01-Out of an optical control type optical intensity switch (hereinafter abbreviated as an optical intensity switch) OSW-01, which will be described later, and an optical waveguide 53. The secondary optical clock pulse train CLK-1 (CLK-ERS-Plus), which will be described later, is input to the optical intensity modulation means MZ-1 which is connected and functions as an optical gate switch.

The optical phase modulation means R1-1, R1-2, L1-1, L1-2 are arranged between two directional couplers. Specifically, the optical phase modulation means R1-1 is between the optical waveguide 11R and the optical waveguide 12R, and the optical phase modulation means R1-2 is between the optical waveguide 12R and the optical waveguide 13R. -1 is arranged between the optical waveguide 11L and the optical waveguide 12L, and the optical phase modulation means L1-2 is arranged between the optical waveguide 12L and the optical waveguide 13L. That is, the optical phase modulation means R1-2 is located on the rear side of the optical phase modulation means R1-1, and the optical phase modulation means L1-2 is located on the rear side of the optical phase modulation means L1-1.

Here, the input optical signal pulse train is an optical signal pulse train obtained by branching the secondary optical clock pulse train CLK-1 with a directional coupler, and the modulated optical signal pulse train is a phase modulation means R1-1. This is an optical signal pulse train after undergoing optical phase modulation at L1-1.

Further, the reference numeral P-MZ-1-cross is an optical output port that outputs an optical signal pulse train from the cross side to the optical input port P-OCLK-In of the optical intensity modulation means MZ-1, that is, the optical intensity modulation means. This is an optical output port that outputs an optical signal pulse train Output from MZ-1.

Further, the reference numeral P-MZ-1-bar is an optical output port that outputs an optical signal pulse train from the bar side with respect to the optical input port P-OCLK-In of the optical intensity modulation means MZ-1, that is, the optical intensity modulation means. This is an optical output port that outputs a buffered optical signal pulse train CLK-1-out-DMZ-1 that serves as light intensity-modulated light of MZ-1.

Further, reference numeral 15L guides the optical signal pulse train from the optical output port PC1-3 of the optical branching portion C-1 to the optical input port PL1-1 for inputting to the optical phase modulation means L1-1. It is an optical wave guide.

Further, reference numeral 15R guides the optical signal pulse train from the optical output port CC1-4 of the optical branching portion C-1 to the optical input port P-R1-1 for inputting to the optical phase modulation means R1-1. It is an optical wave guide.

Further, reference numeral C-3 is an optical branching portion having optical input ports P-C3-1 and P-C3-2, and optical output ports P-C3-3 and P-C3-4. In the optical branching portion C-3, the optical signal pulse train FF-1 from the external optical input port P-FF-In is input from the optical input port PC3-2 and branched via the optical waveguide 21. Therefore, the light is output from the optical output ports P-C3-3 and P-C3-4.

Further, reference numeral 22L guides the optical signal pulse train from the optical output port PC3-3 of the optical branching portion C-3 to the optical input port PL1-2 for inputting to the optical phase modulation means L1-2. It is an optical wave guide.

Further, reference numeral 22R guides the optical signal pulse train from the optical output port P-C3-4 of the optical branching portion C-3 to the optical input port P-R1-2 for inputting to the optical phase modulation means R1-2. It is an optical wave guide.

Further, the reference numerals D-D-1 impart an optical propagation delay difference to one of the two optical signal pulse trains simultaneously output from the optical output ports PC1-3 and PC1-4 of the optical branching portion C-1. It is an optical propagation delay difference imparting unit for this purpose. In the optical propagation delay difference imparting unit D-D-1, the timing at which the optical signal pulse train reaches the optical input port P-L1-1 of the optical phase modulation means L1-1 and the optical input port of the optical phase modulation means R1-1. The optical propagation delay difference from the timing at which the optical signal pulse train reaches P-R1-1 is adjusted to be "greater than or equal to the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period". The light propagation delay difference imparting unit DD-1 is arranged in either the optical waveguide 15L or the optical waveguide 15R. Here, the optical waveguide portion having an optical path length that causes the optical propagation delay difference is arranged in the optical waveguide 15L. are doing.

Further, reference numeral DD-2 imparts an optical propagation delay difference to one of two optical signal pulse trains simultaneously output from the optical output ports PC3-3 and CC3-4 of the optical branching portion C-3. It is an optical propagation delay difference imparting unit for this purpose. In the optical propagation delay difference imparting unit DD-2, the timing at which the optical signal pulse train reaches the optical input ports P-L1-2 of the optical phase modulation means L1-2 and the optical input port of the optical phase modulation means R1-2. The optical propagation delay difference from the timing at which the optical signal pulse train reaches P-R1-2 is adjusted to be "more than or equal to the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period". The light propagation delay difference imparting unit DD-2 is arranged in either the optical waveguide 22L or the optical waveguide 22R. Here, the optical waveguide portion having an optical path length that causes the optical propagation delay difference is arranged in the optical waveguide 22L. are doing.

Here, the optical waveguide 14 is connected to the optical output port P-MZ-1-bar to circulate the optical signal pulse train CLK-1-out-DMZ-1 to the optical branching portion C-1. An optical waveguide 14 may be connected to the optical output port P-MZ-1-cross so that the optical signal pulse train CLK-1-out-DMZ-1 is circulated around the optical branching portion C-1. In that case, the light propagation delay difference imparting unit DD-1 is provided on the optical waveguide 15R, and the light propagation delay difference imparting unit DD-2 is provided on the optical waveguide 22R.

Further, the optical signal pulse trains FF-1 and ERS-1 for controlling the optical signal buffer memory circuit of this embodiment use, for example, one or each individual generator for generating these optical signal pulse trains, and are used for optical light. External optical input port P- in synchronization with clock pulse train CLK-0, secondary optical clock pulse train CLK-1, and optical signal pulse train Data-1 (or optical signal pulse train CLK-1-out-DMZ-1). Input may be performed from FF-In and P-ERS-In-0, respectively.

Further, the optical intensity switch OSW-01 is an optical control type optical intensity switch that outputs an output obtained by cutting the output of the optical clock pulse train CLK-0 or the output of the optical clock pulse train CLK-0 as a secondary optical clock pulse train CLK-1. Is. When cutting the output of the optical clock pulse train CLK-0, the output of the "optical clock pulse train while the optical signal pulse train ERS-1 is being input" is cut from the optical clock pulse train CLK-0, and the optical pulse is generated. It is in a state where it is not output.

As described above, in the optical signal buffer memory circuit of this embodiment, the difference from the conventional optical signal buffer memory circuit shown in FIG. 20 is that the optical signal buffer memory circuit does not have the optical branching portion C-2, and the optical signal pulse train Data-. The external optical input port P-Data-In for inputting 1 is connected to the optical branching portion C-1 via the optical waveguide 18, and the external optical input port P for inputting the optical clock pulse train CLK-0. -OCLK-In-0 and the external optical input port P-ERS-In-0 for inputting the optical signal pulse train ERS-1 are connected to the optical intensity switch OSW-01, and the optical intensity switch OSW-01 is an optical waveguide 53. It is a point connected to the input port P-OCLK-In via. Further, the optical clock pulse train CLK-0 in the optical signal buffer memory circuit of this embodiment is the optical clock pulse train CLK-1 in the conventional optical signal buffer memory circuit shown in FIG. 20, and is the optical signal buffer memory circuit of this embodiment. As described above, the secondary optical clock pulse train CLK-1 in the above is an output obtained by cutting the output of the optical clock pulse train CLK-0 or the output of the optical clock pulse train CLK-0. The detailed optical circuit configuration of the light intensity switch OSW-01 will be described with reference to FIG.

In the light intensity switch OSW-01, the external light input port P-OCLK-In-0 is input to the light intensity modulation means MZ-0 described later, which functions as an optical gate switch. Therefore, as described above, an optical clock pulse train is used. CLK-0 is input. Further, as described above, the optical signal pulse train ERS-1 is input to the external optical input port P-ERS-In-0.

The light intensity modulation means MZ-0 is an optical circuit unit used as a Mach-Zender interference type light intensity modulation means, and has two left and right second optical interference arms (optical waveguides 51R and 52R and optical waveguides 51L and 52L). In the optical waveguide 51R and the optical waveguide 51L, a part of the optical waveguide 51R and the optical waveguide 51L are arranged close to each other to form a directional coupler. It constitutes a directional coupler.

Further, in the light intensity modulation means MZ-0, the reference numerals P-MZ-0-bar and P-MZ-0-cross are optical outputs located on the bar side of the external optical input port P-OCLK-In-0, respectively. It is an optical output port located on the cross side with the port. Either the optical output port P-MZ-0-bar or the optical output port P-MZ-0-cross is designated as the optical output port P-OSW-01-Out.

Further, the symbols R0 and L0 are input to the light intensity modulation means MZ-0 from the external light input port P-OCLK-In-0 and propagate through the two left and right second optical interference arms of the light intensity modulation means MZ-0. It is an optical-optical phase modulation means (hereinafter, abbreviated as an optical phase modulation means) for modulating the phase of an optical signal pulse train.

The optical phase modulation means R0 and L0 are respectively arranged on two optical waveguide type interference arms of the light intensity modulation means MZ-0. Specifically, the optical phase modulation means R0 is arranged between the optical waveguide 51R and the optical waveguide 52R, and the optical phase modulation means L0 is arranged between the optical waveguide 51L and the optical waveguide 52L. That is, the optical phase modulation means R0 and L0 are arranged between the two directional couplers of the light intensity modulation means MZ-0.

Further, reference numeral C-0 is an optical branching portion having optical input ports P-C0-1 and P-C0-2, and optical output ports P-C0-3 and P-C0-4. In this optical branching portion C-0, the optical signal pulse train ERS-1 from the external optical input port P-ERS-In-0 is input from the optical input port P-C0-1 via the optical waveguide 55 and branched. The light is output from the optical output ports P-C0-3 and P-C0-4.

Further, reference numeral 54L is an optical waveguide that guides the optical signal pulse train from the optical output port P-C0-3 of the optical branching portion C-0 to the optical input port P-L0-1 for inputting to the optical phase modulation means L0. Is.

Further, reference numeral 54R is an optical waveguide that guides the optical signal pulse train from the optical output port P-C0-4 of the optical branching portion C-0 to the optical input port P-R0-1 for inputting to the optical phase modulation means R0. Is.

Further, reference numeral DD-0 imparts an optical propagation delay difference to one of two optical signal pulse trains simultaneously output from the optical output ports PC0-3 and PC0-4 of the optical branching portion C-0. It is an optical propagation delay difference imparting unit for this purpose. In the optical propagation delay difference imparting unit DD-0, the timing at which the optical signal pulse train reaches the optical input port P-L0-1 of the optical phase modulation means L0 and the optical input port P-R0-of the optical phase modulation means R0 The optical propagation delay difference from the timing at which the optical signal pulse train reaches 1 is adjusted to be "greater than or equal to the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition cycle". The light propagation delay difference imparting unit DD-0 is arranged in either the optical waveguide 54L or the optical waveguide 54R, but here, the optical waveguide portion having an optical path length that causes the optical propagation delay difference is arranged in the optical waveguide 54L. are doing.

(motion)
Next, the operation in the optical signal buffer memory circuit of this embodiment, specifically, data retention (buffering), flip-flop, and storage data erasure will be described with reference to FIGS. 1 to 3.

(Operation-Data retention)
In the standard Mach-Zender interference type light intensity modulation means, the state in which no phase difference occurs when light propagates through the two light interference arms constituting the interferometer is the state in which the modulation drive is not performed. At this time, 100% of the optical signal is output from the cross side with respect to the input side. On the other hand, when the phase difference is π, 100% of the optical signal is output from the bar side.

Therefore, in the light intensity modulation means MZ-0 of the light intensity switch OSW-01 shown in FIG. 2, the optical clock pulse train CLK-0 is input from the external light input port P-OCLK-In-0, and the external light input. When nothing is input from the port P-ERS-In-0, the optical clock pulse train CLK-0 is output from the 100% optical output port P-MZ-0-cross and from the optical output port P-MZ-0-bar. Light output cannot be obtained. Then, assuming that the optical output port P-MZ-0-cross is the optical output port P-OSW-01-Out, the optical clock pulse train from the optical output port P-OSW-01-Out is as shown in FIG. The same secondary optical clock pulse train CLK-1 as CLK-0 is output.

Further, in the optical intensity modulation means MZ-1 of the optical signal buffer memory circuit shown in FIG. 1, when the secondary optical clock pulse train CLK-1 is input from the optical input port P-OCLK-In, it is secondary. The target optical clock pulse train CLK-1 is output from the 100% optical output port P-MZ-1-cross, and no optical output can be obtained from the optical output port P-MZ-1-bar (the optical buffer memory provides any information). It is an empty state that is not held: initial state).

At this time, the secondary optical clock pulse train CLK-1 is input to the optical input port P-OCLK-In of the light intensity modulation means MZ-1, and as shown in FIG. 3, the optical clock pulse train CLK-0 and When the optical signal pulse train Data-1 synchronized with the secondary optical clock pulse train CLK-1 is input from the external optical input port P-Data-In, the optical phase modulation means R1-1 and L1-1 are driven. Then, the phase of the input optical signal pulse train (secondary optical clock pulse train CLK-1) propagating in the left and right first optical interference arms of the light intensity modulation means MZ-1 is π-modulated to π-modulate the input light. Each pulse in the signal pulse train will be turned on or off.

Then, π phase modulation is applied only to the pulse of the input optical signal pulse train corresponding to the pulse at the position marked Mark (1) of the optical signal pulse train Data-1, and the Space (0) of the optical signal pulse train Data-1 and Since the pulse of the input optical signal pulse train corresponding to the pulse at the position is not subjected to phase modulation, the optical output port P-MZ-of the optical intensity modulation means MZ-1 has the same data pattern as the optical signal pulse train Data-1. It will be output from 1-bar. In FIG. 3, as an example of the optical signal pulse train Data-1, an 8-bit optical signal pulse train of “10101010” is input.

Then, the optical signal pulse sequence CLK-1-out-DMZ-1 output from the P-MZ-1-bar, which has the same data pattern as the optical signal pulse sequence Data-1, passes through the optical branching portion C-1. , Since the data is input to the optical phase modulation means R1-1 and L1-1 to induce optical phase modulation, it propagates in the left and right first optical interference arms of the optical intensity modulation means MZ-1 even in the next circuit. The input optical signal pulse train is subjected to the same optical phase modulation as above by the optical signal pulse train CLK-1-out-DMZ-1 having the same data pattern as the main optical signal pulse train Data-1, and the main light. The same data pattern as the signal pulse train Data-1 is repeatedly output from the optical output port P-MZ-1-bar of the optical intensity modulation means MZ-1, and as a result, "Buffering State / CLK" in FIG. As shown in "-1-out-DMZ-1" (see the optical signal pulse train for three cycles of N = 1 to 3 in FIG. 3), the same data pattern as the optical signal pulse train Data-1 is the optical signal. It will be held in the buffer memory circuit as a series of drive states. From the optical output port P-MZ-1-cross of the optical signal buffer memory circuit, as shown in "Autoput" of FIG. 3 (optical signals for 3 cycles of N = 1 to 3 in FIG. 3). (Refer to the pulse train), the inverted data pattern of the optical signal pulse train Data-1 is output.

At this time, as in the optical buffer memory described in the [second prior art], the signal data pattern is held by continuously propagating the main optical pulse train through the optical waveguide loop while repeating optical amplification. Unlike the case, in this embodiment, the “lighted phase modulated signal light” is used by using the optical signal pulse train Data-1 or the optical signal pulse train CLK-1-out-DMZ-1 which is the “optical phase modulation control signal light”. By turning on or off each pulse of the secondary optical clock pulse sequence CLK-1, a new optical signal pulse sequence having the same data pattern as the optical signal pulse sequence Data-1 is duplicated (copied). Since the influence of mixed noise such as ASE from the loss compensation optical amplifier used in the optical buffer memory circuit and the influence of the dispersion effect due to the optical waveguide in the optical buffer memory circuit can be eliminated, the optical signal waveform is deteriorated. It is possible to realize a remarkable characteristic that the resulting limit of optical delay that can be applied is not generated.

(Operation-Flip-flop)
As described above, in a state where the same data pattern as that of the optical signal pulse train Data-1 is held in the optical signal buffer memory circuit as a series of driving states, further, “FF ctl./FF−” in FIG. As shown in "1", it is synchronized with the secondary optical clock pulse train CLK-1 (optical clock pulse train CLK-0) input from the optical input port P-OCLK-In of the optical intensity modulation means MZ-1. In addition, the period with the same data pattern as the optical signal pulse train Data-1 already held as a series of driving states is synchronized, and the optical signal pulse train FF-1 having the same length as the data length of this data pattern. Is input from the external optical input port P-FF-In, it drives the optical phase modulation means R1-2 and L1-2 to move through the left and right first optical interference arms of the optical intensity modulation means MZ-1. The phase of the propagating modulated light signal pulse train (phase-modulated input light signal pulse train) is π-modulated to turn on or off each pulse of the modulated light signal pulse train.

Then, due to the effect of the series of driving states already held, in total including the optical phase modulation given by π in the optical phase modulation means R1-1 and L1-1, the left and right of the light intensity modulation means MZ-1 are left and right. The phase modulation suffered by the input optical signal pulse train propagating in the first optical interference arm is Mark (1) of the optical signal pulse train Data-1 (or the optical signal pulse train CLK-1-out-DMZ-1). 2π phase modulation is applied to the pulse of the input optical signal pulse train corresponding to the pulse at the position, and the optical signal pulse train Data-1 (or optical signal pulse train CLK) to which the phase modulation is not applied in the previous lap is applied. Π phase modulation is applied to the pulse of the input optical signal pulse train corresponding to the pulse at the position (0) of -1-out-DMZ-1).

As a result, the optical signal pulse train subjected to these optical phase modulation becomes a data pattern inverted from the optical signal pulse train Data-1, and is transmitted from the optical output port P-MZ-1-bar of the optical intensity modulation means MZ-1. The optical signal pulse trains that are output and at the same time undergo these optical phase modulation have the same data pattern as the optical signal pulse train Data-1, and the optical output port P-MZ-1-cross of the optical intensity modulation means MZ-1. The so-called flip flop operation is realized. As a result, as shown in "Buffering State / CLK-1-out-DMZ-1" in FIG. 3 (see the optical signal pulse train for two cycles of N = 4 to 5 in FIG. 3), the optical signal pulse train. A data pattern inverted from Data-1 (8-bit optical signal pulse train of "01010101") is held in the optical signal buffer memory circuit as a series of driving states. From the optical output port P-MZ-1-cross of the optical signal buffer memory circuit, as shown in "Autoput" in FIG. 3 (optical signals for two cycles of N = 4 to 5 in FIG. 3). (Refer to the pulse train), the same data pattern as the optical signal pulse train Data-1 is output.

(Operation-Reset)
As described above, in a state where the same data pattern or inverted data pattern as that of the optical signal pulse train Data-1 is held in the optical signal buffer memory circuit as a series of driving states, the “ERS ctl./ERS” of FIG. As shown in "-1", it is synchronized with the clock of the secondary optical clock pulse train CLK-1 (optical clock pulse train CLK-0) and is already held (stored and maintained) in the optical signal buffer memory circuit as a series of drive states. ) The RZ-type optical signal pulse train ERS-1 has the same period as the data pattern or inverted data pattern of the optical signal pulse train Data-1 and has the same length as the data length of this data pattern. When input is input from the external optical input port P-ERS-In-0, the optical phase modulation means R0 and L0 are driven by using the input optical signal pulse train ERS-1, and the optical intensity modulation means MZ-0 The phase of the optical clock pulse train CLK-0 propagating in the two second optical interference arms is π-modulated.

Then, during the time when the optical signal pulse train ERS-1 is input (only during the data length of the optical signal pulse train ERS-1), the output of the optical clock pulse train CLK-0 is cut and the secondary optical clock is cut. The pulse train CLK-1 (CLK-ERS-Plus) is output from the optical output port P-OSW-01-Out. By inputting and supplying this from the optical input port P-OCLK-In, the optical output port during the time during which the optical signal pulse train ERS-1 is input (only during the data length of the optical signal pulse train ERS-1). Creates a state in which no optical pulse is output from P-MZ-1-bar and P-MZ-1-cross, eliminates the data pattern retention state, and eliminates the initial state as an optical buffer memory (the optical buffer memory provides any information). It will realize the operation to return to the empty state that is not held.

(Structure of optical phase modulation means of optical signal buffer memory circuit)
In the above-mentioned optical signal buffer memory circuit, the waveguide portion is composed of a low-loss semiconductor waveguide, and the optical phase modulation means R0, R1-1, R1-2, L0, L1-1, and L1-2 are used as semiconductors. An optical amplifier (SOA) is used, an optical semiconductor circuit consisting of the optical phase modulation means shown in FIGS. 4 to 7 is used, a quantum dot type SOA (QD-SOA) is used, or a semiconductor EA is used. (Electro-Absorption) A modulator is used in a constant voltage drive, and the whole is integrated with an optical semiconductor.

Alternatively, in the optical circuit of this embodiment, the optical waveguide portion is composed of a PLC (quartz-based planar light wave circuit), and the optical phase modulation means R0, R1-1, R1-2, L0, L1-1, L1-2. As a result, SOA is used, or a PLC-optical semiconductor hybrid circuit composed of optical phase modulation means shown in FIGS. 4 to 7 is used, or QD-SOA is used, or a semiconductor EA modulator is determined. As a configuration used for voltage drive, the whole is manufactured by a hybrid of PLC and an optical semiconductor (see Non-Patent Document 4).

Alternatively, a photonic crystal waveguide is used for the optical waveguide portion, and quantum dot groups are embedded in the core layer in the optical phase modulation means R0, R1-1, R1-2, L0, L1-1, and L1-2. , The whole is integrally integrated and manufactured (see Non-Patent Document 5).

Therefore, it is composed of optical phase modulation means used as optical phase modulation means R0, R1-1, R1-2, L0, L1-1, L1-2 with reference to FIGS. 4 (a) to 7 (b). An optical semiconductor circuit will be described. The optical semiconductor circuits shown in FIGS. 4 (a) to 7 (b) are, for example, manufactured by being integrated in an optical semiconductor circuit of a coplanar substrate type. In FIGS. 4A to 7B, the same components are designated by the same reference numerals.

Further, here, the two input optical signal pulse trains are referred to as "lighted phase modulation signal light" and "optical phase modulation control signal light" for convenience. Further, in FIGS. 4A to 7B, a case where the signal light is input from the left side in the figure and output from the right side will be described, but the left and right sides may be reversed, and one optical interference arm and the other may be used. The input and output of the signal light to the optical interference arm may be opposite to each other. Therefore, the reference numerals a1 to a12 are referred to as "optical input / output ports".

In FIGS. 4A to 7B, the multimode interference coupler b1 has two optical input / output ports a9 and a10 on one side and two optical input / output ports a5 and a6 on the other side. The mode interference coupler b2 includes two optical input / output ports a7 and a8 on one side and two optical input / output ports a11 and a12 on the other side.

Further, in FIGS. 4A to 7B, the two optical input / output ports a1 and a2 on one side of the entire optical circuit are the two optical input / output waveguides e1 and e2 on one side of the entire optical waveguide. Is connected to the optical input / output ports a9 and a10 on one side of the multimode interference coupler b1, respectively. Further, the optical input / output ports a11 and a12 on the other side of the multimode interference coupler b2 are the two lights on the other side of the entire optical circuit via the two optical input / output waveguides e3 and e4 on the other side of the entire optical circuit. It is connected to the input / output ports a3 and a4, respectively.

Further, in FIGS. 4A to 7B, the optical input / output ports a5 and a6 on the other side of the multimode interference coupler b1 are connected to the optical waveguides e5 and e6, respectively, and the multimode The optical input / output ports a7 and a8 on one side of the interference coupler b2 are connected to the optical waveguides e7 and e8, respectively, and the optical waveguides e5 and e7 and the optical waveguides e6 and e8 form two optical interference arms. ing. Then, the optical phase modulation unit c1 or the optical phase modulation unit c1 and the optical phase adjustment unit d1 are connected to one of the optical interference arms (optical waveguides e5, e7), and the other optical interference arm (optical waveguides e6, e8). Is connected to the optical phase modulation unit c2 or the optical phase modulation unit c2 and the optical phase adjustment unit d2. A specific connection configuration will be described below.

Specifically, in FIG. 4A, one side of the optical phase modulation unit c1 is connected to the optical waveguide e5, the other side of the optical phase modulation unit c1 is connected to the optical waveguide e7, and the optical phase is connected to the optical waveguide e6. One side of the modulation unit c2 is connected, and the other side of the optical phase modulation unit c2 is connected to the optical waveguide e8. Further, in FIGS. 4B and 5A, one side of the optical phase modulation unit c1 is connected to the optical waveguide e5, and the other side of the optical phase modulation unit c1 is connected to one side of the optical phase adjustment unit d1. The other side of the optical phase adjusting unit d1 is connected to the optical waveguide e7, one side of the optical phase modulation unit c2 is connected to the optical waveguide e6, and the other side of the optical phase modulation unit c2 is connected to the optical waveguide e8. Further, in FIGS. 4 (c) and 5 (b), one side of the optical phase modulation unit c1 is connected to the optical waveguide e5, and the other side of the optical phase modulation unit c1 is connected to the optical waveguide e7. One side of the optical phase modulation unit c2 is connected to the optical phase modulation unit c2, the other side of the optical phase modulation unit c2 is connected to one side of the optical phase adjustment unit d2, and the other side of the optical phase adjustment unit d2 is connected to the optical waveguide e8. Further, in FIGS. 4D and 5C, one side of the optical phase modulation unit c1 is connected to the optical waveguide e5, and the other side of the optical phase modulation unit c1 is connected to one side of the optical phase adjustment unit d1. The other side of the optical phase adjusting unit d1 is connected to the optical waveguide e7, one side of the optical phase modulation unit c2 is connected to the optical waveguide e6, and the other side of the optical phase modulation unit c2 is connected to one side of the optical phase adjusting unit d2. The other side of the optical phase adjusting unit d2 is connected to the optical waveguide e8.

Further, in FIG. 6A, one side of the optical phase adjusting unit d1 is connected to the optical waveguide e5, the other side of the optical phase adjusting unit d1 is connected to one side of the optical phase modulation unit c1, and the optical phase modulation unit c1 is connected. The other side is connected to the optical waveguide e7, one side of the optical phase modulation unit c2 is connected to the optical waveguide e6, and the other side of the optical phase modulation unit c2 is connected to the optical waveguide e8. Further, in FIG. 6B, one side of the optical phase modulation unit c1 is connected to the optical waveguide e5, the other side of the optical phase modulation unit c1 is connected to the optical waveguide e7, and the optical phase adjustment unit d2 is connected to the optical waveguide e6. One side is connected, the other side of the optical phase adjusting unit d2 is connected to one side of the optical phase modulation unit c2, and the other side of the optical phase modulation unit c2 is connected to the optical waveguide e8. Further, in FIG. 6C, one side of the optical phase adjusting unit d1 is connected to the optical waveguide e5, the other side of the optical phase adjusting unit d1 is connected to one side of the optical phase modulation unit c1, and the optical phase modulation unit c1 is connected. The other side is connected to the optical waveguide e7, one side of the optical phase adjusting unit d2 is connected to the optical waveguide e6, the other side of the optical phase adjusting unit d2 is connected to one side of the optical phase modulation unit c2, and the optical phase modulation unit is connected. The other side of c2 is connected to the optical waveguide e8.

Further, in FIG. 7A, one side of the optical phase modulation unit c1 is connected to the optical waveguide e5, the other side of the optical phase modulation unit c1 is connected to one side of the optical phase adjustment unit d1, and the optical phase adjustment unit d1 The other side is connected to the optical waveguide e7, one side of the optical phase adjusting unit d2 is connected to the optical waveguide e6, the other side of the optical phase adjusting unit d2 is connected to one side of the optical phase modulation unit c2, and the optical phase modulation unit is connected. The other side of c2 is connected to the optical waveguide e8. Further, in FIG. 7B, one side of the optical phase adjusting unit d1 is connected to the optical waveguide e5, the other side of the optical phase adjusting unit d1 is connected to one side of the optical phase modulation unit c1, and the optical phase modulation unit c1 is connected. The other side is connected to the optical waveguide e7, one side of the optical phase modulation unit c2 is connected to the optical waveguide e6, the other side of the optical phase modulation unit c2 is connected to one side of the optical phase adjustment unit d2, and the optical phase adjustment unit is connected. The other side of d2 is connected to the optical waveguide e8.

Then, in the multimode interference coupler b1, when "lighted phase modulation signal light" and "optical phase modulation control signal light" are input from the two optical input / output ports a1 and a2 via the optical input / output ports a9 and a10, respectively. , The "lighted phase modulation signal light" and the "optical phase modulation control signal light" input from the optical input / output ports a1 and a2 are branched, and one of the branched "lighted phase modulation signal light" and "optical phase modulation" are branched. One of the "control signal light" is combined and output from the optical input / output port a5 (this is referred to as the first signal light for convenience), and the branched "lighted phase modulated signal light" is used. The other and the other of the "optical phase modulation control signal light" are combined and output from the optical input / output port a6 (this is referred to as a second signal light for convenience).

Similarly, in the multimode interference coupler b2, when the "first signal light" and the "second signal light" are input from the two optical input / output ports a7 and a8, respectively, they are input from the optical input / output ports a7 and a8. The "first signal light" and the "second signal light" are branched, and one of the branched "first signal light" and one of the "second signal light" are combined to enter light. Output from the output port a11, the other of the branched "first signal light" and the other of the "second signal light" are combined and output from the optical input / output port a12.

Further, the optical phase modulation units c1 and c2 are optical phase modulation units having an optical waveguide structure having a property that the refractive index changes according to the light intensity of the "optical phase modulation control signal light", and the optical phase modulation units are It is either an optical semiconductor amplifier (SOA) having an optical waveguide structure, an optical waveguide structure including a quantum dot layer, or a semiconductor EA modulator in a constant voltage drive state. Further, the optical phase adjusting units d1 and d2 can adjust the phase of the signal light according to the injection current amount.

As described above, as the optical phase modulation means, the two multimode interference couplers (MMI) b1 and b2 are optical phase modulation units c1 and c2 (for example, an optical semiconductor amplifier (SOA)) that perform a function of adding optical phase modulation. The Mach-Zenda interference circuit connected by the optical interference arm including)) is used.

Then, as shown in FIG. 4 (a), the lengths of the two optical interference arms are strictly adjusted at the time of manufacture, or FIGS. 4 (b) to (d) and FIGS. 5 (a) to 7 are shown. As shown in (b), additional phase adjusting units d1 and d2 capable of adjusting the phase of the optical signal according to the amount of injection current are provided on one or both of the optical interference arms, and the phase adjusting units d1 and d2 are used. Therefore, the optical path length of the optical interference arm is strictly adjusted at the time of use.

With such a configuration, "optical phase modulation control signal light" is input to any one of the optical input / output ports a1, a2, a3, and a4, and any one of the other optical input / output ports. When "lighted phase modulated signal light" is input to the port, the "lighted phase modulated signal light" that has undergone optical phase modulation is selectively output to the remaining two optical input / output ports, and the remaining two other optical input / output ports are selectively output. It is possible to selectively output "optical phase modulation control signal light" to the optical input / output port. In this way, the optical input / output port for inputting the "optical phase modulation control signal light" and the "lighted phase modulated signal light", and the "lighted phase modulated signal light" and the "optical phase modulated light" that have undergone optical phase modulation. The optical input / output port for outputting the "control signal light" can be appropriately selected, and the desired signal light can be selectively output to the desired optical input / output port (signal light-control signal light separation operation).

For example, when the "lighted phase modulation signal light" is input from the optical input / output port a1 and the "optical phase modulation control signal light" is input from the optical input / output port a2, the optical phase modulation by the optical interference arm is performed. , The "lighted phase modulation signal light" from the optical input / output port a1 is selectively output to either the optical input / output port a3 or a4, and the "optical phase modulation control signal light" from the optical input / output port a2. Is output to an optical input / output port a4 or a3, which is an optical input / output port different from the optical input / output port that selectively outputs the above-mentioned "light-illuminated phase-modulated signal light". As a result, the "optical phase modulation control signal light" is input to the optical phase modulation means to apply the optical phase modulation to the "lighted phase modulation signal light", and at the same time, from either the optical input / output port a3 or the a4. It is possible to selectively output only "light-illuminated phase-modulated signal light" (see Non-Patent Documents 2 and 3).

Here, more specifically with reference to FIG. 1, in the optical phase modulation means R1-1, the “optical phase modulation control signal light” is the optical signal pulse train Data-1 or the optical signal pulse train CLK-1-out−. It is a DMZ-1, and is input from the optical input port P-R1-1 (corresponding to the optical input / output port a1), and the "lighted phase modulation signal light" is an input optical signal pulse train (secondary optical clock pulse train). CLK-1), which is input from the optical input port (corresponding to the optical input / output port a2) of the optical phase modulation means R1-1 to which the optical waveguide 11R is connected, and the optical phase modulation to which the optical waveguide 12R is connected. Only the input optical signal pulse train (that is, the modulated optical signal pulse train) to which the optical phase modulation is applied is selectively output from the optical output port (corresponding to the optical input / output port a4) of the means R1-1. Further, although not shown in FIG. 1, “optical phase modulation control signal light” (corresponding to the optical input / output port a3) of the optical phase modulation means R1-1 to which nothing is coupled is “optical phase modulation control signal light” (corresponding to the optical input / output port a3). The optical signal pulse train Data-1 or the optical signal pulse train CLK-1-out-DMZ-1) will be output. The optical phase modulation means L1-1 also functions in the same manner.

Further, in the optical phase modulation means R1-2, the "optical phase modulation control signal light" is an optical signal pulse train FF-1, and is input from the optical input port P-R1-2 (corresponding to the optical input / output port a1). The "lighted phase-modulated signal light" is an input light signal pulse train (that is, a modulated light signal pulse train) phase-modulated by the optical phase modulation means R1-1, and is an optical phase modulation to which the optical waveguide 12R is connected. It is input from the optical input port of the means R1-2 (corresponding to the optical input / output port a4), and is connected to the optical waveguide 13R. The optical output port of the optical phase modulation means R1-2 (corresponding to the optical input / output port a2). ), Only the modulated optical signal pulse train to which optical phase modulation is applied will be selectively output. Further, although not shown in FIG. 1, "optical phase modulation control signal light" (corresponding to the optical input / output port a3) of the optical phase modulation means R1-2 to which nothing is coupled is used. The optical signal pulse train FF-1) will be output. The optical phase modulation means L1-2 also functions in the same manner.

Further, in the optical phase modulation means R0 in FIG. 2, the “optical phase modulation control signal light” is the optical signal pulse train ERS-1, and is connected to the optical input port P-R0-1 (corresponding to the optical input / output port a1). The "lighted phase modulation signal light" is an optical clock pulse train CLK-0, and is transmitted from an optical input port (corresponding to the optical input / output port a2) of the optical phase modulation means R0 to which the optical waveguide 51R is connected. Only the optical clock pulse train CLK-0 that has been input and has undergone optical phase modulation is selectively output from the optical output port (corresponding to the optical input / output port a4) of the optical phase modulation means R0 to which the optical waveguide 52R is connected. It will be. Further, although not shown in FIG. 2, "optical phase modulation control signal light" (optical signal) is transmitted from the optical output port (corresponding to the optical input / output port a3) of the optical phase modulation means R0 to which nothing is coupled. The pulse train ERS-1) will be output. The optical phase modulation means L0 also functions in the same manner.

Next, the light receiving unit f1 shown in FIGS. 5 (a) to 7 (b) will be described.

When an optical phase modulation means in which the above-mentioned Mach-Zender interference type optical waveguide circuit configuration is realized by a flat substrate type integrated optical circuit is used, the desired "signal light-control signal light" is used in this optical phase modulation means. In order to perform the "separation operation", it is necessary that the balance of the effective lengths of the two optical interference arms (optical waveguide arms) constituting the interference system with respect to the signal light is precisely adjusted.

However, since various manufacturing errors that cannot be avoided occur when manufacturing this optical waveguide circuit, the effective length is precisely initially adjusted after manufacturing by using the optical phase adjusting units d1 and d2 provided in advance. And it will be balanced.

In the initial adjustment of the effective length of the optical interference arm, for example, when measuring and evaluating the optical output power from the optical input / output ports a3 and a4 while performing the phase adjustment by the optical phase adjusting units d1 and d2, as described above. The optical phase modulation means having a basic circuit configuration has the following problems when the whole is a planar optical circuit.

(1) Since one of the two optical output side ports, the optical input / output ports a3 and a4, the optical input / output port a3 is an empty port to which nothing is connected, the light from the optical input / output port a3. Although it is possible to measure and evaluate the output power, the other optical input / output port a4 of the optical input / output ports a3 and a4 may exist in a closed optical circuit, in which case the optical circuit. It is difficult to take out the optical output to the outside without affecting the loss or the like.
(2) Even if an optical input / output port for taking out an optical output to the outside is provided to the optical input / output port a4 on the premise that the optical circuit will be affected by loss or the like, the optical input / output will be adjusted at the time of phase adjustment. A separate optical coupling system and optical power detector must be provided for the port.

Therefore, as shown in FIGS. 5 (a) to 7 (b), the “optical phase modulation control signal light” (for example, the optical signal pulse train CLK-1-out-DMZ-1) that has undergone light intensity modulation A light receiving unit f1 is provided in the optical input / output port a3 which is an output port. The light receiving unit f1 has a characteristic of receiving signal light output from the optical input / output port a3 and detecting a current corresponding to the light receiving intensity.

The light receiving portion f1 is created as an integrated optical circuit on a compound semiconductor substrate, or a compound optical semiconductor light receiving device is arranged at the relevant location on a quartz-based planar light wave circuit (PLC), or a silicon flat substrate. Created above as an integrated optical circuit.

Since the light output power from the optical input / output port a3 can be measured and evaluated by the light receiving unit f1, the optical coupling system and the optical power detector as described in (2) above become unnecessary, and further, It is possible to perform the initial adjustment of the effective length of the optical interference arm without giving an extra effect such as loss on the optical circuit as described in (1) above, improving the characteristics of the optical circuit and the optical circuit. It is possible to simplify the adjustment of the operating conditions and to improve the economy.

(Configuration of optical branch of optical signal buffer memory circuit)
In the above-mentioned optical signal buffer memory circuit, the optical branching circuits shown in FIGS. 8 to 10 are used as the optical branching portions C-0, C-1, and C-3.

Therefore, the optical branching circuit used as the optical branching portions C-0, C-1, and C-3 will be described with reference to FIGS. 8A to 10C. The optical branch circuit shown in FIGS. 8 (a) to 10 (c) constitutes a Mach-Zehnder interferometer as a whole. In addition, also in FIGS. 8A to 10C, the same reference numerals are given to the same configurations.

In FIGS. 8A to 10C, the multimode interference type waveguide portion bs1 has optical input ports as1 and as2 and optical output ports as5 and as6, and inputs from the optical input ports as1 and as2. It has a function of demultiplexing the generated light at a ratio of light power of 50% each and outputting it from two light output ports as5 and as6.

Further, in FIGS. 8A to 10C, the multimode interference type waveguide portion bs2 has optical input ports as7 and as8 and optical output ports as3 and as4, and optical input ports as7 and as8. It has a function of demultiplexing the light input from the above at a ratio of light power of 50% each and outputting the light from the two optical output ports as3 and as4.

Further, in FIGS. 8A to 10C, the optical output port as5 and the optical input port as7 are connected by the optical waveguide wg1, and the optical output port as6 and the optical input port as8 are connected by the optical waveguide wg2. ing. The optical waveguide wg1 and the optical waveguide wg2 form two left and right optical interference arms, and optical phase adjusting units ds1 and ds2 capable of adjusting the phase of propagating light are arranged on either one or both of them. Has been done.

Specifically, in FIGS. 8 (a), 9 (a), and 10 (a), the optical phase adjusting unit ds1 is arranged in the optical waveguide wg1, and the optical phase adjusting unit ds2 is arranged in the optical waveguide wg2. There is. Further, in FIGS. 8 (b), 9 (b), and 10 (b), the optical phase adjusting unit ds1 is arranged only in the optical waveguide wg1, and the optical phase adjusting unit is not arranged in the optical waveguide wg2. Further, in FIGS. 8 (c), 9 (c), and 10 (c), the optical phase adjusting unit ds2 is arranged only in the optical waveguide wg2, and the optical phase adjusting unit is not arranged in the optical waveguide wg1. As the optical phase adjusting units ds1 and ds2, for example, a type capable of adjusting the amount of optical phase according to the amount of injection current can be adopted.

Further, in FIGS. 9A to 9C, the light source unit es1 is further connected to the optical input port as1 of the multimode interference type waveguide unit bs1. The light source unit es1 can output light having a design drive wavelength of an optical circuit (optical signal buffer memory circuit) by injecting a current.

Further, in FIGS. 10A to 10C, the multimode interference type waveguide section bs0 for optical input is further provided, and the multimode interference type waveguide section bs0 has optical input ports as0 and as11. It also has optical output ports as9 and as10, and the optical output port as10 is connected to the optical input port as1 of the multimode interference type waveguide section bs1. Then, the light source unit es1 is connected to the optical input port as0 of the multimode interference type waveguide unit bs0.

As the optical branching portions C-0, C-1, and C-3, the optical branching portions 100, 110, 120, 200, 210, 220, 300, 310, 320 shown in FIGS. 8 (a) to 10 (c) are used. When adopted, the branch ratio of the optical output power of the light propagating to the optical output ports as3 and as4 is adjusted by adjusting the amount of current injected into both or one of the optical phase adjusting units ds1 and ds2. it can. Therefore, even if the demultiplexing ratio of the multimode interference type waveguides bs1 and bs2 has characteristics different from the design due to manufacturing error or the like, the optical intensity modulation means MZ-0 of the optical signal buffer memory circuit , MZ-1 makes it possible to realize desired light intensity modulation characteristics.

Further, when the optical branching portions 200, 210, 220, 300, 310, 320 shown in FIGS. 9A to 10C are adopted as the optical branching portions C-0, C-1, C-3. Is able to input light for initial adjustment to the optical branching units C-0, C-1, and C-3 simply by injecting a current into the light source unit es1 incorporated in advance and driving the unit. The laser light source for initial adjustment is no longer required, and the optical coupling system for coupling the optical input port of the optical branch and the laser light source for initial adjustment is no longer required. There is no need to adjust the optical coupling of the optical input port of the optical branch.

Further, by providing a light receiving unit (not shown) in the optical circuit of the optical phase modulation means R0, R1-1, R1-2, L0, L1-1, L1-2, the optical output ports as3 and as4 can be used. The output light is received by this light receiving unit, and the initial optical branching adjustment of the optical branching units C-0, C-1, and C-3 can be performed by evaluating the optical power.

(Configuration of modified example of optical signal buffer memory circuit)
In the optical signal buffer memory circuit shown in FIG. 1, the optical output port P-MZ-1-bar, the optical waveguide 14, the optical branching portion C-1, the optical waveguide 15R, and the optical phase modulation means R1-1 are used. , The optical waveguide 12R, the optical phase modulation means R1-2, and the optical waveguide 13R are connected to form a ring-shaped closed light circuit. When the optical waveguide 14 is connected to the optical output port P-MZ-1-cross, the optical output port P-MZ-1-cross, the optical waveguide 14, the optical branching portion C-1, and the optical waveguide 14 are used. The waveguide 15L, the optical phase modulation means L1-1, the optical waveguide 12L, the optical phase modulation means L1-2, and the optical waveguide 13L are connected to form a ring-shaped closed optical circuit.

In the Mach-Zehnder interference type optical phase modulation means R1-1 and L1-1, the balance of the effective lengths of the two optical interference arms (optical waveguide arms) constituting the interference system with respect to the signal light is precisely adjusted. There is a need. However, since various manufacturing errors that cannot be avoided occur when manufacturing an optical waveguide circuit, the effective length is precisely initially adjusted and balanced after manufacturing by using the optical phase adjusting units d1 and d2 provided in advance. Will be taken.

When the optical semiconductor amplifier (SOA) that generates optical gain is used as the optical phase modulation means c1 and c2 inside the optical phase modulation means R1-1 or L1-1 at the time of balance adjustment, the above The ring-shaped closed circuit portion becomes an optical resonator and becomes an oscillation or a state similar to oscillation, and the interference characteristic of this ring-type optical resonator becomes the optical interference characteristic of the optical phase modulation means R1-1 or L1-1. Affect. Therefore, it becomes very difficult to evaluate the optical interference characteristics of the optical phase modulation means R1-1 or L1-1 and adjust the balance.

Therefore, in order to solve such a problem at the time of balance adjustment, in the optical signal buffer memory circuit shown in FIG. 1, the variable light intensity attenuation part VA-1 is located on the input side (optical waveguide 14) of the optical branching part C-1. Or, variable light intensity attenuation portions VA-2 and VA-3 may be provided on the output side (optical waveguides 15L, 15R) of the optical branching portion C-1, respectively, and only at the time of initial balance adjustment. It is designed to give light loss (light intensity attenuation).

With such a configuration, sufficient optical loss (optical attenuation) is imparted to the optical signals input to the optical phase modulation means R1-1 and L1-1 at the time of balance adjustment, whereby the ring It is possible to evaluate the optical interference characteristics of the desired Mach-Zender interference type optical phase modulation means R1-1 and L1-1 and adjust the balance while suppressing the oscillation behavior of the type optical resonator and eliminating this effect. It will be possible.

As such variable light intensity attenuation units VA-1, VA-2, and VA-3, a semiconductor EA modulator in a constant voltage drive state can be adopted. Further, a semiconductor EA modulator in a constant voltage drive state in which the PL (photoluminescence) characteristic of the electric field absorption active layer is set to a shorter wavelength side of 100 nm or more with respect to the set operating wavelength can also be adopted. As a result, when the optical signal buffer memory circuit is used for the original purpose, excessive optical loss is not given, and the ring resonance that hinders the initial adjustment only at the time of the initial adjustment is suppressed. It is possible to give a sufficient light loss to the light loss.

Therefore, in a state where the balance adjustment of the optical phase modulation means R1-1 and L1-1 is completed and adjusted to the desired optical interference conditions, the optical intensity modulation means MZ-1 selectively selects the desired optical signal pulse train. It is possible to output to. Therefore, in the portion of the optical phase modulation means R1-1 and L1-1 in the ring type optical resonator, a large optical loss of 20 dB or more is applied, and the variable optical intensity attenuation portions VA-1 and VA-2 are applied. , VA-3 makes it possible to suppress the oscillation behavior of the ring-type optical resonator even in a state where no optical loss is given.

[Example 2]
The optical circuit of the optical control type optical intensity switch OSW-01 used in the optical signal buffer memory circuit shown in FIG. 1 is not limited to the optical circuit shown in FIG. 2, but the optical circuit shown in FIG. 11 can also be used. .. Therefore, here, another example of the optical circuit of the optical control type optical intensity switch OSW-01 will be described with reference to FIG.

The optical control type optical intensity switch OSW-01-1 shown in FIG. 11 has a flat substrate circuit type multimode optical waveguide WG-M which is an MMI optical interference type optical intensity modulation circuit that functions as an optical gate switch. , This multi-mode optical waveguide WG-M is a flat substrate circuit type single-mode optical waveguide WG-S-In-01, WG-S-In-02, WG-S-Out- for 2x2 input / output. It has 01 and WG-S-Out-02.

The single-mode optical waveguide WG-S-In-01 guides the optical clock pulse train CLK-0 input from the external light input port P-OCLK-In-0 to the multi-mode optical waveguide WG-M, so that external light is emitted. It is connected to the input port P-OCLK-In-0. Further, since the single-mode optical waveguide WG-S-In-02 waveguides the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the multi-mode optical waveguide WG-M, It is connected to the external optical input port P-ERS-In-0. Further, the single-mode optical waveguide WG-S-Out-01 waveguides the secondary optical clock pulse train CLK-1 output from the multi-mode optical waveguide WG-M to the optical output port P-OSW-01-Out. Therefore, it is connected to the optical output port P-OSW-01-Out.

The multimode optical waveguide WG-M is composed of a flat substrate circuit type multimode optical waveguide that causes the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 to interfere with each other. When the optical signal pulse train ERS-1 is not input, the multimode optical waveguide WG-M outputs the optical clock pulse train CLK-0 as the secondary optical clock pulse train CLK-1. On the other hand, when the optical signal pulse train ERS-1 is input, the optical clock pulse train CLK-0 is performed during the time when the optical signal pulse train ERS-1 is input (only during the data length of the optical signal pulse train ERS-1). The optical clock pulse train is removed from the data and output as a secondary optical clock pulse train CLK-1.

As the multi-mode optical waveguide WG-M, there are two single-mode optical waveguides WG-S- in which the optical input from the input side single-mode optical waveguide WG-S-In-01 and WG-S-In-02 is on the output side. Those designed to have 50% optical output coupling to Out-01 and WG-S-Out-02 are used.

With the above configuration, the optical control type optical intensity switch OSW-01-1 has a simple configuration, and the output of the optical clock pulse train CLK-0 or the output of the optical clock pulse train CLK-0 is cut off as a secondary optical clock. It will be output as the pulse train CLK-1. Moreover, since the configuration is simple, reliability can be improved.

[Example 3]
The optical circuit of the optical control type optical intensity switch OSW-01 used in the optical signal buffer memory circuit shown in FIG. 1 is not limited to the optical circuit shown in FIGS. 2 and 11, and the light shown in FIGS. 12 to 13 is used. Circuits can also be used. Therefore, here, another example of the optical circuit of the optical control type optical intensity switch OSW-01 will be described with reference to FIGS. 12 to 13.

The light control type light intensity switch OSW-01-2 shown in FIG. 12 is the same as the light control type light intensity switch OSW-01-1 (see FIG. 11) shown in the second embodiment, and is a multi-mode optical waveguide WG-M. The multi-mode optical waveguide WG-M includes a single-mode optical waveguide WG-S-In-01, WG-S-In-02, WG-S-Out-01, and WG-S-Out-02. are doing.

Then, similarly to the optical control type optical intensity switch OSW-01-1 shown in the second embodiment, the single mode optical waveguide WG-S-In-01 is connected to the external optical input port P-OCLK-In-0. , The single-mode optical waveguide WG-S-Out-01 is connected to the optical output port P-OSW-01-Out.

On the other hand, the single mode optical waveguide WG-S-In-02 is connected to the optical waveguide type phase modulation unit WG-Ph-01, and the optical waveguide type phase modulation unit WG-Ph-01 is a flat substrate circuit type single mode. It is connected to the optical waveguide WG-S-In-03, and the single-mode optical waveguide WG-S-In-03 is connected to the external optical input port P-ERS-In-0.

Here, the optical waveguide type phase modulation unit WG-Ph-01 is an optical waveguide type phase modulation unit for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.

Therefore, the single-mode optical waveguide WG-S-In-03 guides the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type phase modulator WG-Ph-01. The optical waveguide type phase modulator WG-Ph-01 adjusts the phase of the optical signal pulse train ERS-1, and the single-mode optical waveguide WG-S-In-02 adjusts the phase of the optical signal pulse train ERS-1. -1 will be waveguideed to the multimode optical waveguide WG-M.

Further, the optical control type light intensity switch OSW-01-3 shown in FIG. 13 is a modified example of the optical control type light intensity switch OSW-01-2 shown in FIG. 12, and the basic configuration is the same. , The configurations for the single-mode optical waveguide WG-S-In-01 and WG-S-In-02 are different.

Specifically, in the light-controlled light intensity switch OSW-01-3 shown in FIG. 13, the single-mode optical waveguide WG-S is the same as the light-controlled light intensity switch OSW-01-1 shown in the second embodiment. -In-02 is directly connected to the external optical input port P-ERS-In-0, but the single-mode optical waveguide WG-S-In-01 is connected to the optical waveguide type phase modulator WG-Ph-02. The optical waveguide type phase modulator WG-Ph-02 is connected to the flat substrate circuit type single mode optical waveguide WG-S-In-04, and the single mode optical waveguide WG-S-In-04 is externally connected. It is connected to the optical input port P-OCLK-In-0.

Here, the optical waveguide type phase modulation unit WG-Ph-02 is an optical waveguide type phase modulation unit for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.

Therefore, the single-mode optical waveguide WG-S-In-04 guides the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type phase modulator WG-Ph-02. The optical waveguide type phase modulator WG-Ph-02 adjusts the phase of the optical clock pulse train CLK-0, and the single-mode optical waveguide WG-S-In-01 adjusts the phase of the optical clock pulse train CLK. −0 will be waveguideed to the multimode optical waveguide WG-M.

In the above-mentioned optical waveguide type phase modulators WG-Ph-01 and WG-Ph-02, the optical clock pulse train CLK-0 is performed at the input stage to the optical control type optical intensity switches OSW-01-2 and OSW-01-3. When the optical signal pulse train ERS-1 and the optical signal pulse train ERS-1 are not adjusted to have a phase relationship in which they interfere with each other in a subtractive manner in the multimode optical waveguide WG-M, the phase relationship is adjusted so as to interfere with each other in a subtractive manner. Can be done.

With the above configuration, the optical control type optical intensity switches OSW-01-2 and OSW-01-3 have a simple configuration, and the output of the optical clock pulse train CLK-0 or the output of the optical clock pulse train CLK-0 is cut off. Will be output as a secondary optical clock pulse train CLK-1. Moreover, since the configuration is simple, reliability can be improved. Further, since the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 is adjusted, the optical clock from the optical clock pulse train CLK-0 only during the data length of the input optical signal pulse train ERS-1. The pulse train can be reliably removed.

[Example 4]
The optical circuit of the optical control type optical intensity switch OSW-01 used in the optical signal buffer memory circuit shown in FIG. 1 is not limited to the optical circuits shown in FIGS. 2 and 11 to 13, but FIGS. 14 to 17 The optical circuit shown in is also available. Therefore, here, another example of the optical circuit of the optical control type optical intensity switch OSW-01 will be described with reference to FIGS. 14 to 17.

The optical control type light intensity switch OSW-01-4 shown in FIG. 14 includes the optical control type light intensity switch OSW-01-1 (see FIG. 11) shown in Example 2 and the optical control type light shown in Example 3. Similar to the intensity switches OSW-01-2 (see FIG. 12) and OSW-01-3 (see FIG. 13), the multimode optical waveguide WG-M has a multimode optical waveguide WG-M, and the multimode optical waveguide WG-M is a single mode optical waveguide. It has a waveguide WG-S-In-01, WG-S-In-02, WG-S-Out-01, and WG-S-Out-02.

Then, similarly to the light control type light intensity switch OSW-01-1 shown in Example 2 and the light control type light intensity switch OSW-01-2 shown in Example 3, the single mode optical waveguide WG-S-In -01 is connected to the external optical input port P-OCLK-In-0, and the single-mode optical waveguide WG-S-Out-01 is connected to the optical output port P-OSW-01-Out.

Further, similarly to the optical control type optical intensity switch OSW-01-2 shown in the third embodiment, the single mode optical waveguide WG-S-In-02 is connected to the optical waveguide type phase modulation unit WG-Ph-01. , The external optical input port P-ERS-In-0 is connected to the single-mode optical waveguide WG-S-In-03, but in this embodiment, the single-mode optical waveguide WG-S-In-03 is It is connected to the optical waveguide type intensity attenuation unit WG-Att-01, and a flat substrate circuit type single is connected between the optical waveguide type intensity attenuation unit WG-Att-01 and the optical waveguide type phase modulation unit WG-Ph-01. Mode Optical Waveguide WG-S-In-05 is connected.

Here, since the optical waveguide type phase modulation unit WG-Ph-01 is the same as that described in the third embodiment, the same reference numerals are given here, and the description thereof will be omitted. Further, the optical waveguide type intensity attenuation unit WG-Att-01 is an optical waveguide type intensity attenuation unit provided to adjust the optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 to the same intensity. ..

Therefore, the single-mode optical waveguide WG-S-In-03 guides the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type intensity attenuation unit WG-Att-01. The optical waveguide type intensity attenuation unit WG-Att-01 attenuates and adjusts the light intensity of the optical signal pulse train ERS-1, and the single-mode optical waveguide WG-S-In-05 attenuates and adjusts the light intensity. The signal pulse train ERS-1 is waveguideed to the optical waveguide type phase modulator WG-Ph-01, and the optical waveguide type phase modulator WG-Ph-01 adjusts the phase of the optical waveguide type phase modulation unit WG-Ph-01, and the single mode optical waveguide The WG-S-In-02 will attenuate the phase-adjusted optical signal pulse train ERS-1 to the multimode optical waveguide WG-M.

Further, the optical control type light intensity switches OSW-01-5, OSW-01-6, and OSW-01-7 shown in FIGS. 15 to 17 are the light control type light intensity switches OSW-01-4 shown in FIG. The basic configuration is the same, but the configurations for the single-mode optical waveguides WG-S-In-01 and WG-S-In-02 are different.

Specifically, in the optical control type optical intensity switch OSW-01-5 shown in FIG. 15, the single mode optical waveguide WG-S-In-01 is connected to the optical waveguide type intensity attenuation unit WG-Att-02. The optical waveguide type intensity attenuation unit WG-Att-02 is connected to the single mode optical waveguide WG-S-In-04, and the single mode optical waveguide WG-S-In-04 is connected to the external optical input port P-OCLK-In. It is connected to −0. Further, the single mode optical waveguide WG-S-In-02 is connected to the optical waveguide type phase modulation unit WG-Ph-01, and the optical waveguide type phase modulation unit WG-Ph-01 is connected to the single mode optical waveguide WG-S. -In-03 is connected, and the single-mode optical waveguide WG-S-In-03 is connected to the external optical input port P-ERS-In-0.

Here, since the optical waveguide type phase modulation unit WG-Ph-01 is the same as that described in the third embodiment, the same reference numerals are given here, and the description thereof will be omitted. Further, the optical waveguide type intensity attenuation unit WG-Att-02 is an optical waveguide type intensity attenuation unit provided to adjust the optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 to the same intensity. ..

Therefore, the single-mode optical waveguide WG-S-In-04 guides the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type intensity attenuation unit WG-Att-02. The wave-guided optical waveguide type intensity attenuation unit WG-Att-02 attenuated and adjusted the light intensity of the optical clock pulse train CLK-0, and the single mode optical waveguide WG-S-In-01 attenuated and adjusted the light intensity. The optical clock pulse train CLK-0 will be attenuated to the multimode optical waveguide WG-M. Further, the single-mode optical waveguide WG-S-In-03 guides the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type phase modulator WG-Ph-01. The optical waveguide type phase modulator WG-Ph-01 adjusts the phase of the optical signal pulse train ERS-1, and the single-mode optical waveguide WG-S-In-02 adjusts the phase of the optical signal pulse train ERS-1. -1 will be waveguideed to the multimode optical waveguide WG-M.

Further, in the optical control type optical intensity switch OSW-01-6 shown in FIG. 16, the single mode optical waveguide WG-S-In-01 is connected to the optical waveguide type phase modulator WG-Ph-02 to form an optical waveguide type. The phase modulator WG-Ph-02 is connected to the single-mode optical waveguide WG-S-In-04, and the single-mode optical waveguide WG-S-In-04 is connected to the external optical input port P-OCLK-In-0. It is connected. Further, the single mode optical waveguide WG-S-In-02 is connected to the optical waveguide type intensity attenuation unit WG-Att-01, and the optical waveguide type intensity attenuation unit WG-Att-01 is connected to the single mode optical waveguide WG-S. -In-03 is connected, and the single-mode optical waveguide WG-S-In-03 is connected to the external optical input port P-ERS-In-0.

Here, the optical waveguide type phase modulation unit WG-Ph-02 is the same as that described in the third embodiment, and the optical waveguide type intensity attenuation unit WG-Att-01 is a diagram of the present embodiment. Since it is the same as that described in No. 14, the same reference numerals are given here, and the description thereof will be omitted.

Therefore, the single-mode optical waveguide WG-S-In-04 guides the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type phase modulator WG-Ph-02. The optical waveguide type phase modulator WG-Ph-02 adjusts the phase of the optical clock pulse train CLK-0, and the single-mode optical waveguide WG-S-In-01 adjusts the phase of the optical clock pulse train CLK. −0 will be waveguideed to the multimode optical waveguide WG-M. Further, the single-mode optical waveguide WG-S-In-03 guides the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type intensity attenuation unit WG-Att-01. The wave-guided optical waveguide type intensity attenuation unit WG-Att-01 attenuated and adjusted the light intensity of the optical signal pulse train ERS-1, and the single mode optical waveguide WG-S-In-02 attenuated and adjusted the light intensity. The optical signal pulse train ERS-1 will be guided to the multimode optical waveguide WG-M.

Further, in the optical control type optical intensity switch OSW-01-7 shown in FIG. 17, the single-mode optical waveguide WG-S-In-02 is directly connected to the external optical input port P-ERS-In-0. , The single-mode optical waveguide WG-S-In-01 is connected to the optical waveguide type phase modulator WG-Ph-02, and the external optical input port P-OCLK-In-0 is the single-mode optical waveguide WG-S-. Connected to In-04, the single-mode optical waveguide WG-S-In-04 is connected to the optical waveguide type intensity attenuation section WG-Att-02, and the optical waveguide type intensity attenuation section WG-Att-02 and optical waveguide are connected. A flat substrate circuit type single-mode optical waveguide WG-S-In-06 is connected to the waveguide type phase modulation unit WG-Ph-02.

Here, the optical waveguide type phase modulation unit WG-Ph-02 is the same as that described in the third embodiment, and the optical waveguide type intensity attenuation unit WG-Att-02 is a diagram of the present embodiment. Since it is the same as that described in No. 15, the same reference numerals are given here, and the description thereof will be omitted.

Therefore, the single-mode optical waveguide WG-S-In-04 guides the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type intensity attenuation unit WG-Att-02. The wave-guided optical waveguide type intensity attenuation unit WG-Att-02 attenuated and adjusted the light intensity of the optical clock pulse train CLK-0, and the single mode optical waveguide WG-S-In-06 attenuated and adjusted the light intensity. The optical clock pulse train CLK-0 is waveguideed to the optical waveguide type phase modulator WG-Ph-02, and the optical waveguide type phase modulator WG-Ph-02 adjusts the phase of the optical waveguide type phase modulator WG-Ph-02 in a single mode. The optical waveguide WG-S-In-01 attenuates the phase-adjusted optical clock pulse train CLK-0 to the multimode optical waveguide WG-M.

In the above-mentioned optical waveguide type phase modulators WG-Ph-01 and WG-Ph-02, the optical control type optical intensity switches OSW-01-4, OSW-01-5, OSW-01-6, OSW-01-7 When the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 are not adjusted to have a phase relationship in which they interfere with each other in a subtractive manner in the multimode optical waveguide WG-M at the input stage to, they are subtractive from each other. It can be adjusted so that the phase relationship interferes with.

In addition, in the above-mentioned optical waveguide type intensity attenuation units WG-Att-01 and WG-Att-02, the optical control type optical intensity switches OSW-01-4, OSW-01-5, OSW-01-6, OSW- When the optical intensity is not adjusted to be the same so that the optical clock pulse train CLK-0 is turned off in the multimode optical waveguide WG-M by the optical signal pulse train ERS-1 at the input stage to 01-7. The light intensity can be adjusted to the same level.

With the above-described configuration, the optical control type optical intensity switches OSW-01-4, OSW-01-5, OSW-01-6, and OSW-01-7 have a simple configuration and can output the optical clock pulse train CLK-0 or. The output obtained by cutting the output of the optical clock pulse train CLK-0 is output as the secondary optical clock pulse train CLK-1. Moreover, since the configuration is simple, reliability can be improved. Further, the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 is adjusted, and the light intensity of the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 is adjusted to the same level. The optical clock pulse train can be reliably removed from the optical clock pulse train CLK-0 only during the data length of the optical signal pulse train ERS-1.

The present invention is applicable to optical communication, optical processing, optical signal buffer memory circuits in optical computers, and optical signal buffering methods.

MZ-1: Mach-Zender interference type optical intensity modulation means P-OCLK-In: Optical input port of secondary optical clock pulse train P-MZ-1-bar: Located on the bar side with respect to P-OCLK-In Optical output port P-MZ-1-cross: Optical output port located on the cross side with respect to P-OCLK-In

OSW-01: Optical control type optical intensity switch P-OCLK-In-0: External optical input port for optical clock pulse train input P-ERS-In-0: External optical input port for optical signal pulse train input for storage information erasure control P-OSW-01-Out: Optical output port

MZ-0: Mach-Zehnder interference type optical intensity modulation means P-MZ-0-bar: Optical output port P-MZ-0-cross: P-OCLK located on the bar side with respect to P-OCLK-In-0. Optical output port located on the cross side with respect to −In-0

R0: Optical phase modulation means P-R0-1: Optical phase modulation control signal to optical phase modulation means R0 Optical input port L0: Optical phase modulation means P-L0-1: Optical phase to optical phase modulation means L0 Optical input port for modulation control signal light

R1-1: Optical phase modulation means P-R1-1: Optical phase modulation control signal to optical phase modulation means R1-1 Optical input port of light L1-11: Optical phase modulation means P-L1-1: Optical phase modulation Optical phase modulation control signal to means L1-1 Optical input port of light

R1-2: Optical phase modulation means P-R1-2: Optical phase modulation control signal to optical phase modulation means R1-2 Optical input port L1-2: Optical phase modulation means P-L1-2: Optical phase modulation Optical phase modulation control signal to means L1-2 Optical input port of light

C-0: Optical branching part (optical branching means)
PC0-1: Optical input port PC0-2: Optical input port PC0-3: Optical output port PC0-4: Optical output port

C-1: Optical branching part (optical branching means)
PC1-1: Optical input port PC1-2: Optical input port PC1-3: Optical output port PC1-4: Optical output port

C-3: Optical branching part (optical branching means)
PC3-1: Optical input port PC3-2: Optical input port PC3-3: Optical output port PC3-4: Optical output port

P-Data-In: External optical input port for optical signal pulse train input for data P-FF-In: External optical input port for optical signal pulse train input for flip-flop control

DD-0: Optical propagation delay difference imparting unit (optical propagation delay difference imparting means)
D-D-1: Light propagation delay difference imparting unit (light propagation delay difference imparting means)
D-D-2: Light propagation delay difference imparting unit (light propagation delay difference imparting means)

VA-1 to V-3: Variable light intensity attenuator

P-OP-In: Optical input port P-OP-Out: Optical output port OS-1: 1 × N Optical switch ODL-1 to ODL-N: Optical delay line O-Loop: Optical waveguide loop OA: Optical amplifier OS -2: 2 x 2 optical switch

WG-M Multimode Optical Waveguide WG-Ph-01, WG-Ph-02 Optical Waveguide Phase Modulator WG-Att-01, WG-Att-02 Optical Waveguide Intensity Attenuator

Claims (13)

In an optical signal buffer memory circuit that holds a data pattern in the circuit
The external optical input port P-OCLK-In-0 for inputting the optical clock pulse train CLK-0 output from the clock signal light source and the erasing control for erasing the data pattern held in the circuit. The optical clock pulse train CLK-0 is output or the optical clock pulse train is output as the external optical input port P-ERS-In-0 for inputting the optical signal pulse train ERS-1 and the secondary optical clock pulse train CLK-1. An optical control type optical intensity switch OSW-01 having an optical output port P-OSW-01-Out that cuts and outputs the output of CLK-0, and
An optical waveguide 53 that guides the secondary optical clock pulse train CLK-1 output from the optical output port P-OSW-01-Out, and
An optical input port P-OCLK-In connected to the optical waveguide 53 to input the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out, and the optical input port. Two first optical interference arms having an optical output port P-MZ-1-bar located on the bar side and an optical output port P-MZ-1-cross located on the cross side with respect to P-OCLK-In. And the optical phase modulation means L1-1 located on the optical waveguide of one of the first optical interference arms and for modulating the phase of the optical signal pulse train propagating in the first optical interference arm. It is located on the optical waveguide of the other first optical interference arm, and has an optical phase modulation means R1-1 for modulating the phase of the optical signal pulse train propagating in the first optical interference arm. , Mach-Zenda interference-type light intensity modulation means MZ-1 that functions as a Mach-Zenda-type interferometer,
An optical waveguide 18 that is connected to an external optical input port P-Data-In for inputting an optical signal pulse train Data-1 having information on the data pattern and guides the optical signal pulse train Data-1.
An optical input port PC1-1 connected to the optical waveguide 18 to which the optical signal pulse train Data-1 from the external optical input port P-Data-In is input, and an optical output port P-MZ-1- Optical input ports PC1-2 and optical output ports PC1-3 and PC1-4 to which optical signal pulse trains from either bar or the optical output port P-MZ-1-cross are input. Optical branch for branching and outputting the optical signal pulse train input from the optical input ports P-C1-2 and P-C1-1 to the optical output ports P-C1-3 and P-C1-4. Part C-1 and
An optical waveguide 14 that guides an optical signal pulse train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-C1-2.
Light from the optical output port PC1-3 connected to the optical input port PL1-1 for inputting the optical signal pulse train for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L that guides a signal pulse train and
Light from the optical output port PC1-4 connected to the optical input port P-R1-1 for inputting the optical signal pulse train for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R that guides a signal pulse train,
Optical signal pulse trains provided on the optical waveguide 15L or the optical waveguide 15R and simultaneously output from the optical output ports P-C1-3 and P-C1-4 are the optical input ports P-L1-1 and P-. An optical waveguide portion D-D-1 that produces an optical delay for adjusting the timing of reaching R1-1 so as to be equal to or greater than the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period.
With
As the optical clock pulse train CLK-0, an RZ (Return to Zero) type optical signal pulse train continues to be input from the external optical input port P-OCLK-In-0.
The optical signal pulse train ERS-1 is synchronized with the clock of the optical clock pulse train CLK-0, synchronized with the period of the data pattern, and has the same length as the data length of the data pattern. Signal pulse train
After holding the data pattern in the circuit, when the optical signal pulse train ERS-1 is input from the external optical input port P-ERS-In-0, the data length of the optical signal pulse train ERS-1 is reached. However, the output of the optical clock pulse train CLK-0 is cut to obtain the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out to the optical input port P-OCLK-In. Output and
In the Mach-Zender interference type optical intensity modulation means MZ-1, the optical output port P is provided by the secondary optical clock pulse train CLK-1 which is input from the optical input port P-OCLK-In and whose output is cut. An optical signal buffer memory circuit characterized by creating a state in which no optical signal pulse train is output from −MZ-1-bar and P-MZ-1-cross, canceling the holding state of the data pattern, and returning to the initial state. .. In the optical signal buffer memory circuit according to claim 1,
The light control type light intensity switch OSW-01 is
It is located on the external optical input port P-OCLK-In-0 and the optical output ports P-MZ-0-bar and cross side located on the bar side with respect to the external optical input port P-OCLK-In-0. It is located on the optical waveguide of two second optical interference arms having an optical output port P-MZ-0-cross and one of the second optical interference arms, and propagates in the second optical interference arm. An optical phase modulation means L0 for modulating the phase of the optical signal pulse train, and an optical signal pulse train located on the optical waveguide of the other second optical interference arm and propagating in the second optical interference arm. Mach-Zenda interference-type optical intensity modulation means MZ-0, which has an optical phase-modulating means R0 for imparting modulation to the phase of the light, and functions as a Mach-Zender-type interferator.
An optical waveguide 55 that guides the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0, and
Optical input port PC0-1 and optical output port PC0-3 connected to the optical waveguide 55 to which the optical signal pulse train ERS-1 from the external optical input port P-ERS-In-0 is input. , P-C0-4, and the optical signal pulse train ERS-1 input from the optical input port P-C0-1 is branched and output to the optical output ports P-C0-3 and P-C0-4. Optical branch C-0 to make it
An optical signal pulse train from the optical output port PC0-3 connected to an optical input port P-L0-1 for inputting an optical signal pulse train for inducing an optical phase modulation action to the optical phase modulation means L0. Optical waveguide 54L that guides
An optical signal pulse train from the optical output port PC0-4 connected to an optical input port P-R0-1 for inputting an optical signal pulse train for inducing an optical phase modulation action to the optical phase modulation means R0. Optical waveguide 54R that guides
Optical signal pulse trains provided on the optical waveguide 54L or the optical waveguide 54R and simultaneously output from the optical output ports P-C0-3 and P-C0-4 are the optical input ports P-L0-1 and P-. An optical waveguide portion DD-0 that produces an optical delay for adjusting the timing of reaching R0-1 so as to be equal to or greater than the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period.
With
Either the optical output port P-MZ-0-bar or the optical output port P-MZ-0-clock is set as the optical output port P-OSW-01-Out, and the optical signal pulse train ERS-1 is input. When not, the optical clock pulse train CLK-0 is output as the secondary optical clock pulse train CLK-1, and when the optical signal pulse train ERS-1 is input, the data length of the optical signal pulse train ERS-1 is increased. An optical signal buffer memory circuit characterized in that the output of the optical clock pulse train CLK-0 is cut for a short time and output as the secondary optical clock pulse train CLK-1. In the optical signal buffer memory circuit according to claim 2.
When the optical signal pulse train ERS-1 is input from the external optical input port P-ERS-In-0, the input optical signal pulse train ERS-1 is used to drive the optical phase modulation means R0 and L0. Then, the phase of the optical clock pulse train CLK-0 propagating in the two second optical interference arms of the Mach-Zender interference type light intensity modulation means MZ-0 is π-modulated to π-modulate the optical signal pulse train. The output of the optical clock pulse train CLK-0 is cut only during the data length of the ERS-1 to obtain the secondary optical clock pulse train CLK-1, which is the light from the optical output port P-OSW-01-Out. An optical signal buffer memory circuit characterized by outputting to an input port P-OCLK-In. In the optical signal buffer memory circuit according to claim 1,
The light control type light intensity switch OSW-01 is
The optical is composed of a flat substrate circuit type multi-mode optical waveguide that interferes with the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1, and the light is input only during the data length of the optical signal pulse train ERS-1. A multi-mode optical waveguide WG-M that removes the optical clock pulse train from the clock pulse train CLK-0 and outputs it as the secondary optical clock pulse train CLK-1.
A flat substrate circuit type single-mode optical waveguide WG-S for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the multi-mode optical waveguide WG-M. -In-01 and
A flat substrate circuit type single-mode optical waveguide WG-S for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the multi-mode optical waveguide WG-M. −In-02 and
A flat substrate circuit type single-mode optical waveguide WG-S- for guiding the secondary optical clock pulse train CLK-1 from the multi-mode optical waveguide WG-M to the optical output port P-OSW-01-Out. Out-01 and
An optical signal buffer memory circuit comprising. In the optical signal buffer memory circuit according to claim 4,
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-01 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
A flat substrate circuit type single-mode optical beam for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type phase modulator WG-Ph-01. Waveguide WG-S-In-03 and
With
The single-mode optical waveguide WG-S-In-02 guides the optical signal pulse train ERS-1 whose phase has been adjusted in the optical waveguide type phase modulator WG-Ph-01 to the multi-mode optical waveguide WG-M. An optical signal buffer memory circuit characterized by waving. In the optical signal buffer memory circuit according to claim 4,
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-02 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
A flat board circuit type single-mode optical beam for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type phase modulator WG-Ph-02. Waveguide WG-S-In-04 and
With
The single-mode optical waveguide WG-S-In-01 guides the phase-adjusted optical clock pulse train CLK-0 in the optical waveguide type phase modulator WG-Ph-02 to the multi-mode optical waveguide WG-M. An optical signal buffer memory circuit characterized by a wave. In the optical signal buffer memory circuit according to claim 4,
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-01 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
An optical waveguide type intensity attenuation unit WG-Att-01 for adjusting the relative optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 by attenuating the optical signal pulse train ERS-1.
A flat substrate circuit type single-mode optical beam for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type intensity attenuation unit WG-Att-01. Waveguide WG-S-In-03 and
Flat substrate circuit type single-mode optical waveguide WG-S-In-05 for waveguideing between the optical waveguide type intensity attenuation unit WG-Att-01 and the optical waveguide type phase modulation unit WG-Ph-01. When,
With
The single-mode optical waveguide WG-S-In-02 guides the optical signal pulse train ERS-1 whose phase has been adjusted in the optical waveguide type phase modulator WG-Ph-01 to the multi-mode optical waveguide WG-M. An optical signal buffer memory circuit characterized by waving. In the optical signal buffer memory circuit according to claim 4,
The light control type light intensity switch OSW-01 is
An optical waveguide type intensity attenuation unit WG-Att-02 for adjusting the relative optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 by attenuating the optical clock pulse train CLK-0.
A flat board circuit type single-mode optical beam for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type intensity attenuation unit WG-Att-02. Waveguide WG-S-In-04 and
An optical waveguide type phase modulator WG-Ph-01 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
A flat substrate circuit type single-mode optical beam for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type phase modulator WG-Ph-01. Waveguide WG-S-In-03 and
With
The single-mode optical waveguide WG-S-In-01 uses the optical clock pulse train CLK-0 whose light intensity is attenuated and adjusted in the optical waveguide type intensity attenuation unit WG-Att-02 to the multimode optical waveguide WG-M. Waveguided to
The single-mode optical waveguide WG-S-In-02 guides the optical signal pulse train ERS-1 whose phase has been adjusted in the optical waveguide type phase modulator WG-Ph-01 to the multi-mode optical waveguide WG-M. An optical signal buffer memory circuit characterized by waving. In the optical signal buffer memory circuit according to claim 4,
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-02 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
A flat board circuit type single-mode optical beam for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type phase modulator WG-Ph-02. Waveguide WG-S-In-04 and
An optical waveguide type intensity attenuation unit WG-Att-01 for adjusting the relative optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 by attenuating the optical signal pulse train ERS-1.
A flat substrate circuit type single-mode optical beam for waveguideing the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0 to the optical waveguide type intensity attenuation unit WG-Att-01. Waveguide WG-S-In-03 and
With
The single-mode optical waveguide WG-S-In-01 guides the phase-adjusted optical clock pulse train CLK-0 in the optical waveguide type phase modulator WG-Ph-02 to the multi-mode optical waveguide WG-M. Wave,
The single-mode optical waveguide WG-S-In-02 uses the optical signal pulse train ERS-1 whose light intensity is attenuated and adjusted in the optical waveguide type intensity attenuation unit WG-Att-01 to the multi-mode optical waveguide WG-M. An optical signal buffer memory circuit characterized by waveguideing to. In the optical signal buffer memory circuit according to claim 4,
The light control type light intensity switch OSW-01 is
An optical waveguide type phase modulator WG-Ph-02 for adjusting the relative optical phase relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1.
An optical waveguide type intensity attenuation unit WG-Att-02 for adjusting the relative optical intensity relationship between the optical clock pulse train CLK-0 and the optical signal pulse train ERS-1 by attenuating the optical clock pulse train CLK-0.
A flat board circuit type single-mode optical beam for waveguideing the optical clock pulse train CLK-0 input from the external optical input port P-OCLK-In-0 to the optical waveguide type intensity attenuation unit WG-Att-02. Waveguide WG-S-In-04 and
Flat substrate circuit type single-mode optical waveguide WG-S-In-06 for waveguideing between the optical waveguide type intensity attenuation unit WG-Att-02 and the optical waveguide type phase modulation unit WG-Ph-02. When,
With
The single-mode optical waveguide WG-S-In-01 guides the phase-adjusted optical clock pulse train CLK-0 in the optical waveguide type phase modulator WG-Ph-02 to the multi-mode optical waveguide WG-M. An optical signal buffer memory circuit characterized by a wave. As an optical signal buffer memory circuit that holds a data pattern in the circuit
The external optical input port P-OCLK-In-0 for inputting the optical clock pulse train CLK-0 output from the clock signal light source and the erasing control for erasing the data pattern held in the circuit. The optical clock pulse train CLK-0 is output or the optical clock pulse train is output as the external optical input port P-ERS-In-0 for inputting the optical signal pulse train ERS-1 and the secondary optical clock pulse train CLK-1. An optical control type optical intensity switch OSW-01 having an optical output port P-OSW-01-Out that cuts and outputs the output of CLK-0, and
An optical waveguide 53 that guides the secondary optical clock pulse train CLK-1 output from the optical output port P-OSW-01-Out, and
Optical input port P-OCLK-In connected to the optical waveguide 53 to input the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out.
And two optical output ports P-MZ-1-bar located on the bar side and optical output port P-MZ-1-cross located on the cross side with respect to the optical input port P-OCLK-In. Optical phase modulation located on the optical waveguide of the first optical interference arm and one of the first optical interference arms to modulate the phase of an optical signal pulse train propagating in the first optical interference arm. Optical phase modulation means R1 located on the optical waveguide of the means L1-1 and the other first optical interference arm and for modulating the phase of the optical signal pulse train propagating in the first optical interference arm. Mach-Zender interference type light intensity modulation means MZ-1, which has -1 and functions as a Mach-Zender type interferometer, and
An optical waveguide 18 that is connected to an external optical input port P-Data-In for inputting an optical signal pulse train Data-1 having information on the data pattern and guides the optical signal pulse train Data-1.
An optical input port PC1-1 connected to the optical waveguide 18 to which the optical signal pulse train Data-1 from the external optical input port P-Data-In is input, and an optical output port P-MZ-1- Optical input ports PC1-2 and optical output ports PC1-3 and PC1-4 to which optical signal pulse trains from either bar or the optical output port P-MZ-1-cross are input. Optical branch for branching and outputting the optical signal pulse train input from the optical input ports P-C1-2 and P-C1-1 to the optical output ports P-C1-3 and P-C1-4. Part C-1 and
An optical waveguide 14 that guides an optical signal pulse train from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross to the optical input port P-C1-2.
Light from the optical output port PC1-3 connected to the optical input port PL1-1 for inputting the optical signal pulse train for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L that guides a signal pulse train and
Light from the optical output port PC1-4 connected to the optical input port P-R1-1 for inputting the optical signal pulse train for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R that guides a signal pulse train,
Optical signal pulse trains provided on the optical waveguide 15L or the optical waveguide 15R and simultaneously output from the optical output ports P-C1-3 and P-C1-4 are the optical input ports P-L1-1 and P-. An optical waveguide portion D-D-1 that produces an optical delay for adjusting the timing of reaching R1-1 so as to be equal to or greater than the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period.
In the optical signal buffer method using the circuit,
As the optical clock pulse train CLK-0, an RZ (Return to Zero) type optical signal pulse train is continuously input from the external optical input port P-OCLK-In-0.
The optical signal pulse train ERS-1 is synchronized with the clock of the optical clock pulse train CLK-0, synchronized with the period of the data pattern, and has the same length as the data length of the data pattern. Signal pulse train
After holding the data pattern in the circuit, the optical signal pulse train ERS-1 is input from the external optical input port P-ERS-In-0, and only during the data length of the optical signal pulse train ERS-1. The output of the optical clock pulse train CLK-0 is cut and output as the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out to the optical input port P-OCLK-In. ,
In the Mach-Zender interference type optical intensity modulation means MZ-1, the optical output port P is provided by the secondary optical clock pulse train CLK-1 which is input from the optical input port P-OCLK-In and whose output is cut. An optical signal buffer method comprising creating a state in which an optical signal pulse train is not output from −MZ-1-bar and P—MZ-1-cross, canceling the holding state of the data pattern, and returning to the initial state. In the optical signal buffer method according to claim 11,
As the light control type light intensity switch OSW-01,
It is located on the external optical input port P-OCLK-In-0 and the optical output ports P-MZ-0-bar and cross side located on the bar side with respect to the external optical input port P-OCLK-In-0. It is located on the optical waveguide of two second optical interference arms having an optical output port P-MZ-0-cross and one of the second optical interference arms, and propagates in the second optical interference arm. An optical phase modulation means L0 for modulating the phase of the optical signal pulse train, and an optical signal pulse train located on the optical waveguide of the other second optical interference arm and propagating in the second optical interference arm. Mach-Zenda interference-type optical intensity modulation means MZ-0, which has an optical phase-modulating means R0 for imparting modulation to the phase of the light, and functions as a Mach-Zender-type interferator.
An optical waveguide 55 that guides the optical signal pulse train ERS-1 input from the external optical input port P-ERS-In-0, and
Optical input port PC0-1 and optical output port PC0-3 connected to the optical waveguide 55 to which the optical signal pulse train ERS-1 from the external optical input port P-ERS-In-0 is input. , P-C0-4, and the optical signal pulse train ERS-1 input from the optical input port P-C0-1 is branched and output to the optical output ports P-C0-3 and P-C0-4. Optical branch C-0 to make it
An optical signal pulse train from the optical output port PC0-3 connected to an optical input port P-L0-1 for inputting an optical signal pulse train for inducing an optical phase modulation action to the optical phase modulation means L0. Optical waveguide 54L that guides
An optical signal pulse train from the optical output port PC0-4 connected to an optical input port P-R0-1 for inputting an optical signal pulse train for inducing an optical phase modulation action to the optical phase modulation means R0. Optical waveguide 54R that guides
Optical signal pulse trains provided on the optical waveguide 54L or the optical waveguide 54R and simultaneously output from the optical output ports P-C0-3 and P-C0-4 are the optical input ports P-L0-1 and P-. An optical waveguide portion DD-0 that produces an optical delay for adjusting the timing of reaching R0-1 so as to be equal to or greater than the pulse width of the optical clock pulse train CLK-0 and less than the pulse repetition period.
With
Either the optical output port P-MZ-0-bar or the optical output port P-MZ-0-clock is set as the optical output port P-OSW-01-Out, and the optical signal pulse train ERS-1 is not input. When the optical clock pulse train CLK-0 is output as the secondary optical clock pulse train CLK-1 and the optical signal pulse train ERS-1 is input, only during the data length of the optical signal pulse train ERS-1. An optical signal buffer method comprising cutting the output of the optical clock pulse train CLK-0 and outputting it as the secondary optical clock pulse train CLK-1. In the optical signal buffer method according to claim 12,
The optical signal pulse train ERS-1 is input from the external optical input port P-ERS-In-0, and the optical phase modulation means R0 and L0 are driven by using the input optical signal pulse train ERS-1. , The phase of the optical clock pulse train CLK-0 propagating in the two second optical interference arms of the Mach-Zender interference type light intensity modulation means MZ-0 is π-modulated, and the optical signal pulse train ERS- The output of the optical clock pulse train CLK-0 is cut only during the data length of 1, and the optical clock pulse train CLK-1 is used as the secondary optical clock pulse train CLK-1 from the optical output port P-OSW-01-Out to the optical input port. An optical signal buffering method characterized by outputting to P-OCLK-In.

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