JP5944848B2 - Optical signal buffer memory circuit - Google Patents

Description

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

  As typical methods for realizing the optical signal buffer, the following methods have been proposed.

[First prior art]
In the first method, as shown in FIG. 7, a plurality of optical delay optical waveguides ODL-1 to ODL-N having different lengths are prepared, and the optical delay optical waveguides ODL-1 to ODL-N are prepared. An optical switch OS-1 is disposed at the input end, and an optical multiplexer OC-1 is disposed at the output end. An optical signal input from the input port P-OP-In is optically delayed as a propagation path using the optical switch OS-1. By switching between the optical waveguides ODL-1 to ODL-N, a function as a buffer memory is realized by a method of giving a desired optical delay and outputting from the output port P-OP-Out.

  In this first method, delays other than the optical delay optical waveguides ODL-1 to ODL-N prepared in advance cannot be applied, and the optical switch OS-1 can be used for switching. Because there is a limit to the number of optical propagation paths (the current commercial product is about tens of times, and there is another problem that the insertion optical loss increases as the switchable number increases). Only an extremely limited optical buffer memory can be realized with respect to the storage time of the column, and as the pattern of the switchable optical delay amount increases, the optical circuit becomes larger.

[Second prior art]
The second method uses an optical circuit as shown in FIG. 8 to store a stored optical data signal string input from an input port P-OP-In in a fiber loop or an optical waveguide loop O-Loop. A desired optical delay is obtained by rotating the optical amplifier OA while performing propagation loss compensation and the like, extracting it as an optical data signal sequence at a desired timing by the optical switch OS-2, and outputting it from the output port P-OP-Out. To realize the function as an optical buffer memory.

  This method was devised in the hope that it can overcome the problem of the first method, “As the pattern of switchable optical delay amount increases, the optical circuit becomes larger.” In this second method, as the number of times the optical data signal train is circulated increases, the propagation loss of the optical waveguide loop O-Loop for circulation is compensated. The optical waveform of the optical data signal train gradually collapses due to the influence of mixed noise such as ASE (Amplified Spontaneous Emission) from the optical amplifier OA, the influence of dispersion of the optical waveguide loop O-Loop, etc. It is known that it is difficult to maintain a data signal longer than the number of laps (see Non-Patent Document 1).

R. Langenhorst et al, “Fiber Loop Optical Buffer,” JOURNAL OF LIGHT WAVE TECHNOLOGY, IEEE, 1996, VOL. 14, NO.3, pp. 324-335 Ikuo Ogawa, 5 others, "PLC hybrid integrated semiconductor optical amplifier module", TECHNICAL REPORT OF IEICE., THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATION ENGINEERS, 2002, EMD2002-25, CPM2002-67, OPE2002-47, LQE2002- 102, pp. 7-11 Seiichi Itabashi, “Research and Development Trend of Silicon Photonics”, NTT Technical Journal, December 2009, pp. 12-15 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 provide an optical signal buffer memory circuit and an optical signal buffer method in an optical communication, an optical processing, and an optical computer with an optical delay of an arbitrary integer multiple of an optical signal length to be stored and output In addition, unlike the optical buffer memory described in [First Prior Art], “the optical circuit becomes larger as the pattern of the adjustable optical delay amount increases”. In addition, as in the optical buffer memory described in [Second Prior Art], “the influence of mixed noise such as ASE from the optical amplifier for loss compensation used in the optical buffer memory circuit or in the optical buffer memory circuit” In principle, there is an optical delay limit that can be applied due to degradation of the optical signal waveform due to the influence of the dispersion effect associated with optical waveguides, etc. It is to provide an optical signal buffer memory circuit to be able to.

That is, an object of the present invention is to provide an optical signal buffer memory circuit capable of providing an infinite optical delay amount with a simple configuration without causing waveform deterioration.
Furthermore, although details will be described later, the optical interference characteristics of the desired Mach-Zehnder interference type optical-optical phase modulation means are evaluated in a state where the oscillation behavior by the ring optical resonator unit is suppressed and this influence is eliminated. An object of the present invention is to provide an optical signal buffer memory circuit capable of performing balance adjustment.

The optical signal buffer memory circuit of the first invention for solving the above-mentioned problems is
An external optical input port P-OCLK-In for inputting the clock signal light CLK-1 output from the clock signal light source, and an optical output port located on the bar side with respect to the external optical input port P-OCLK-In Two optical interference arms having P-MZ-1-bar and an optical output port P-MZ-1-cross located on the cross side, and the optical interference arm located on the optical waveguide of one of the optical interference arms Optical phase modulation means L1-1 for modulating the phase of the optical signal train propagating through the inside, and the phase of the optical signal train propagating through the optical interference arm located on the optical waveguide of the other optical interference arm Mach-Zehnder interference type light intensity modulation means MZ-1 which has an optical phase modulation means R1-1 for applying modulation to the light and functions as a Mach-Zehnder type interferometer,
An optical waveguide 18 directly or indirectly connected to an external optical input port P-Data-In for inputting an optical signal sequence Data-1 having information to be stored, and guiding the optical signal sequence Data-1.
An optical input port P-C1-1 connected to the optical waveguide 18 to which an optical signal string Data-1 from the external optical input port P-Data-In is input, and the optical output port P-MZ-1-bar Or P-C1-2 to which an optical signal train from any one of the optical output ports P-MZ-1-cross is input, and optical output ports P-C1-3, P-C1-4, Optical branching unit C-1 for branching and outputting the optical signal 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 When,
An optical waveguide 14 that guides an optical signal 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;
The light from the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R for guiding the signal train;
Light from the optical output port P-C1-3 connected to the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L for guiding the signal train;
The optical signal 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 section DD-1 that generates an optical delay for adjusting the timing of reaching R1-1 to be greater than or equal to the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
As the clock signal light CLK-1, RZ (Return to Zero) type signal light is inputted from the external light input port P-OCLK-In,
When the optical signal string Data-1 synchronized with the clock of the clock signal light CLK-1 is input from the external optical input port P-Data-In, first, the input optical signal string Data-1 is changed. The phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock signal light An optical signal train CLK output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross by turning on or off each pulse of CLK-1. -1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1.
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using the DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock By turning each pulse of the signal light CLK-1 on or off, the rotation output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross The optical signal sequence CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1, and the data pattern The emissions be configured to maintain in the circuit,
As the optical phase modulators c1 and c2 in the optical circuit of the optical phase modulators R1-1 and L1-1, an optical semiconductor amplifier (SOA) that generates optical gain is used.
The optical signal string from the optical output port P-MZ-1-bar is guided on the optical waveguide 14 leading to the optical input port P-C1-2 or from the optical output port P-MZ-1-cross. A variable light intensity attenuating section VA-1 provided on the optical waveguide for guiding an optical signal train to the optical input port P-C1-2;
Alternatively, the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting an optical signal sequence for inducing an optical phase modulation action to the optical phase modulation means R1-1. To the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. It has variable light intensity attenuating sections VA-2 and VA-2 respectively provided on the optical waveguide 15L that are connected to guide the optical signal train from the optical output port P-C1-3. And

An optical signal buffer memory circuit according to a second invention is
In the optical signal buffer memory circuit according to the first invention,
Furthermore,
It is located on the optical waveguide of one of the optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and is located behind the optical phase modulation means L1-1 and propagates through the optical interference arm. Optical phase modulation means L1-2 for modulating the phase of the optical signal train;
It is located on the optical waveguide of the other optical interference arm of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and is located behind the optical phase modulation means R1-1 and propagates through the optical interference arm. Optical phase modulation means R1-2 for modulating the phase of the optical signal train;
An external optical input port P-FF-In for inputting an optical signal sequence FF-1 for flip-flop control of the data pattern maintained in the circuit;
An optical input port P-C3-2 and optical output ports P-C3-3, P-C3-4, and the optical signal train FF-1 input from the external optical input port P-FF-In An optical branching unit C-3 for inputting from the optical input port P-C3-2 and branching out to the optical output ports P-C3-3 and P-C3-4;
An optical waveguide 21 for guiding the optical signal string FF-1 from the external optical input port P-FF-In to the optical input port P-C3-2;
The light from the light output port P-C3-4 connected to the light input port P-R1-2 for inputting the light signal sequence for inducing the light phase modulation action to the light phase modulation means R1-2. An optical waveguide 22R for guiding the signal train;
Light from the optical output port P-C3-3 is connected to the optical input port P-L1-2 for inputting an optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-2. An optical waveguide 22L for guiding the signal train;
Optical signal trains provided on the optical waveguide 22L or the optical waveguide 22R and simultaneously output from the optical output ports P-C3-3 and P-C3-4 are the optical input ports P-L1-2 and P-. An optical waveguide section DD-2 that generates an optical delay for adjusting the timing to reach R1-2 to be greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
The optical signal string FF-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the data pattern is maintained in the circuit, when the optical signal sequence FF-1 is input from the external optical input port P-FF-In, the input optical signal sequence FF-1 is used to The phase modulation means R1-2 and L1-2 are driven to cause a phase difference in the optical signal sequence output from the phase modulation means R1-1 and L1-1, and each pulse of the optical signal sequence is turned on. Alternatively, the optical signal train CLK-1-out-DMZ1 output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross A flip-flop having a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1 is performed to circulate to the optical branching unit C-1.
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using the DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock By turning each pulse of the signal light CLK-1 on or off, the rotation output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross The optical signal sequence CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1, and the data pattern The chromatography down and maintains in the circuit.

An optical signal buffer memory circuit according to a third invention is
In the optical signal buffer memory circuit according to the second invention,
Furthermore,
An external optical input port P-ERS-In for inputting an optical signal string ERS-1 for erasing control for erasing the data pattern maintained in the circuit;
The optical input ports P-C2-1 and P-C2-2 and the optical output port P-C2-4 connected to the optical waveguide 18 are included, and the optical input ports P-C2-1 and P-C2-2 are included. An optical multiplexing unit C-2 for coupling the optical signal sequence input from the same optical output port P-C2-4 to the same,
An optical waveguide 16 for guiding an optical signal string from the external optical input port P-Data-In to the optical input port P-C2-1;
An optical waveguide 17 for guiding an optical signal string from the external optical input port P-ERS-In to the optical input port P-C2-2;
With
The optical signal string ERS-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the same data pattern as the data pattern of the optical signal sequence Data-1 or an inverted data pattern is maintained in the circuit, the optical signal sequence ERS-1 is input from the external optical input port P-ERS-In. The optical signal train ERS-1 and the optical signal train CLK- output from one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross. 1-out-DMZ1 is used to drive the phase modulation means R1-1 and L1-1 so that all the phases of the clock signal light CLK-1 propagating in the two optical interference arms are π. Modulate,
When the optical signal sequence FF-1 is input from the external optical input port P-FF-In simultaneously with the input of the optical signal sequence ERS-1, the input optical signal sequence FF-1 is used. The phase modulation means R1-2 and L1-2 are driven to further π-modulate the phase of the optical signal sequence output from the phase modulation means R1-1 and L1-1, and the optical signal sequence is By outputting from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross, the optical output port P-MZ-1-bar or the optical output port P- Any one of MZ-1-cross is returned to an initial state in which there is no light output.

An optical signal buffer memory circuit according to a fourth invention is
An external optical input port P-OCLK-In for inputting the clock signal light CLK-1 output from the clock signal light source, and an optical output port located on the bar side with respect to the external optical input port P-OCLK-In Two first optical interference arms having P-MZ-1-bar and an optical output port P-MZ-1-cross located on the cross side, on the optical waveguide of one of the first optical interference arms An optical phase modulation means L1-1 for modulating the phase of the optical signal train positioned and propagating in the optical interference arm, and the optical interference arm positioned on the optical waveguide of the other first optical interference arm Mach-Zehnder interference type optical intensity modulation means MZ-1 having optical phase modulation means R1-1 for modulating the phase of the optical signal train propagating therethrough and functioning as a Mach-Zehnder type interferometer ,
An optical waveguide 18 directly or indirectly connected to an external optical input port P-Data-In for inputting an optical signal sequence Data-1 having information to be stored, and guiding the optical signal sequence Data-1.
An optical input port P-C1-1 connected to the optical waveguide 18 to which an optical signal string Data-1 from the external optical input port P-Data-In is input, and the optical output port P-MZ-1-bar Or P-C1-2 to which an optical signal train from any one of the optical output ports P-MZ-1-cross is input, and optical output ports P-C1-3, P-C1-4, Optical branching unit C-1 for branching and outputting the optical signal 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 When,
An optical waveguide 14 that guides an optical signal 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;
The light from the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R for guiding the signal train;
Light from the optical output port P-C1-3 connected to the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L for guiding the signal train;
The optical signal 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 section DD-1 that generates an optical delay for adjusting the timing of reaching R1-1 to be greater than or equal to the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
As the clock signal light CLK-1, RZ (Return to Zero) type signal light is inputted from the external light input port P-OCLK-In,
When the optical signal string Data-1 synchronized with the clock of the clock signal light CLK-1 is input from the external optical input port P-Data-In, first, the input optical signal string Data-1 is changed. The phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms, and Light output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross by turning on or off each pulse of the clock signal light CLK-1 The signal train CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal train Data-1,
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms. By turning on or off each pulse of the clock signal light CLK-1, the light is output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross. The optical signal sequence CLK-1-out-DMZ1 of the circulation is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1, and the data In the optical signal the buffer memory circuit to maintain a pattern in said circuit,
Furthermore,
On the optical waveguide of one of the first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1, located on the rear stage side of the optical phase modulation means L1-1 and in the optical interference arm. Optical phase modulation means L1-2 for modulating the phase of the optical signal train propagating through
On the optical waveguide of the other first optical interference arm of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and located on the rear stage side of the optical phase modulation means R1-1, Optical phase modulation means R1-2 for modulating the phase of the optical signal train propagating through
An external optical input port P-FF-In for inputting an optical signal sequence FF-1 for flip-flop control of the data pattern maintained in the circuit;
An optical input port P-C3-2 and optical output ports P-C3-3, P-C3-4, and the optical signal train FF-1 input from the external optical input port P-FF-In An optical branching unit C-3 for inputting from the optical input port P-C3-2 and branching out to the optical output ports P-C3-3 and P-C3-4;
An optical waveguide 21 for guiding the optical signal string FF-1 from the external optical input port P-FF-In to the optical input port P-C3-2;
The light from the light output port P-C3-4 connected to the light input port P-R1-2 for inputting the light signal sequence for inducing the light phase modulation action to the light phase modulation means R1-2. An optical waveguide 22R for guiding the signal train;
Light from the optical output port P-C3-3 is connected to the optical input port P-L1-2 for inputting an optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-2. An optical waveguide 22L for guiding the signal train;
Optical signal trains provided on the optical waveguide 22L or the optical waveguide 22R and simultaneously output from the optical output ports P-C3-3 and P-C3-4 are the optical input ports P-L1-2 and P-. An optical waveguide section DD-2 that generates an optical delay for adjusting the timing to reach R1-2 to be greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
An optical input port P-MZ-2-In for inputting an optical signal string output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross; , Two optical output ports P-Data-Out located on the bar side with respect to the optical input port P-MZ-2-In and two optical output ports P-MON-Out located on the cross side An optical interference arm, an optical phase modulation means L-2 for modulating the phase of an optical signal train that is located on the optical waveguide of one of the second optical interference arms and propagates through the optical interference arm, and the other And an optical phase modulation means R-2 for modulating the phase of the optical signal train which is located on the optical waveguide of the second optical interference arm and propagates through the optical interference arm, and is a Mach-Zehnder type Functions as an interferometer And Tsu Ha-Zehnder interference type light intensity modulating means MZ-2,
An optical waveguide 30 that guides an optical signal 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-MZ-2-In When,
An external optical input port P-Gate-In for inputting an optical signal string Gate-1 for optical signal output opening / closing control for outputting an optical signal string of the data pattern maintained in the circuit; ,
An optical input port P-C4-2 and optical output ports P-C4-3 and P-C4-4, and the optical signal string Gate-1 input from the external optical input port P-Gate-In An optical branching unit C-4 for inputting from the optical input port P-C4-2 and branching out to the optical output ports P-C4-3 and P-C4-4;
An optical waveguide 41 for guiding the optical signal string Gate-1 from the external optical input / output port P-Gate-In to the optical input port P-C4-2;
An optical signal train from the optical output port P-C4-3 connected to an optical input port P-L2 for inputting a signal optical train for inducing an optical phase modulation action to the optical phase modulation means L-2. An optical waveguide 42L for guiding
An optical signal train from the optical output port P-C4-4 connected to an optical input port PR2-R2 for inputting a signal optical train for inducing an optical phase modulation action to the optical phase modulation means R-2. An optical waveguide 42R for guiding
An optical signal train provided on the optical waveguide 42L or the optical waveguide 42R and simultaneously output from the optical output ports P-C4-3 and P-C4-4 is sent to the optical input ports P-L2 and P-R2. And an optical waveguide section DD-3 that generates an optical delay for adjusting the arrival timing to be equal to or greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
The optical signal string FF-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the data pattern is maintained in the circuit, when the optical signal sequence FF-1 is input from the external optical input port P-FF-In, the input optical signal sequence FF-1 is used to The phase modulation means R1-2 and L1-2 are driven to cause a phase difference in the optical signal sequence output from the phase modulation means R1-1 and L1-1, and each pulse of the optical signal sequence is turned on. Alternatively, the optical signal train CLK-1-out-DMZ1 output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross A flip-flop having a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1 is performed to circulate to the optical branching unit C-1.
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms. By turning on or off each pulse of the clock signal light CLK-1, the light is output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross. The optical signal sequence CLK-1-out-DMZ1 of the circulation is circulated to the optical branching unit C-1 as a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1, and the data An optical signal sequence output from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross is stored in the circuit. After making a transition to a state that is repeatedly output as the same data pattern as the column Data-1,
The optical signal string Gate-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
When the optical signal sequence Gate-1 is input from the external optical input port P-Gate-In, the optical phase modulation means R-2 and L-2 are connected using the input optical signal sequence Gate-1. An optical signal that is driven and propagated through the two second optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-2, which is input from the optical input port P-MZ-2-In By generating a phase difference in the column, the optical signal sequence input from the optical input port P-MZ-2-In is converted into the optical output port P-Data only during the data length of the optical signal sequence Gate-1. -Output from Out,
As the optical phase modulators c1 and c2 in the optical circuit of the optical phase modulators R1-1 and L1-1, an optical semiconductor amplifier (SOA) that generates optical gain is used.
The optical signal string from the optical output port P-MZ-1-bar is guided on the optical waveguide 14 leading to the optical input port P-C1-2 or from the optical output port P-MZ-1-cross. A variable light intensity attenuating section VA-1 provided on the optical waveguide for guiding an optical signal train to the optical input port P-C1-2;
Alternatively, the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting an optical signal sequence for inducing an optical phase modulation action to the optical phase modulation means R1-1. To the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. It has variable light intensity attenuating sections VA-2 and VA-2 respectively provided on the optical waveguide 15L that are connected to guide the optical signal train from the optical output port P-C1-3. And

An optical signal buffer memory circuit according to a fifth invention is
In the optical signal buffer memory circuit according to the fourth invention,
Furthermore,
An external optical input port P-ERS-In for inputting an optical signal string ERS-1 for erasing control for erasing the data pattern maintained in the circuit;
The optical input ports P-C2-1 and P-C2-2 and the optical output port P-C2-4 connected to the optical waveguide 18 are provided. From the optical input ports P-C2-1 and P-C2-2, An optical multiplexer C-2 for coupling an input optical signal train to the same optical output port P-C2-4;
An optical waveguide 16 for guiding an optical signal string from the external optical input port P-Data-In to the optical input port P-C2-1;
An optical waveguide 17 for guiding an optical signal string from the external optical input port P-ERS-In to the optical input port P-C2-2;
With
The optical signal string ERS-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the same data pattern as the data pattern of the optical signal sequence Data-1 or an inverted data pattern is maintained in the circuit, the optical signal sequence ERS-1 is input from the external optical input port P-ERS-In. The optical signal train ERS-1 and the optical signal train CLK- output from one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross. The phase of the clock signal light CLK-1 propagating in the two first optical interference arms by driving the phase modulation means R1-1 and L1-1 using 1-out-DMZ1 Π-modulate all
When the optical signal sequence FF-1 is input from the external optical input port P-FF-In simultaneously with the input of the optical signal sequence ERS-1, the input optical signal sequence FF-1 is used. The phase modulation means R1-2 and L1-2 are driven to further π-modulate the phase of the optical signal sequence output from the phase modulation means R1-1 and L1-1, and the optical signal sequence is By outputting from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross, the optical output port P-MZ-1-bar or the optical output port P- Any one of MZ-1-cross is returned to an initial state in which there is no light output.

The optical signal buffer memory circuit of the sixth invention is
In the optical signal buffer memory circuit according to any one of the first to fifth inventions,
The variable light intensity attenuating unit VA-1 or the variable light intensity attenuating units VA-1 and VA-2 are constant voltage drive semiconductor EA modulators.

The optical signal buffer memory circuit of the seventh invention is
In the optical signal buffer memory circuit according to any one of the first to fifth inventions,
In the variable light intensity attenuating unit VA-1 or the variable light intensity attenuating units VA-1 and VA-2, the PL characteristic of the electroabsorption active layer is set to the short wavelength side by 100 nm or more with respect to the set operation wavelength. The semiconductor EA modulator is in a constant voltage driving state.

According to the present invention, it is possible to give an optical delay of an arbitrary integer multiple to the optical signal length to be stored for output, and there is a problem in the optical buffer memory described in [First Prior Art]. In the optical buffer memory described in [Second Prior Art], it is possible to overcome the problem that “the optical circuit becomes larger as the pattern of the adjustable optical delay amount increases”. Was caused by optical signal waveform deterioration due to the influence of mixed noise such as ASE from the optical amplifier for loss compensation used in the optical buffer memory circuit and the influence of the dispersion effect accompanying the optical waveguide in the optical buffer memory circuit. In other words, it is possible to provide an infinite optical delay amount in principle.
Further, the oscillation behavior by the ring type optical resonator unit is suppressed, and the optical interference characteristic of the desired Mach-Zehnder interference type optical-optical phase modulation means is evaluated in a state in which this influence is eliminated, and balance adjustment is performed. Can be made possible.

It is the schematic which shows the structural example of the optical signal buffer memory circuit by this invention. 1 is a schematic diagram illustrating a configuration example of an optical signal buffer memory circuit according to the present invention. It is the schematic which shows the structural example of the optical signal buffer memory circuit by this invention. It is the schematic which shows the structural example of the optical signal buffer memory circuit by this invention. 4 is a timing chart of various optical signal trains in the optical signal buffer memory circuit. (A)-(d) is the schematic which shows the structural example of the optical-optical phase modulation circuit used with an optical signal buffer memory circuit. It is the schematic which shows an example of the optical buffer circuit comprised from the optical delay waveguide array, optical switch, and optical coupler which were examined conventionally. It is the schematic which shows an example of the optical circulation type buffer circuit comprised from an optical waveguide loop, the optical amplifier for propagation compensation, and an optical switch.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The optical signal buffer memory circuit shown in FIGS. 1 and 2 has the same basic circuit configuration, but in FIG. 1, a variable light intensity attenuating unit VA-1 is provided on the input side of the optical coupling / branching unit C-1. FIG. 2 is different in that variable light intensity attenuation units VA-2 and VA-3 are provided on the output side of the optical coupling / branching unit C-1.
The optical signal buffer memory circuits shown in FIGS. 3 and 4 have the same basic circuit configuration, but in FIG. 3, a variable light intensity attenuating unit VA-1 is provided on the input side of the optical coupling / branching unit C-1. FIG. 4 is different in that variable light intensity attenuators VA-2 and VA-3 are provided on the output side of the optical coupling / branching unit C-1.

  1 to 6, the basic circuit configuration of the optical signal buffer memory circuit will be described first, and then the variable light intensity attenuators VA-1, VA-2, and VA-3 will be described.

(Description of basic circuit configuration of optical signal buffer memory circuit)
FIGS. 1 and 2 are different from FIGS. 3 and 4 only in whether or not an optical shutter function is added to the optical signal buffer memory circuit.
The optical signal buffer memory circuit is a planar optical circuit created as an integrated optical circuit on a compound semiconductor substrate, or created by hybrid integration of a quartz-based planar lightwave circuit (PLC) and a compound optical semiconductor device. It is a planar optical circuit (Non-Patent Document 2) or a planar optical circuit (Non-Patent Document 3) created as an integrated optical circuit on a silicon planar substrate. Details will be described below.

(Constitution)
In the optical signal buffer memory circuit of this embodiment shown in FIGS. 1 to 4, P-OCLK-In is a clock optical pulse output from the clock signal light source as shown by “OC source” in FIG. This is an external optical input port of the clock signal light CLK-1 that becomes an RZ (Return to Zero) type clock signal light having a constant peak light power.

  Further, P-Data-In is an optical signal sequence Data- that becomes an “optical signal sequence for data input for the purpose of storing in the optical signal buffer memory circuit” as indicated by “OD source” in FIG. 1 is an external optical input port.

  Further, P-FF-In indicates “a mark (1) of information of the optical signal train for data stored in the optical signal buffer memory circuit” as shown in “FF cntl.” Of FIG. This is an external optical input port of the optical signal sequence FF- 1 that becomes a so-called flip-flop control optical signal sequence that is input when performing a flip-flop operation that inverts all the spaces (0).

  Further, P-ERS-In is “an optical signal string for erasure control that is input when resetting the information stored in the optical signal buffer memory circuit” as indicated by “ERS cntl.” In FIG. Is an external optical input port of the optical signal train ERS-1.

  C-2 has optical input ports P-C2-1, P-C2-2, optical output ports P-C2-3, and P-C2-4. The external optical input port P-Data-In To the optical input port P-C2-1 through the optical waveguide 16 and the optical input port P-C2 from the external optical input port P-ERS-In through the optical waveguide 17 to the optical input port P-C2-1. -2 is output from the same optical output port P-C2-4, and one optical input port P-C1-1 of the subsequent 2 × 2 optical branching unit C-1 is output. This is a 2 × 1 optical multiplexing part for coupling to the optical waveguide 18 leading to

  In addition, if the optical signal sequences Data-1 and ERS-1 can be switched and input by an external device, for example, the external optical input port P-Data-In is optically transmitted without using the optical multiplexing unit C-2. The optical signal train Data-1 or the optical signal train ERS-1 may be directly input to the optical waveguide 18 from the external optical input port P-Data-In.

  MZ-1 is an optical circuit unit used as a Mach-Zehnder interference type optical intensity modulation means, and two first optical interference arms on the left and right sides (optical waveguides 11R, 12R, 13R and optical waveguides 11L, 12L, 13L). The optical waveguide 11R and the optical waveguide 11L are partially disposed close to each other to form a directional coupler, and the optical waveguide 13R and the optical waveguide 13L are also partially disposed close to each other. Thus, a directional coupler is configured.

  R1-1, R1-2, L1-1, and L1-2 are input from the external optical input port P-OCLK-In to the Mach-Zehnder interference type light intensity modulation means MZ-1, and are Mach-Zehnder interference type. Optical phase for modulating the phase of a clock optical signal sequence (first clock optical signal sequence and second clock optical signal sequence to be described later) propagating through the two left and right first optical interference arms of the optical intensity modulation means MZ-1. Modulation means. The optical phase modulation means R1-1, R1-2, L1-1, and L1-2 are arranged between two directional couplers. Specifically, the optical phase modulation means R1-1 is an optical waveguide 11R. Between the optical waveguide 12R, the optical phase modulation means R1-2 between the optical waveguide 12R and the optical waveguide 13R, and the optical phase modulation means L1-1 between the optical waveguide 11L and the optical waveguide 12L. The phase modulation means L1-2 is disposed between the optical waveguide 12L and the optical waveguide 13L. That is, the optical phase modulation means R1-2 is located on the rear stage side of the optical phase modulation means R1-1, and the optical phase modulation means L1-2 is located on the rear stage side of the optical phase modulation means L1-1.

  Here, the first clock optical signal sequence is an optical signal sequence obtained by branching the clock signal light CLK-1 with a directional coupler, and the second clock optical signal sequence is in phase with the first clock optical signal sequence. It is an optical signal train after being subjected to optical phase modulation by the modulation means R1-1 and L1-1.

  P-MZ-1-cross is an optical output port for outputting an optical signal string from the cross side with respect to the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1.

  Further, P-MZ-1-bar is the Mach-Zehnder interference light intensity modulation means MZ-1 from the bar side to the external optical input port P-OCLK-In of the Mach-Zehnder interference light intensity modulation means MZ-1. This is an optical output port that outputs an optical signal train CLK-1-out-DMZ1 that becomes the light intensity modulated light.

  C-1 has optical input ports P-C1-1, P-C1-2, optical output ports P-C1-3, P-C1-4, and the optical output of the optical multiplexing unit C-2. The optical signal train from the port P-C2-4 is input from the optical input port P-C1-1 and branched through the optical waveguide 18, and is split into the optical output ports P-C1-3 and P-C1-4. The optical signal train from the optical output port P-MZ-1-bar of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is output via the optical waveguide 14 to the optical input port P- This is an optical branching unit for inputting and branching from C1-2 to output from optical output ports P-C1-3 and P-C1-4.

  Further, P-R1-1 and P-L1-1 convert the optical signal sequence output from the optical output ports P-C1-3 and P-C1-4 of the optical branching unit C-1 to the optical waveguide 15R, An optical input port for inputting to the optical phase modulation means R1-1 and L1-1 in the two first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1 via 15L .

  C-3 has optical input ports P-C3-1, P-C3-2, optical output ports P-C3-3, and P-C3-4. The external optical input port P-FF-In From the optical output port P-C3-3 and P-C3-4, an optical branching unit for branching the input optical signal train via the optical waveguide 21 is provided.

  Further, P-R1-2 and P-L1-2 respectively convert the optical signal sequence output from the optical output ports P-C3-3 and P-C3-4 of the optical branching unit C-3 into the optical waveguide 22R, This is an optical input port for inputting to the optical phase modulation means R1-2 and L1-2 in the two first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1 via 22L. .

  Further, DD-1 is branched by the optical branching unit C-1, and optical phase modulation means R1 is added to two optical signal trains output from the optical output ports P-C1-3 and P-C1-4, respectively. -1 and L1-1 are optical propagation delay difference giving units for giving the optical propagation delay difference so as to be "more than the pulse width of the clock optical signal CLK-1 and less than the pulse repetition period" Here, the optical waveguide portion having the optical path length that causes the above-described optical propagation delay difference is arranged in the optical waveguide 15L.

  Further, DD-2 is optical phase modulation means R1- in the two optical signal trains branched from the optical branching section C-3 and output from the optical output ports P-C3-3 and P-C3-4. 2, an optical propagation delay difference providing unit for applying an optical propagation delay difference until reaching L1-2 to be “more than a pulse width of the clock optical signal CLK-1 and less than a pulse repetition period”; Here, an optical waveguide portion having an optical path length that causes the above-described optical propagation delay difference is arranged in the optical waveguide 22L.

  MZ-2 is an optical circuit unit used as Mach-Zehnder interference type light intensity modulation means, and has two right and left second optical interference arms (optical waveguides 31R and 32R and optical waveguides 31L and 32L). In the optical waveguide 31R and the optical waveguide 31L, a part is arranged close to each other to form a directional coupler, and in the optical waveguide 32R and the optical waveguide 32L, part is arranged close to each other, It constitutes a coupler.

  P-MZ-2-In transmits an optical signal string output from the optical output port P-MZ-1-cross of the Mach-Zehnder interference type optical intensity modulation means MZ-1 through the optical waveguide 30. These are optical input ports for inputting to the Mach-Zehnder interference type optical intensity modulation means MZ-2.

  P-Data-Out is an optical output port that outputs an optical signal train from the bar side to the optical input port P-MZ-2-In of the Mach-Zehnder interference type optical intensity modulation means MZ-2. P-MON-Out is an optical output port that outputs an optical signal train from the cross side.

  R-2 and L-2 are input from the optical input port P-MZ-2-In to the Mach-Zehnder interference type light intensity modulation means MZ-2, and are Mach-Zehnder interference type light intensity modulation means MZ-2. The optical phase modulation means modulates the phase of the optical signal train propagating through the two right and left second optical interference arms. The optical phase modulation means R-2 and L-2 are arranged between two directional couplers, and the optical phase modulation means R-2 is arranged between the optical waveguide 31R and the optical waveguide 32R. L-2 is disposed between the optical waveguide 31L and the optical waveguide 32L.

  Further, P-Gate-In is connected to the optical output port by performing a flip-flop operation after being stored in the optical signal buffer memory circuit, as shown in “Shutter cntl.” Of FIG. An optical signal sequence output from the P-MZ-1-cross, that is, an optical signal sequence having the same data pattern as that of the optical signal sequence Ddata-1 input for the purpose of storing in the optical signal buffer memory circuit is used as the optical signal sequence. This is an external optical input port of the optical signal sequence Gate-1 which becomes an optical signal sequence for optical shutter opening / closing control "that is input when the output port P-Data-Out is guided and output.

  C-4 has optical input ports P-C4-1, P-C4-2, optical output ports P-C4-3, and P-C4-4. The external optical input port P-Gate-In From the optical output port P-C4-3 and P-C4-4, an optical branching unit for branching the input optical signal train through the optical waveguide 41 is provided.

  Further, P-R2 and P-L2 are optical signal strings output from the optical output ports P-C4-3 and P-C4-4 of the optical branching unit C-4 via the optical waveguides 42R and 42L. These are optical input ports for inputting to the optical phase modulation means R-2 and L-2 in the two second optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-2.

  Further, DD-3 is branched by the optical branching section C-4, and optical phase modulation means R is respectively added to two optical signal trains output from the optical output ports P-C4-3 and P-C4-4. -2 and L-2 are optical propagation delay difference providing units for providing the optical propagation delay difference to be “more than the pulse width of the clock optical signal CLK-1 and less than the pulse repetition period”. Here, the optical waveguide portion having the optical path length causing the above-mentioned optical propagation delay difference is arranged in the optical waveguide 42R.

  The optical signal sequences FF-1, ERS-1, and Gate-1 that are optical signal sequences for control use, for example, one or individual generators that generate optical pulse sequences that are optical signal sequences. The external optical input ports P-FF-In, P-ERS-In, and P are synchronized with the clock signal light CLK-1 and the optical signal train Data-1 (or the optical signal train CLK-1-out-DMZ1). -Input only from Gate-In.

  Here, in the optical circuit of the present embodiment, the waveguide portion is constituted by a low-loss semiconductor waveguide, and the optical phase modulation means R1-1, R1-2, L1-1, L1-2, R-2, As L-2, a semiconductor optical amplifier (SOA) is used, or an optical semiconductor circuit comprising optical phase modulation means shown in FIGS. 6A to 6D described later is used, or a quantum dot SOA ( QD-SOA) is used, or a semiconductor EA (Electro-Absorption) modulator is used for constant voltage driving, and the entire structure is integrated with an optical semiconductor.

  Alternatively, in the optical circuit of the present embodiment, the optical waveguide portion is configured by PLC, and the optical phase modulation means R1-1, R1-2, L1-1, L1-2, R-2, L-2 are used as the SOA. Or a PLC-optical semiconductor hybrid circuit comprising optical phase modulation means shown in FIGS. 6A to 6D to be described later, QD-SOA, or semiconductor EA modulation. As a configuration using a constant voltage drive, the whole is manufactured by a hybrid of a quartz-based planar lightwave circuit (PLC) and an optical semiconductor (see Non-Patent Document 4).

  Alternatively, the optical circuit of this embodiment uses a photonic crystal waveguide for the optical waveguide portion, and optical phase modulation means R1-1, R1-2, L1-1, L1-2, R-2, L-2. The quantum dot group is embedded in the core layer, and the whole is integrated and manufactured (see Non-Patent Document 5).

Configuration examples of the optical phase modulation means R1-1, R1-2, L1-1, L1-2, R-2, L-2 used in the optical circuit of this embodiment are shown in FIGS. ) Will be described.
Here, for convenience, the two optical signal trains input to the optical-optical phase modulation means are referred to as “optical phase modulation signal light” and “optical phase modulation control signal light”.

The optical-optical phase modulation means shown in FIGS. 6A to 6D are produced by being integrated in the same planar substrate type optical circuit.
6 (a) to 6 (d), a1 and a2 are two optical input / output ports on one side of the entire optical circuit of the optical-optical phase modulation means, and a3 and a4 are the optical-optical phase modulation means. The two optical input / output ports on the other side of the entire optical circuit, b1 and b2 are multimode interference couplers (first and second optical interference type branching means), and a9 and a10 are one of the multimode interference couplers b1. Optical input / output ports, a5, a6 are the other optical input / output ports of the multimode interference coupler b1, a7, a8 are the one optical input / output ports of the multimode interference coupler b2, and a11, a12 are the other of the multimode interference coupler b1. , E1 and e2 are two optical input / output waveguides on one side of the entire optical circuit of the optical-optical phase modulation means, and e3 and e4 are the other optical circuit of the optical-optical phase modulation means. Two optical input / output waveguides on the side The optical waveguide e5 and e7 and e6 and e8 constituting the two left and right optical interference arms, c1, c2 are two optical phase modulation portion, d1, d2 are the optical phase adjusting section.
The multimode interference coupler b1 has two optical input / output ports a9, a10 on one side and two optical input / output ports a5, a6 on the other side, and the multimode interference coupler b2 has two optical input / output ports on one side. Ports a7 and a8 and two optical input / output ports a11 and a12 on the other side are provided.

The two optical input / output ports a1, a2 on one side of the entire optical circuit are connected to the optical input / output on one side of the multimode interference coupler b1 via the two optical input / output waveguides e1, e2 on one side of the entire optical waveguide. They are connected to ports a9 and a10, respectively.
The optical input / output ports a5 and a6 on the other side of the multimode interference coupler b1 are connected to one side of the optical phase modulators c1 and c2 via two optical waveguides e5 and e6 on one side, respectively.
The other sides of the optical phase modulators c1 and c2 are connected to the optical input / output ports a7 and a8 on one side of the multimode interference coupler b2 via the other two optical waveguides e7 and e8, respectively. That is, the optical phase modulators c1 and c2 are provided in each of two optical interference arms (optical waveguides e5 and e7 and optical waveguides e6 and e8).
The other optical input / output ports a11 and a12 of the multimode interference coupler b2 are connected to the other two optical input / output waveguides e3 and e4 on the other side of the entire optical circuit. These are connected to ports a1 and a2.

The optical phase adjusters d1 and d2 can adjust the phase of the signal light in accordance with the amount of injected current, and are provided in one or both of the two optical interference arms.
6B, the optical phase adjustment unit d1 is provided in the optical waveguide e7, the optical phase adjustment unit d2 is provided in the optical waveguide e8 in FIG. 6C, and the optical phase adjustment unit in FIG. 6D. d1 and d2 are provided in the optical waveguides e7 and e8, respectively. Although not limited to this, although not shown, the optical phase adjustment unit d1 is provided in the optical waveguide e5, the optical phase adjustment unit d2 is provided in the optical waveguide e6, or the optical phase adjustment units d1 and d2 are provided in the optical waveguide e5. , E6 may be provided respectively. Alternatively, the optical phase adjustment unit d1 is provided in the optical waveguide e7 and the optical phase adjustment unit d2 is provided in the optical waveguide e6, or the optical phase adjustment unit d1 is provided in the optical waveguide e5 and the optical phase adjustment unit d2 is provided in the optical waveguide e8. May be.

  In the multimode interference coupler b1, for example, “light phase modulated signal light” and “light phase modulation control signal light” are input from the two optical input / output ports a1 and a2 through the optical input / output ports a9 and a10, respectively. Then, the “light phase modulated signal light” and the “light phase modulation control signal light” input from the light input / output ports a1 and a2 are branched, respectively, and one of the branched “light phase modulated signal light” and “light One of the "phase modulation control signal light" is multiplexed and output from the optical input / output port a5, and the other of the branched "light phase modulated signal light" and the other of the "optical phase modulation control signal light" are multiplexed And output from the optical input / output port a6.

  Similarly, in the multi-mode interference coupler b2, for example, when two signal lights Sig-1 and Sig-2 output from the optical phase modulators c1 and c2 are individually input from the optical input / output ports a7 and a8, respectively, Sig-1 and signal light Sig-2 are respectively branched, one of the branched signal light Sig-1 and one of the signal light Sig-2 are combined and output from the optical input / output port a11, and the branched signal light The other of Sig-1 and the other of signal light Sig-2 are multiplexed and output from optical input / output port a12.

  The optical phase modulators c1 and c2 have an optical waveguide structure having a property that the refractive index changes in accordance with the optical intensity of the “optical phase modulation control signal light”, and are optical semiconductor amplifiers (SOA) having an optical waveguide structure. Either an optical waveguide structure including a quantum dot layer, or a semiconductor EA modulator in a constant voltage drive state. The optical phase modulator c1 is disposed between the optical waveguide e5 and the optical waveguide e7 (that is, one optical interference arm), and the optical phase modulator c2 is disposed between the optical waveguide e6 and the optical waveguide e8 (that is, the other optical interference). Arm).

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

  The optical path lengths of the two optical interference arms of the Mach-Zehnder interference circuit are strictly adjusted at the time of manufacture when no optical phase adjustment unit is provided as shown in FIG. When the optical phase adjustment units d1 and d2 are provided in one or both of the two optical interference arms as shown in FIG. 6 (d), the optical phase adjustment units d1 and d2 are used for precise adjustment during use.

With such a configuration, for example, “optical phase modulation control signal light” is input from the optical input / output port a1, and “optical phase modulation signal light” is input from the optical input / output port a2, and the optical phase modulation unit c1 C2, after applying optical phase modulation to the “light phase modulated signal light” by the “light phase modulation control signal light”, the “light phase modulated signal light” subjected to the optical phase modulation is applied only to the optical input / output port a4. The optical phase modulation control signal light can be selectively output only from the optical input / output port a3.
Or, conversely, “optical phase modulation control signal light” is input from either one of the optical input / output ports a3 and a4, and “optical phase modulation signal light” is input from either one of the optical input / output ports a3 and a4. After inputting and applying optical phase modulation to the “light phase modulated signal light” by the “optical phase modulation control signal light” in the optical phase modulators c 1 and c 2, only one of the optical input / output ports a 1 and a 2 From the optical input / output ports a1 and a2 and to selectively output the “optical phase modulation control signal light”. Is also possible.
Alternatively, “optical phase modulation control signal light” is input from either one of the optical input / output ports a1 and a2, and “optical phase modulation signal light” is input from either one of the optical input / output ports a3 and a4. After optical phase modulation is applied to the “light phase modulated signal light” by the “optical phase modulation control signal light” in the optical phase modulation units c1 and c2, the optical phase modulation units c1 and c2 are selectively selected from only one of the optical input / output ports a1 and a2. It is also possible to output “optical phase modulated signal light” that has undergone optical phase modulation, and to selectively output “optical phase modulation control signal light” from only one of the optical input / output ports a3 and a4. is there.
Or, conversely, "optical phase modulation control signal light" is input from either one of the optical input / output ports a3 and a4, and "optical phase modulation signal light" is input from either one of the optical input / output ports a1 and a2. After the optical phase modulation is applied to the “phase modulated signal light” by the “optical phase modulation control signal light” in the optical phase modulation units c1 and c2, only one of the optical input / output ports a3 and a4 is applied. From the optical input / output ports a1 and a2 and to selectively output the “optical phase modulation control signal light”. Is also possible.
That is, one of the optical input / output ports a1, a2, a3, a4 is set as an optical input port for inputting “optical phase modulation control signal light”, and any one optical input / output port is set. The port is set as an optical input port for inputting “light phase modulated signal light”, and any one of the optical input / output ports is set as an optical output port for outputting “light phase modulated signal light” subjected to optical phase modulation. By setting, one of the optical input / output ports can be set as an optical output port for outputting “optical phase modulation control signal light”.

  In the optical phase modulation means R1-1 in FIGS. 1 to 4, the “optical phase modulation control signal light” is the optical signal sequence Data-1 or the optical signal sequence CLK-1-out-DMZ1, and the optical input / output port a1. The “light-phase-modulated signal light” is the first clock optical signal train, and the light of the optical phase-modulating means R1-1 connected to the optical waveguide 11R. Light is input from the input port (corresponding to the optical input / output port a2), and light is transmitted from the optical output port (corresponding to the optical input / output port a4) of the optical phase modulation means R1-1 to which the optical waveguide 12R is connected. Only the first clock optical signal train subjected to the phase modulation (second first clock optical signal train) is selectively output. Although not shown in FIGS. 1 to 4, from the optical output port (corresponding to the optical input / output port a3) of the empty optical phase modulation means R1-1 to which nothing is coupled, "Modulation control signal light" (optical signal sequence Data-1 or optical signal sequence CLK-1-out-DMZ1) is output.

  In the optical phase modulation means L1-1 in FIGS. 1 to 4, the “optical phase modulation control signal light” is the optical signal sequence Data-1 or the optical signal sequence CLK-1-out-DMZ1, and the optical input / output port a1. The “light phase modulated signal light” is the first clock optical signal train, and the light of the optical phase modulation means L1-1 to which the optical waveguide 11L is connected is input from the optical input port P-L1-1 corresponding to Light is input from the input port (corresponding to the optical input / output port a2), and light is output from the optical output port (corresponding to the optical input / output port a4) of the optical phase modulation means L1-1 to which the optical waveguide 12L is connected. Only the first clock optical signal sequence (second clock optical signal sequence) that has undergone phase modulation is selectively output. Although not shown in FIGS. 1 to 4, from the optical output port (corresponding to the optical input / output port a3) of the empty optical phase modulation means L1-1 to which nothing is coupled, "Modulation control signal light" (optical signal sequence Data-1 or optical signal sequence CLK-1-out-DMZ1) is output.

  In the optical phase modulation means R1-2 in FIGS. 1 to 4, the “optical phase modulation control signal light” is an optical signal sequence FF-1 for flip-flop control, and an optical input port corresponding to the optical input / output port a1. The first clock optical signal sequence (second clock optical signal sequence) after being input from P-R1-2 and subjected to optical phase modulation by the optical phase modulation means R1-1. And is input from the input port (corresponding to the optical input / output port a4) of the optical phase modulation means R1-2 to which the optical waveguide 12R is connected, and the optical phase modulation means R1 to which the optical waveguide 13R is connected. -2 output port (corresponding to the optical input / output port a2), only the second clock optical signal train subjected to optical phase modulation is selectively output. Although not shown in FIGS. 1 to 4, from the optical output port (corresponding to the optical input / output port a3) of the vacant optical phase modulation means R1-2 to which nothing is coupled, Modulation control signal light "(optical signal string FF-1) is output.

  In the optical phase modulation means L1-2 in FIGS. 1 to 4, the “optical phase modulation control signal light” is an optical signal sequence FF-1 for flip-flop control, and an optical input port corresponding to the optical input / output port a1. The first clock optical signal sequence (second clock optical signal sequence) after being input from P-L1-2 and subjected to optical phase modulation by the optical phase modulation means L1-1. And is input from the input port (corresponding to the optical input / output port a4) of the optical phase modulation means L1-2 to which the optical waveguide 12L is connected, and the optical phase modulation means L1 to which the optical waveguide 13L is connected. -2 output port (corresponding to the optical input / output port a2), only the second clock optical signal train subjected to optical phase modulation is selectively output. Although not shown in FIGS. 1 to 4, from the optical output port (corresponding to the optical input / output port a3) of the vacant optical phase modulation means L1-2 to which nothing is coupled, Modulation control signal light "(optical signal string FF-1) is output.

  In the optical phase modulation means R-2 in FIGS. 3 and 4, the optical phase modulation control signal light is an optical signal sequence Gate-1 which becomes an optical signal sequence for optical shutter opening / closing control, and is connected to the optical input / output port a1. The “optical phase-modulated signal light” is input from the corresponding optical input port P-R2, and is output from the optical output port P-MZ-1-cross of the Mach-Zehnder interference type optical intensity modulation means MZ-1. An optical signal string input to the Zehnder interference type optical intensity modulation means MZ-2 and input from an input port (corresponding to the optical input / output port a2) of the optical phase modulation means R-2 to which the optical waveguide 31R is connected. Thus, the optical signal train (optical phase-modulated signal light) subjected to optical phase modulation from the output port (corresponding to the optical input / output port a4) of the optical phase modulation means R-2 to which the optical waveguide 32R is connected. ) Only selectively It becomes door. Although not shown in FIGS. 3 and 4, from the optical output port (corresponding to the optical input / output port a3) of the empty optical phase modulation means R-2 to which nothing is coupled, Modulation control signal light "(optical signal string Gate-1) is output.

  In the optical phase modulation means L-2 in FIGS. 3 and 4, the optical phase modulation control signal light is an optical signal sequence Gate-1 which becomes an optical signal sequence for optical shutter opening / closing control, and is connected to the optical input / output port a1. The “optical phase-modulated signal light” is input from the corresponding optical input port P-L2, and is output from the optical output port P-MZ-1-cross of the Mach-Zehnder interference type optical intensity modulation means MZ-1. This is an optical signal string input to the Zehnder interference type optical intensity modulation means MZ-2 and input from the input port (corresponding to the optical input / output port a2) of the optical phase modulation means L-2 to which the optical waveguide 31L is connected. Thus, the optical signal train (optical phase-modulated signal light) subjected to optical phase modulation from the output port (corresponding to the optical input / output port a4) of the optical phase modulation means L-2 to which the optical waveguide 32L is connected. ) Only selectively It becomes door. Although not shown in FIGS. 3 and 4, from the optical output port (corresponding to the optical input / output port a3) of the empty optical phase modulation means L-2 to which nothing is coupled, Modulation control signal light "(optical signal string Gate-1) is output.

  Next, operations in the optical signal buffer memory circuit of this embodiment, specifically, data holding (buffering), flip-flop, output, and stored data erasing will be described with reference to FIGS.

(Operation-Data retention)
In the standard Mach-Zehnder interferometric light intensity modulation means, the state where no phase difference occurs when light propagates through the two optical interference arms constituting the interferometer is the state where modulation driving is not performed. Yes, 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, an optical signal is output 100% from the bar side.

  Therefore, when the clock signal light CLK-1 is input from the external optical input port P-OCLK-In to the optical signal buffer memory circuit shown in FIG. 1, the clock optical signal CLK-1 is the 100% optical output port P-. State output from MZ-1-cross and no optical output is obtained from optical output port P-MZ-1-bar (empty state in which optical signal buffer memory circuit does not hold any information: initial state) It has become.

  At this time, as indicated by “OD source” in FIG. 5, the clock signal light CLK-1 continuously input from the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1 The optical signal sequence Data-1 that is synchronized with the input signal is input from the external optical input port P-Data-In, and drives the optical phase modulation means R1-1 and L1-1. The phase of the first clock optical signal train (clock signal light CLK-1) propagating through the optical interference arm is π-modulated to turn on or off each pulse of the first clock optical signal train.

  Then, π phase modulation is applied only to the clock pulse of the first clock optical signal sequence corresponding to the pulse at the position of Mark (1) of the optical signal sequence Data-1, and the space of the optical signal sequence Data-1 is added. Since the phase modulation is not applied to the clock pulse of the first clock optical signal sequence corresponding to the pulse at position (0), the optical output port of MZ-1 has the same data pattern as the optical signal sequence Data-1. It is output from P-MZ-1-bar. In FIG. 2, an 8-bit optical signal sequence “10101010” is input as an example of the optical signal sequence Data-1.

  The optical signal sequence CLK-1-out-DMZ1 output from P-MZ-1-bar, which has the same data pattern as the optical signal sequence Data-1, is transmitted via the optical branching unit C-1. In order to induce optical phase modulation by being input to the phase modulation means R1-1 and L1-1, the first optical interference on the left and right sides of the Mach-Zehnder interference type light intensity modulation means MZ-1 is also performed in the next round. The first clock optical signal sequence propagating in the arm is subjected to the same optical phase modulation as described above by the optical signal sequence CLK-1-out-DMZ1 having the same data pattern as the large optical signal sequence Data-1. As a result, it is repeatedly output from the optical output port P-MZ-1-bar of the MZ-1 with the same data pattern as that of the large optical signal sequence Data-1, and as a result, “Buffering Stat” of FIG. As shown in FIG. 2 (see the optical signal pulse train for three cycles of N = 1 to 3 in FIG. 2), the same data pattern as that of the optical signal sequence Data-1 is applied to the optical signal buffer memory circuit in a series of driving. It will be held as a state.

  At this time, as in the optical buffer memory described in [Second Prior Art], “the signal data pattern is held by continuing to propagate the large optical pulse train through the optical waveguide loop while repeating optical amplification. Unlike the case, in the present embodiment, the optical signal sequence Data-1 or the optical signal sequence CLK-1-out-DMZ1 that becomes the “optical phase modulation control signal light” is used to obtain “optical phase modulation signal light”. By turning on or off each pulse of the clock signal light CLK-1, the new optical signal string having the same data pattern as the optical signal string Data-1 is copied (copied). The effects of mixed noise such as ASE from the optical amplifier for loss compensation used in the optical system and the dispersion effect due to the optical waveguide in the optical buffer memory circuit can be eliminated. Noteworthy characteristic that it is no longer available for grant optical delay limits due occurs in is to be realized.

(Operation-flip-flop)
Further, in the state where the same data pattern as that of the optical signal sequence Data-1 is held in the optical signal buffer memory circuit as a series of driving states as described above, the “FF cntl.” In FIG. As described above, the clock signal light CLK-1 continuously inputted from the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is synchronized, and a series of driving states have already been achieved. The period of the optical signal sequence Data-1 and the same data pattern as that of the optical signal sequence Data-1 held as the data pattern is also synchronized. -In is input and drives the optical phase modulation means R1-2 and L1-2 to propagate in the left and right first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1. The phase of the second clock optical signal train (the first clock optical signal train subjected to phase modulation) is π-modulated to turn on or off each pulse of the second clock optical signal train.

  Then, due to the effect of a series of driving states that have already been held, the Mach-Zehnder interference type light intensity modulating means MZ is combined with the optical phase modulation given by π in the optical phase modulating means R1-1 and L1-1. The phase modulation of the first clock optical signal sequence propagating through the left and right first optical interference arms of −1 is the optical signal sequence Data-1 (or the optical signal sequence CLK-1-out-DMZ1). An optical signal sequence in which phase modulation of 2π is applied to the clock pulse of the first clock optical signal sequence corresponding to the pulse at the position of Mark (1) and phase modulation is not applied in the previous round. The clock pulse of the first clock optical signal sequence corresponding to the pulse at the position (0) of Data-1 (or optical signal sequence CLK-1-out-DMZ1) has a phase of π. So that the tone is given.

  As a result, the clock pulse train subjected to the optical phase modulation becomes a data pattern inverted from the optical signal train Data-1, and the optical output port P-MZ-1 of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is obtained. The clock pulse train output from -bar and simultaneously subjected to these optical phase modulations has the same data pattern as that of the optical signal sequence Data-1, and the optical output port of the Mach-Zehnder interference type optical intensity modulation means MZ-1 P-MZ-1-cross is output, and so-called flip-flop operation is realized. As a result, as shown in “Buffering State” in FIG. 5 (refer to the optical signal pulse train for two cycles of N = 4 to 5 in FIG. 2), the data pattern inverted from the optical signal sequence Data-1 (“ 01010101 "8-bit optical signal string) is held in the optical signal buffer memory circuit as a series of driving states.

(Operation-Output)
Further, as described above, the same data pattern as that of the optical signal sequence Data-1 is repeatedly output from the optical output port P-MZ-1-cross of the optical signal buffer memory circuit, and the optical input port P-MZ-2- In a state where the signal is input from In to the Mach-Zehnder interference type light intensity modulation means MZ-2, as shown in “Shutter cntl.” In FIG. 5, the outside of the Mach-Zehnder interference type light intensity modulation means MZ-1 The inverted data pattern of the optical signal sequence Data-1 (or the data signal-1 that is synchronized with the clock signal light CLK-1 continuously input from the optical input port P-OCLK-In and already held as a series of driving states (or The period of the optical signal sequence (the same data pattern as that of the optical signal sequence Data-1) that is repeatedly input to the optical input port P-MZ-2-In is also synchronized. Then, an optical signal sequence Gate-1 having the same length as the data length of this data pattern is input from the external optical input port P-Gate-In, and drives the optical phase modulation means R-2 and L-2. The phase of the optical signal sequence (the optical signal sequence having the same data pattern as that of the optical signal sequence Data-1) propagating through the left and right second optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-2 π modulated.

  Then, in the period when the optical phase modulation is performed, as shown in the output of FIG. 5 only during the time window in which the optical signal sequence Gate-1 is input, that is, during the data length of the optical signal sequence Gate-1. An optical signal sequence having the same data pattern as that of the optical signal sequence Data-1 input from the optical input port P-MZ-2-In of the Mach-Zehnder interference type optical intensity modulation means MZ-2 is used as the optical output port P-Data-. It can be output from Out.

(Operation-Reset)
Further, in the state where the same data pattern or inverted data pattern as that of the optical signal sequence Data-1 is held as a series of driving states in the optical signal buffer memory circuit as described above, “ERS cntl.” In FIG. As shown, the clock signal light CLK-1 continuously inputted from the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is synchronized, and a series of driving has already been performed. The period of the same data pattern or inverted data pattern as the optical signal sequence Data-1 held as the state is also synchronized, and the optical signal sequence ERS-1 having the same length as the data length of this data pattern is external light. Input from the input port P-ERS-In, already output from the optical output port P-MZ-1-bar, and optical phase modulation via the optical branching unit C-1 Along with the optical signal train CLK-1-out-DMZ1 input to the means R1-1 and L1-1, the optical phase modulation means R1-1 and L1-1 are driven, and the optical phase modulation means R1-1, In the SOA constituting L1-1, by utilizing the saturation effect on the control light pulse power of the phase modulation effect of the SOA due to the gain saturation effect, left and right of the Mach-Zehnder interference type light intensity modulation means MZ-1 All the phases of the first clock optical signal train propagating in the first optical interference arm are π-modulated.

  At the same time, as shown in “FF cntl.” In FIG. 5, the clock continues to be input from the external optical input port P-OCLK-In of the Mach-Zehnder interference type optical intensity modulation means MZ-1. The same data pattern or inverted data pattern as the optical signal string Data-1 that is synchronized with the signal light CLK-1 and is already held as a series of driving states (repeatedly input to the optical input port P-MZ-2-In The optical signal sequence FF-1 having the same length as the data length of the data pattern is also synchronized with the period of the optical signal sequence Data-1 and the same data pattern). Is input from −In, drives the optical phase modulation means R1-2 and L1-2, and propagates in the left and right first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1. A second optical clock signal train of the phase is π causing modulation.

  In general, the phase of the first clock optical signal sequence propagating in the left and right first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1 is modulated by 2π, and all clock pulses are optically output. By outputting from the port P-MZ-1-cross, no optical output can be obtained from the optical output port P-MZ-1-bar described above (the optical signal buffer memory circuit holds no information). No empty state: initial state).

  Here, although the optical waveguide 14 is connected to the optical output port P-MZ-1-bar and the optical signal train CLK-1-out-DMZ1 is circulated to the optical branching section C-1, the optical output is The optical waveguide 14 may be connected to the port P-MZ-1-cross so that the optical signal train CLK-1-out-DMZ1 circulates to the optical branching unit C-1. In that case, the optical propagation delay difference providing unit DD-1 is provided on the optical waveguide 15R, the optical propagation delay difference providing unit DD-2 is provided on the optical waveguide 22R, and the optical output port P-MZ. The optical waveguide 30 is connected to -1-bar.

  Similarly, here, an optical signal sequence having the same data pattern as the optical signal sequence Data-1 is output from the optical output port P-Data-Out, but the optical signal sequence is output from the optical output port P-MON-Out. An optical signal string having the same data pattern as that of Data-1 may be output. In that case, the optical propagation delay difference providing part DD-3 is provided on the optical waveguide 42L.

(Description of variable light intensity attenuator of optical signal buffer memory circuit)
When using the optical-optical phase modulation means in which the optical waveguide circuit configuration of the Mach-Zehnder interference type as described above is realized as an integrated optical circuit of a planar substrate type, a desired “signal light— Control light separation operation ”, that is,“ clock optical signal string input from one specific optical input / output port a2 of optical input / output ports a1 and a2 on one side of the optical-optical phase modulation means ” Optical phase modulation signal light ”is selectively output from one specific optical input / output port a4 of the optical input / output ports a3 and a4 on the other side of the optical-optical phase modulation means, “Optical phase modulation control signal light” such as the optical signal train CLK-1-out-DMZ1 previously subjected to optical intensity modulation, which is input from the specific other optical input port a1 of the optical input / output ports a1 and a2. The light input / output on the other side In order to selectively output from the specific other optical input / output port a3 of the ports a3 and a4, the balance of the effective length with respect to the signal light of the two optical waveguide arms (optical interference arms) constituting the interference system is required. It needs to be precisely adjusted.

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

In this balance adjustment, in the optical signal buffer memory circuit, an optical output port P-MZ-1-cross or an optical output port P-MZ-1-bar from which a clock signal light subjected to optical intensity modulation is output; An optical branching unit C-1 for branching the clock signal light subjected to optical intensity modulation output from the optical output port P-MZ-1-cross or P-MZ-1-bar, and optical-optical phase modulation means R1 -1 and L1-1 are connected by optical waveguides 15R and 15L to form a ring-shaped closed optical circuit.
Accordingly, when an optical semiconductor amplifier (SOA) that generates optical gain is used in the optical phase modulation means c1 and c2 inside the optical-optical phase modulation means R1-1 and L1-1, the ring-shaped closed circuit is used. The part becomes an optical resonator and is in an oscillation or a state in accordance with the oscillation, and the interference characteristics of this ring optical resonator are the optical interference of Mach-Zehnder interference type optical-optical phase modulation means R1-1 and L1-1. Affects properties.
For this reason, there has been a problem that it is very difficult to adjust the balance by evaluating the optical interference characteristics of the Mach-Zehnder interference type optical-optical phase modulation means R1-1 and L1-1.

  Therefore, in order to solve such a problem at the time of balance adjustment, the optical signal buffer memory circuit of this embodiment, as shown in FIGS. The variable light intensity attenuating units VA-1, VA-2, VA-3 that can give optical loss (light intensity attenuation) only to the initial balance adjustment to the optical signal train CLK-1-out-DMZ1 subjected to Is provided.

More specifically, in the optical signal buffer memory circuit shown in FIGS. 1 and 3, the optical output port P- of the Mach-Zehnder interference type optical intensity modulation means MZ-1 from which the optical signal train CLK-1-out-DMZ1 is output. On the optical waveguide 14 connecting the MZ-1-bar and the optical input port P-C1-2 of the optical branching unit C-1 that branches the optical signal train CLK-1-out-DMZ1, that is, the optical output port P-MZ A variable light intensity attenuating section VA-1 is provided on the optical waveguide 14 that guides the optical signal train CLK-1-out-DMZ1 from -1-bar to the optical input port P-C1-2.
When the optical signal train CLK-1-out-DMZ1 is output from the optical output port P-MZ-1-cross of the Mach-Zehnder interference type optical intensity modulator MZ-1 and input to the optical branching unit C-1. Includes an optical output port P-MZ-1-cross of the Mach-Zehnder interference type optical intensity modulation means MZ-1 from which the optical signal train CLK-1-out-DMZ1 is output, and an optical signal train CLK-1- The optical signal train CLK-1-out from the optical output port P-MZ-1-bar on the optical waveguide 14 connecting the optical input port P-C1-2 of the optical branching unit C-1 that branches out-DMZ1. A variable light intensity attenuator VA-1 may be provided on the optical waveguide 14 that guides the DMZ1 to the optical input port P-C1-2.

In the optical signal buffer memory circuit shown in FIGS. 2 and 4, the optical signal train CLK-1- output from the optical output port P-MZ-1-bar of the Mach-Zehnder interference type optical intensity modulation means MZ-1 The optical output ports P-C1-3 and P-C1-4 of the optical branching unit C-1 that branches out-DMZ1 and the optical signal train CLK-1-out-DMZ1 branched by the optical branching unit C-1 On the optical waveguides 15L and 15R connecting the optical input ports P-R1-1 and P-L1-1 of the input optical-optical phase modulation means R1-1 and L1-1, that is, for inducing the optical phase modulation action. An optical waveguide 15R connected to the optical input port P-R1-1 for inputting the optical signal sequence to the optical phase modulation means R1-1 and leading the optical signal sequence from the optical output port P-C1-4; The optical signal sequence for inducing the phase modulation action The variable light intensity attenuating section VA is connected to the optical waveguide 15L that is connected to the optical input port P-L1-1 for inputting to the means L1-1 and guides the optical signal train from the optical output port P-C1-3. -2 and VA-3.
When the optical signal train CLK-1-out-DMZ1 is output from the optical output port P-MZ-1-cross of the Mach-Zehnder interference type optical intensity modulator MZ-1 and input to the optical branching unit C-1. Similarly, an optical branching unit C- for branching the optical signal train CLK-1-out-DMZ1 output from the optical output port P-MZ-1-cross of the Mach-Zehnder interference type optical intensity modulation means MZ-1 Optical-optical phase modulation means R1-1 for inputting one optical output port P-C1-3, P-C1-4 and the optical signal train CLK-1-out-DMZ1 branched by the optical branching unit C-1 , L1-1 on the optical waveguides 15L and 15R connecting the optical input ports P-R1-1 and P-L1-1, that is, the optical signal train for inducing the optical phase modulation action is the optical phase modulation means R1-1. Optical input port PR for input -1 connected to the optical output port P-C1-4 to guide the optical signal string from the optical output port P-C1-4 and the optical signal string for inducing the optical phase modulation action are input to the optical phase modulator L1-1. The variable light intensity attenuators VA-2 and VA-3 are respectively connected to the optical waveguide 15L connected to the optical input port P-L1-1 for guiding the optical signal train from the optical output port P-C1-3. What is necessary is just to provide.

  As described above, since the variable light intensity attenuating units VA-1, VA-2, and VA-3 are provided in the optical signal buffer memory circuit, the variable light intensity attenuating units VA-1, VA-2, and VA− are provided during the initial balance adjustment. 3, the optical signal output from the optical output port P-MZ-1-bar or P-MZ-1-cross of the Mach-Zehnder interference type optical intensity modulation means MZ-1 and input to the optical branching unit C-1. For the column CLK-1-out-DMZ1 or the optical signal column CLK-1-out-DMZ1 branched by the optical branching unit C-1 and input to the optical-optical phase modulation means R1-1, L1-1 By giving sufficient optical loss (optical attenuation), the oscillation behavior by the ring optical resonator part in question is suppressed, and the desired Mach-Zehnder interference type optical-optical phase modulation means R1 in a state in which this influence is eliminated. -1, L1-1 optical interference It evaluates the sex, it is possible to adjust the balance.

  In addition, the variable light intensity attenuating portions VA-1, VA-2, and VA-3 are set to have a PL (photoluminescence) characteristic of the electroabsorption active layer that is set to the short wavelength side of 100 nm or more with respect to the set operation wavelength. By using the “voltage-driven semiconductor EA modulator”, excessive optical loss is not caused when the optical signal buffer memory circuit is used for the original purpose, and initial adjustment is performed only during initial adjustment. However, it is possible to give a sufficient optical loss to suppress the ring resonance that is an obstacle to this.

In the state where the balance adjustment is completed in the Mach-Zehnder interference type optical-optical phase modulation means R1-1 and L1-1 and is adjusted to a desired optical interference condition, the optical signal train CLK-1-out- Using DMZ1 as optical phase modulation control signal light, optical phase modulation is applied to the first clock optical signal sequence, and at the same time, the first clock optical signal sequence (second clock optical signal sequence) subjected to optical phase modulation is selectively used. It is possible to output.
For this reason, the ring type optical resonator in question is in a state in which a large optical loss of 20 dB or more is given to the included Mach-Zehnder interference type optical-optical phase modulation means R1-1 and L1-1. Even if the optical loss is not given by the variable light intensity attenuating parts VA-1, VA-2, and VA-3, the oscillation behavior by the ring optical resonator part in question can be suppressed.

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

MZ-1: Mach-Zehnder interference type light intensity modulation means

P-OCLK-In: External optical input port for clock signal light input P-MZ-1-bar: Optical output port P-MZ-1-cross located on the bar side with respect to P-OCLK-In: P-OCLK -Optical output port located on the cross side with respect to In

R1-1: Optical phase modulation means P-R1-1: Optical input port L1-1 for control light to the optical phase modulation means R1-1: Optical phase modulation means P-L1-1: Optical phase modulation means L1-1 Control light optical input port to

R1-2: Optical phase modulation means P-R1-2: Optical input port L1-2 for the control light to the optical phase modulation means R1-2: Optical phase modulation means P-L1-2: Optical phase modulation means L1-2 Control light optical input port to

C-1: Optical branching unit (optical branching means)
P-C1-1: Optical input port P-C1-2: Optical input port P-C1-3: Optical output port P-C1-4: Optical output port

C-2: Optical multiplexing unit (optical multiplexing means)
P-C2-1: Optical input port P-C2-2: Optical input port P-C2-3: Optical output port P-C2-4: Optical output port

C-3: Optical branching section (optical branching means)
P-C3-1: Optical input port P-C3-2: Optical input port P-C3-3: Optical output port P-C3-4: Optical output port

P-Data-In: External optical input port for data optical signal train input P-ERS-In: External optical input port for optical signal train input for storage information erasure control P-FF-In: Optical signal train for flip-flop control External optical input port for input

D-D-1: Light propagation delay difference giving unit (light propagation delay difference giving means)
DD-2: Light propagation delay difference providing unit (light propagation delay difference providing means)

MZ-2: Mach-Zehnder interference type light intensity modulation means

P-MZ-2-In: Optical input port P-Data-out: Optical output port for optical signal string output

R-2: Optical phase modulation means P-R2: Light input port for control light to optical phase modulation means R-2 L-2: Optical phase modulation means P-L2: Control light to optical phase modulation means L-2 Light input port

C-4: Optical branching unit (optical branching means)
P-C4-1: Optical input port P-C4-2: Optical input port P-C4-3: Optical output port P-C4-4: Optical output port

P-Gate-In: External optical input port for optical signal string input for optical signal output gate opening / closing control

DD-3: Light propagation delay difference giving unit (light propagation delay difference giving means)

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 × 2 optical switch

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

a1 to a12: optical input / output ports b1, b2: multimode interference coupler (first and second optical interference type coupling / branching means)
c1, c2: optical phase modulators d1, d2: optical phase adjusters e1-e4: optical input / output waveguides e5-e8: optical waveguide (optical interference arm)

Claims (7)

An external optical input port P-OCLK-In for inputting the clock signal light CLK-1 output from the clock signal light source, and an optical output port located on the bar side with respect to the external optical input port P-OCLK-In Two optical interference arms having P-MZ-1-bar and an optical output port P-MZ-1-cross located on the cross side, and the optical interference arm located on the optical waveguide of one of the optical interference arms Optical phase modulation means L1-1 for modulating the phase of the optical signal train propagating through the inside, and the phase of the optical signal train propagating through the optical interference arm located on the optical waveguide of the other optical interference arm Mach-Zehnder interference type light intensity modulation means MZ-1 which has an optical phase modulation means R1-1 for applying modulation to the light and functions as a Mach-Zehnder type interferometer,
An optical waveguide 18 directly or indirectly connected to an external optical input port P-Data-In for inputting an optical signal sequence Data-1 having information to be stored, and guiding the optical signal sequence Data-1.
An optical input port P-C1-1 connected to the optical waveguide 18 to which an optical signal string Data-1 from the external optical input port P-Data-In is input, and the optical output port P-MZ-1-bar Or P-C1-2 to which an optical signal train from any one of the optical output ports P-MZ-1-cross is input, and optical output ports P-C1-3, P-C1-4, Optical branching unit C-1 for branching and outputting the optical signal 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 When,
An optical waveguide 14 that guides an optical signal 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;
The light from the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R for guiding the signal train;
Light from the optical output port P-C1-3 connected to the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L for guiding the signal train;
The optical signal 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 section DD-1 that generates an optical delay for adjusting the timing of reaching R1-1 to be greater than or equal to the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
As the clock signal light CLK-1, RZ (Return to Zero) type signal light is inputted from the external light input port P-OCLK-In,
When the optical signal string Data-1 synchronized with the clock of the clock signal light CLK-1 is input from the external optical input port P-Data-In, first, the input optical signal string Data-1 is changed. The phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock signal light An optical signal train CLK output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross by turning on or off each pulse of CLK-1. -1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1.
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using the DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock By turning each pulse of the signal light CLK-1 on or off, the rotation output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross The optical signal sequence CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1, and the data pattern The emissions be configured to maintain in the circuit,
As the optical phase modulators c1 and c2 in the optical circuit of the optical phase modulators R1-1 and L1-1, an optical semiconductor amplifier (SOA) that generates optical gain is used.
The optical signal string from the optical output port P-MZ-1-bar is guided on the optical waveguide 14 leading to the optical input port P-C1-2 or from the optical output port P-MZ-1-cross. A variable light intensity attenuating section VA-1 provided on the optical waveguide for guiding an optical signal train to the optical input port P-C1-2;
Alternatively, the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting an optical signal sequence for inducing an optical phase modulation action to the optical phase modulation means R1-1. To the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. It has variable light intensity attenuating sections VA-2 and VA-2 respectively provided on the optical waveguide 15L that are connected to guide the optical signal train from the optical output port P-C1-3. An optical signal buffer memory circuit. The optical signal buffer memory circuit according to claim 1.
Furthermore,
It is located on the optical waveguide of one of the optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and is located behind the optical phase modulation means L1-1 and propagates through the optical interference arm. Optical phase modulation means L1-2 for modulating the phase of the optical signal train;
It is located on the optical waveguide of the other optical interference arm of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and is located behind the optical phase modulation means R1-1 and propagates through the optical interference arm. Optical phase modulation means R1-2 for modulating the phase of the optical signal train;
An external optical input port P-FF-In for inputting an optical signal sequence FF-1 for flip-flop control of the data pattern maintained in the circuit;
An optical input port P-C3-2 and optical output ports P-C3-3, P-C3-4, and the optical signal train FF-1 input from the external optical input port P-FF-In An optical branching unit C-3 for inputting from the optical input port P-C3-2 and branching out to the optical output ports P-C3-3 and P-C3-4;
An optical waveguide 21 for guiding the optical signal string FF-1 from the external optical input port P-FF-In to the optical input port P-C3-2;
The light from the light output port P-C3-4 connected to the light input port P-R1-2 for inputting the light signal sequence for inducing the light phase modulation action to the light phase modulation means R1-2. An optical waveguide 22R for guiding the signal train;
Light from the optical output port P-C3-3 is connected to the optical input port P-L1-2 for inputting an optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-2. An optical waveguide 22L for guiding the signal train;
Optical signal trains provided on the optical waveguide 22L or the optical waveguide 22R and simultaneously output from the optical output ports P-C3-3 and P-C3-4 are the optical input ports P-L1-2 and P-. An optical waveguide section DD-2 that generates an optical delay for adjusting the timing to reach R1-2 to be greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
The optical signal string FF-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the data pattern is maintained in the circuit, when the optical signal sequence FF-1 is input from the external optical input port P-FF-In, the input optical signal sequence FF-1 is used to The phase modulation means R1-2 and L1-2 are driven to cause a phase difference in the optical signal sequence output from the phase modulation means R1-1 and L1-1, and each pulse of the optical signal sequence is turned on. Alternatively, the optical signal train CLK-1-out-DMZ1 output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross A flip-flop having a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1 is performed to circulate to the optical branching unit C-1.
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using the DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two optical interference arms, and the clock By turning each pulse of the signal light CLK-1 on or off, the rotation output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross The optical signal sequence CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1, and the data pattern Optical signal buffer memory circuit, characterized in that to maintain the over on to the said circuit. The optical signal buffer memory circuit according to claim 2.
Furthermore,
An external optical input port P-ERS-In for inputting an optical signal string ERS-1 for erasing control for erasing the data pattern maintained in the circuit;
The optical input ports P-C2-1 and P-C2-2 and the optical output port P-C2-4 connected to the optical waveguide 18 are included, and the optical input ports P-C2-1 and P-C2-2 are included. An optical multiplexing unit C-2 for coupling the optical signal sequence input from the same optical output port P-C2-4 to the same,
An optical waveguide 16 for guiding an optical signal string from the external optical input port P-Data-In to the optical input port P-C2-1;
An optical waveguide 17 for guiding an optical signal string from the external optical input port P-ERS-In to the optical input port P-C2-2;
With
The optical signal string ERS-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the same data pattern as the data pattern of the optical signal sequence Data-1 or an inverted data pattern is maintained in the circuit, the optical signal sequence ERS-1 is input from the external optical input port P-ERS-In. The optical signal train ERS-1 and the optical signal train CLK- output from one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross. 1-out-DMZ1 is used to drive the phase modulation means R1-1 and L1-1 so that all the phases of the clock signal light CLK-1 propagating in the two optical interference arms are π. Modulate,
When the optical signal sequence FF-1 is input from the external optical input port P-FF-In simultaneously with the input of the optical signal sequence ERS-1, the input optical signal sequence FF-1 is used. The phase modulation means R1-2 and L1-2 are driven to further π-modulate the phase of the optical signal sequence output from the phase modulation means R1-1 and L1-1, and the optical signal sequence is By outputting from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross, the optical output port P-MZ-1-bar or the optical output port P- An optical signal buffer memory circuit, wherein any one of the MZ-1-cross is returned to an initial state where there is no optical output. An external optical input port P-OCLK-In for inputting the clock signal light CLK-1 output from the clock signal light source, and an optical output port located on the bar side with respect to the external optical input port P-OCLK-In Two first optical interference arms having P-MZ-1-bar and an optical output port P-MZ-1-cross located on the cross side, on the optical waveguide of one of the first optical interference arms An optical phase modulation means L1-1 for modulating the phase of the optical signal train positioned and propagating in the optical interference arm, and the optical interference arm positioned on the optical waveguide of the other first optical interference arm Mach-Zehnder interference type optical intensity modulation means MZ-1 having optical phase modulation means R1-1 for modulating the phase of the optical signal train propagating therethrough and functioning as a Mach-Zehnder type interferometer ,
An optical waveguide 18 directly or indirectly connected to an external optical input port P-Data-In for inputting an optical signal sequence Data-1 having information to be stored, and guiding the optical signal sequence Data-1.
An optical input port P-C1-1 connected to the optical waveguide 18 to which an optical signal string Data-1 from the external optical input port P-Data-In is input, and the optical output port P-MZ-1-bar Or P-C1-2 to which an optical signal train from any one of the optical output ports P-MZ-1-cross is input, and optical output ports P-C1-3, P-C1-4, Optical branching unit C-1 for branching and outputting the optical signal 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 When,
An optical waveguide 14 that guides an optical signal 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;
The light from the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means R1-1. An optical waveguide 15R for guiding the signal train;
Light from the optical output port P-C1-3 connected to the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. An optical waveguide 15L for guiding the signal train;
The optical signal 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 section DD-1 that generates an optical delay for adjusting the timing of reaching R1-1 to be greater than or equal to the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
As the clock signal light CLK-1, RZ (Return to Zero) type signal light is inputted from the external light input port P-OCLK-In,
When the optical signal string Data-1 synchronized with the clock of the clock signal light CLK-1 is input from the external optical input port P-Data-In, first, the input optical signal string Data-1 is changed. The phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms, and Light output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross by turning on or off each pulse of the clock signal light CLK-1 The signal train CLK-1-out-DMZ1 is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal train Data-1,
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms. By turning on or off each pulse of the clock signal light CLK-1, the light is output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross. The optical signal sequence CLK-1-out-DMZ1 of the circulation is circulated to the optical branching unit C-1 as the same data pattern as the data pattern of the optical signal sequence Data-1, and the data In the optical signal the buffer memory circuit to maintain a pattern in said circuit,
Furthermore,
On the optical waveguide of one of the first optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-1, located on the rear stage side of the optical phase modulation means L1-1 and in the optical interference arm. Optical phase modulation means L1-2 for modulating the phase of the optical signal train propagating through
On the optical waveguide of the other first optical interference arm of the Mach-Zehnder interference type optical intensity modulation means MZ-1, and located on the rear stage side of the optical phase modulation means R1-1, Optical phase modulation means R1-2 for modulating the phase of the optical signal train propagating through
An external optical input port P-FF-In for inputting an optical signal sequence FF-1 for flip-flop control of the data pattern maintained in the circuit;
An optical input port P-C3-2 and optical output ports P-C3-3, P-C3-4, and the optical signal train FF-1 input from the external optical input port P-FF-In An optical branching unit C-3 for inputting from the optical input port P-C3-2 and branching out to the optical output ports P-C3-3 and P-C3-4;
An optical waveguide 21 for guiding the optical signal string FF-1 from the external optical input port P-FF-In to the optical input port P-C3-2;
The light from the light output port P-C3-4 connected to the light input port P-R1-2 for inputting the light signal sequence for inducing the light phase modulation action to the light phase modulation means R1-2. An optical waveguide 22R for guiding the signal train;
Light from the optical output port P-C3-3 is connected to the optical input port P-L1-2 for inputting an optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-2. An optical waveguide 22L for guiding the signal train;
Optical signal trains provided on the optical waveguide 22L or the optical waveguide 22R and simultaneously output from the optical output ports P-C3-3 and P-C3-4 are the optical input ports P-L1-2 and P-. An optical waveguide section DD-2 that generates an optical delay for adjusting the timing to reach R1-2 to be greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
An optical input port P-MZ-2-In for inputting an optical signal string output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross; , Two optical output ports P-Data-Out located on the bar side with respect to the optical input port P-MZ-2-In and two optical output ports P-MON-Out located on the cross side An optical interference arm, an optical phase modulation means L-2 for modulating the phase of an optical signal train that is located on the optical waveguide of one of the second optical interference arms and propagates through the optical interference arm, and the other And an optical phase modulation means R-2 for modulating the phase of the optical signal train which is located on the optical waveguide of the second optical interference arm and propagates through the optical interference arm, and is a Mach-Zehnder type Functions as an interferometer And Tsu Ha-Zehnder interference type light intensity modulating means MZ-2,
An optical waveguide 30 that guides an optical signal 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-MZ-2-In When,
An external optical input port P-Gate-In for inputting an optical signal string Gate-1 for optical signal output opening / closing control for outputting an optical signal string of the data pattern maintained in the circuit; ,
An optical input port P-C4-2 and optical output ports P-C4-3 and P-C4-4, and the optical signal string Gate-1 input from the external optical input port P-Gate-In An optical branching unit C-4 for inputting from the optical input port P-C4-2 and branching out to the optical output ports P-C4-3 and P-C4-4;
An optical waveguide 41 for guiding the optical signal string Gate-1 from the external optical input / output port P-Gate-In to the optical input port P-C4-2;
An optical signal train from the optical output port P-C4-3 connected to an optical input port P-L2 for inputting a signal optical train for inducing an optical phase modulation action to the optical phase modulation means L-2. An optical waveguide 42L for guiding
An optical signal train from the optical output port P-C4-4 connected to an optical input port PR2-R2 for inputting a signal optical train for inducing an optical phase modulation action to the optical phase modulation means R-2. An optical waveguide 42R for guiding
An optical signal train provided on the optical waveguide 42L or the optical waveguide 42R and simultaneously output from the optical output ports P-C4-3 and P-C4-4 is sent to the optical input ports P-L2 and P-R2. And an optical waveguide section DD-3 that generates an optical delay for adjusting the arrival timing to be equal to or greater than the pulse width of the clock signal light CLK-1 and less than the pulse repetition period;
With
The optical signal string FF-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the data pattern is maintained in the circuit, when the optical signal sequence FF-1 is input from the external optical input port P-FF-In, the input optical signal sequence FF-1 is used to The phase modulation means R1-2 and L1-2 are driven to cause a phase difference in the optical signal sequence output from the phase modulation means R1-1 and L1-1, and each pulse of the optical signal sequence is turned on. Alternatively, the optical signal train CLK-1-out-DMZ1 output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross A flip-flop having a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1 is performed to circulate to the optical branching unit C-1.
Subsequent rounds are the previous rounds of the optical signal train CLK-1-out- output from either the optical output port P-MZ-1-bar or the optical output port P-MZ-1-cross. Using DMZ1, the phase modulation means R1-1 and L1-1 are driven to cause a phase difference in the clock signal light CLK-1 propagating through the two first optical interference arms. By turning on or off each pulse of the clock signal light CLK-1, the light is output from either the light output port P-MZ-1-bar or the light output port P-MZ-1-cross. The optical signal sequence CLK-1-out-DMZ1 of the circulation is circulated to the optical branching unit C-1 as a data pattern obtained by inverting the data pattern of the optical signal sequence Data-1, and the data An optical signal sequence output from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross is stored in the circuit. After making a transition to a state that is repeatedly output as the same data pattern as the column Data-1,
The optical signal string Gate-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
When the optical signal sequence Gate-1 is input from the external optical input port P-Gate-In, the optical phase modulation means R-2 and L-2 are connected using the input optical signal sequence Gate-1. An optical signal that is driven and propagated through the two second optical interference arms of the Mach-Zehnder interference type optical intensity modulation means MZ-2, which is input from the optical input port P-MZ-2-In By generating a phase difference in the column, the optical signal sequence input from the optical input port P-MZ-2-In is converted into the optical output port P-Data only during the data length of the optical signal sequence Gate-1. -Output from Out,
As the optical phase modulators c1 and c2 in the optical circuit of the optical phase modulators R1-1 and L1-1, an optical semiconductor amplifier (SOA) that generates optical gain is used.
The optical signal string from the optical output port P-MZ-1-bar is guided on the optical waveguide 14 leading to the optical input port P-C1-2 or from the optical output port P-MZ-1-cross. A variable light intensity attenuating section VA-1 provided on the optical waveguide for guiding an optical signal train to the optical input port P-C1-2;
Alternatively, the optical output port P-C1-4 connected to the optical input port P-R1-1 for inputting an optical signal sequence for inducing an optical phase modulation action to the optical phase modulation means R1-1. To the optical input port P-L1-1 for inputting the optical signal sequence for inducing the optical phase modulation action to the optical phase modulation means L1-1. It has variable light intensity attenuating sections VA-2 and VA-2 respectively provided on the optical waveguide 15L that are connected to guide the optical signal train from the optical output port P-C1-3. An optical signal buffer memory circuit. The optical signal buffer memory circuit according to claim 4.
Furthermore,
An external optical input port P-ERS-In for inputting an optical signal string ERS-1 for erasing control for erasing the data pattern maintained in the circuit;
The optical input ports P-C2-1 and P-C2-2 and the optical output port P-C2-4 connected to the optical waveguide 18 are provided. From the optical input ports P-C2-1 and P-C2-2, An optical multiplexer C-2 for coupling an input optical signal train to the same optical output port P-C2-4;
An optical waveguide 16 for guiding an optical signal string from the external optical input port P-Data-In to the optical input port P-C2-1;
An optical waveguide 17 for guiding an optical signal string from the external optical input port P-ERS-In to the optical input port P-C2-2;
With
The optical signal string ERS-1 is synchronized with the clock of the clock signal light CLK-1, is synchronized with the cycle of the data pattern, and has the same length as the data length of the data pattern. Signal sequence,
After the same data pattern as the data pattern of the optical signal sequence Data-1 or an inverted data pattern is maintained in the circuit, the optical signal sequence ERS-1 is input from the external optical input port P-ERS-In. The optical signal train ERS-1 and the optical signal train CLK- output from one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross. The phase of the clock signal light CLK-1 propagating in the two first optical interference arms by driving the phase modulation means R1-1 and L1-1 using 1-out-DMZ1 Π-modulate all
When the optical signal sequence FF-1 is input from the external optical input port P-FF-In simultaneously with the input of the optical signal sequence ERS-1, the input optical signal sequence FF-1 is used. The phase modulation means R1-2 and L1-2 are driven to further π-modulate the phase of the optical signal sequence output from the phase modulation means R1-1 and L1-1, and the optical signal sequence is By outputting from either one of the optical output port P-MZ-1-bar and the optical output port P-MZ-1-cross, the optical output port P-MZ-1-bar or the optical output port P- An optical signal buffer memory circuit, wherein any one of the MZ-1-cross is returned to an initial state where there is no optical output. The optical signal buffer memory circuit according to any one of claims 1 to 5,
The variable light intensity attenuating unit VA-1 or the variable light intensity attenuating units VA-1 and VA-2 is a semiconductor EA modulator in a constant voltage driving state. The optical signal buffer memory circuit according to any one of claims 1 to 5,
In the variable light intensity attenuating unit VA-1 or the variable light intensity attenuating units VA-1 and VA-2, the PL characteristic of the electroabsorption active layer is set to the short wavelength side by 100 nm or more with respect to the set operation wavelength. An optical signal buffer memory circuit, which is a semiconductor EA modulator in a constant voltage driving state.

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