JP2766314B2 - Two-dimensional optical concentrator switch - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concentrator switch in a communication network, and more particularly to a two-dimensional optical concentrator switch for switching an optical signal as it is.

(Prior art) In order to realize high-speed and broadband services such as moving image information and large-capacity data communication, not only optical transmission lines are used, but optical communication information is exchanged as light as an exchange. It is effective to use an optical switch that performs the switching.

In an optical switching system that accommodates a large number of input optical fiber lines, an optical concentrator switch is provided in front of the optical distribution switch in order to increase the efficiency of the optical distribution switch for making arbitrary connections between the incoming and outgoing lines and to increase the economic efficiency. Provided.

Optical concentrator switches accommodate a large number of incoming lines with low usage rates,
It has the function of connecting only the line from which a call has been made to the outgoing line (the number of outgoing lines is usually smaller than the number of incoming lines). Thereby, the use efficiency of the optical distribution switch can be improved.

FIG. 2 is a configuration diagram showing a conventional optical line switch using a plurality of small-scale waveguide type optical switches, for example, a plurality of 4 × 4 optical matrix switches having four input lines and four output lines.

In FIG. 2, 1 is an incoming line, 2 is a group of 4 × 4 optical matrix switches in which eight 4 × 4 optical matrix switches are juxtaposed, and 3 is a first 2 in which 16 2 × 1 optical couplers are juxtaposed. × 1
The optical coupler group 4 is a second optical coupler group including eight 2 × 1 optical couplers.
2 × 1 optical coupler group and 5 are outgoing lines.

In FIG. 2, a 4 × 4 optical matrix switch group 2, a first 2 × 1 optical coupler group 3, a second 2 ×
The optical matrix switches of the 4 × 4 optical matrix switch group 2 and the first 2 ×
By connecting each optical coupler of the first optical coupler group 3 to each optical coupler of the first optical coupler group 3 and each optical coupler of the second optical coupler group 4, the number of input lines is 32 and the number of output lines is 32. This constitutes a large-scale optical concentrator switch having eight lines.

(Problems to be Solved by the Invention) However, in the above conventional configuration, the number of optical switches and optical couplers to be used is large, and furthermore, between these optical switches and optical couplers or between optical couplers arranged in multiple stages. There has been a problem that the amount of wiring to be connected is enormous, and the size of the entire optical concentrator switch is increased.

This problem will be described more specifically with reference to FIG.

FIG. 3 is a configuration diagram showing a conventionally proposed optical concentrator switch having 1024 incoming lines and 64 outgoing lines (P. Granestrand, Literature).
B. Stoltz, L. Thylen, K. Bergvall, W. Doldissen, H. Heidric
h, and D.Hoffmann, “Strictly nonblocking8 × 8integra
ted optical switch matrix ", Electronics Letters vo
l.22, pp. 816-818, 1986).

In FIG. 3, reference numeral 6 denotes an 8 × 8 optical matrix switch array having 128 structural parameters of 1 mm × 6 mm × 60 mm.
Pieces of lithium niobate waveguide type 8 × 8 optical switch SW
They are arranged in a matrix of 32 rows and 4 columns.

7 is the first 2 × 1 optical coupler array, 3 mm × 3 mm × 40 mm
512 2 × 1 optical couplers CP having the following structural parameters:
They are arranged in a matrix of 2 rows and 16 columns.

Reference numeral 8 denotes a second 2 × 1 optical coupler array, which includes 256 2 × 1 optical couplers CP having the same structural parameters as described above in 16 rows and 1 row.
They are arranged in a matrix of six columns.

Reference numeral 9 denotes a third 2 × 1 optical coupler array in which 128 2 × 1 optical couplers CP having the same structural parameters as described above are provided in 8 rows and 1 row.
They are arranged in a matrix of six columns.

The optical concentrator switch shown in FIG. 3 is 8 × 8 from the input side.
Optical matrix switch array 6, first 2 × 1 optical coupler array 7, second 2 × 1 optical coupler array 8, third 2 ×
One optical coupler array 9 is arranged in this order, and each optical switch SW is connected to each optical coupler CP, and each optical coupler CP is connected to each other to form an optical line switch.

In this configuration, the entire 8 × 8 optical matrix switch SW
Are used as many as 128, and 2x1 optical coupler CP as 896.
When the wiring length between the optical switch and the optical coupler is included, as shown in Fig. 3, 96mm x 48mm x 480m including the wiring length of 100mm / step
m (about 2200cm ³ ). In addition, in the configuration example of FIG. 3, the optical matrix switches SW and the 2 × 1 optical couplers CP are simply stacked, but when manufacturing, various restrictions are added, so that a certain amount of space is required. Yes, it is considered that in practice it will be larger than the above structural parameters.

The present invention has been made in view of such circumstances,
An object of the present invention is to provide a two-dimensional optical concentrator switch having a small size and a high mounting density.

(Means for Solving the Problems) In order to achieve the above object, in claim (1), in a two-dimensional optical line switch accommodating an optical fiber line, each optical signal transmitted through the optical fiber line enters. An input optical fiber array in which a plurality of optical fibers are two-dimensionally arranged, and an output light for each optical fiber of the input optical fiber array is made to go straight for each output light or to a predetermined direction in a direction perpendicular to the propagation direction. A polarization control element that controls a polarization direction of incident light according to a supply state of an electric signal, and a plurality of cells that individually shift with a distance;
A birefringent plate disposed on a light incident side or a light emitting side of the polarization control element; and a light receiving / processing circuit for controlling a supply state of an electric signal to the polarization control element according to a light receiving state of the incident light beam. And at least one optical beam shifter, and an output optical fiber array in which a plurality of optical fibers, each of which emitted light of the optical beam shifter is incident on one end surface thereof, are two-dimensionally arranged.

According to a second aspect of the present invention, in the two-dimensional optical concentrator switch accommodating an optical fiber line, an input optical fiber in which a plurality of optical fibers to which respective optical signals transmitted through the optical fiber line are respectively incident is two-dimensionally arranged. An array, and a plurality of cells that make the outgoing light for each optical fiber of the input optical fiber array go straight for each outgoing light or individually shift at a predetermined distance in a direction perpendicular to the propagation direction thereof. Is a polarization control element that controls the polarization direction of the incident light according to the supply state of the electric signal, a birefringent plate disposed on the light incident side or the light output side of the polarization control element, At least one light beam shifter comprising: a light receiving / processing circuit for controlling a supply state of an electric signal to the polarization control element according to a use state of the cell; and the light beam shifter. Each emitted light is configured to include an output optical fiber array a plurality of optical fibers are arranged two-dimensionally incident respectively on one end face.

In claim (3), claim (1) or (2)
In the two-dimensional optical concentrator switch described above, the output light for each optical fiber of the input optical fiber array is converted into a parallel light beam, and the input lens array for inputting these light beams to the light beam shifter is connected to the input optical fiber array. An output lens array disposed between the light emitting side of the light beam shifter and the light incident side of the light beam shifter and coupling each of the output light beams of the light beam shifter to one end face of each optical fiber of the output optical fiber array. The structure was arranged between the light emitting side of the beam shifter and the light incident side of the output optical fiber array.

According to claim (4), in the two-dimensional optical concentrator switch according to any one of claims (1) to (3), the first light beam shifter has the same shift direction for all the incident light beams. And a second light beam shifter in a shift direction in which the first light beam shifter is rotated by 90 degrees about the light beam propagation direction. The first and second light beam shifters are alternately arranged one or more stages each. Alternatively, it is configured to be arranged in multiple stages by an arbitrary combination.

According to claim (5), in the two-dimensional optical concentrator switch according to any one of claims (1) to (3), the shift directions are opposite to each other so as to collect light beams from both sides toward the center line. A first light beam shifter and the first light beam shifter;
And a second light beam shifter in a shift direction in which the light beam shifter is rotated by 90 degrees about the light beam propagation direction, and the first and second light beam shifters are alternately arranged one or more stages at a time or in any combination. It was configured to be arranged in multiple stages.

According to claim (6), in the two-dimensional optical concentrator switch according to any one of claims (1) to (3), the light beam is spirally collected from the outer peripheral portion so as to collect the light beam toward the center point. A configuration including a shifting light beam shifter was adopted.

According to claim (7), in the two-dimensional optical concentrator switch according to any one of claims (1) to (3), the light beam is linearly collected from the outer peripheral portion toward the center so as to collect the light beam toward the center point. And a light beam shifter for shifting the light beam.

Further, in claim (8), in the two-dimensional optical concentrator switch according to any one of claims (1) to (7), a configuration is provided in which a light beam shifter having a shift distance of one cell or a plurality of cells is provided.

According to a ninth aspect of the present invention, in the two-dimensional optical concentrator switch according to the eighth aspect, an optical beam shifter that is a power cell of which the shift distance is 2 is provided.

According to a tenth aspect, in the two-dimensional optical concentrator switch according to any one of the first to ninth aspects, a lens array for suppressing the spread of the light beam is arranged between the stages of the light beam shifter. The configuration was as follows.

Also, in claim (11), in the two-dimensional optical concentrator switch according to any one of claims (1) to (10), incident light is converted into two orthogonal polarization components on the light incident side of the first stage light beam shifter. Separating, allowing one of the separated components to go straight,
Means for shifting the other by a predetermined number of cells, and a polarization separating means comprising means for rotating one polarization direction of the emitted light of the means by 90 degrees and aligning the polarization directions of both,
And, on the light emission side of the last stage light beam shifter, one of the polarization directions of the light emitted from one shift cell of the light beam shifter and the light emitted from cells separated by a predetermined number of cells is changed.
A configuration is provided in which a polarization synthesizing means including a means for rotating 90 degrees and a means for shifting one of the light emitted from the means by a predetermined number of cells and synthesizing the two emitted lights is arranged.

(Operation) According to claim (1), the optical signal incident on each optical fiber of the input optical fiber array propagates through these optical fibers, then exits from the end faces thereof, and enters the respective cells of the optical beam shifter. I do.

The light signal that has entered the cell is received by the light receiving / processing circuit, thereby generating a light receiving signal indicating that the light signal (light beam) has been detected. The state of supply of the electric signal to the polarization control element, that is, supply or non-supply, is controlled in accordance with the generation or non-generation of the received light signal, whereby the polarization of the incident light is rotated or the polarization plane is rotated without rotation. In order to maintain the incident light, the incident light is shifted by a predetermined distance in the direction perpendicular to the propagation direction by the action of the birefringent plate and is emitted from the light beam shifter, or the light is left without being affected by the shift action. The light goes straight and exits the light beam shifter.

Each optical signal that is shifted in this way or travels straight without undergoing a shift action exits the optical beam shifter, enters each end face of each optical fiber of the output optical fiber array, and propagates through these optical fibers. Thereafter, the light is output from the other end face as output light of the optical concentrator switch.

Further, according to claim (2), the optical signal incident on each optical fiber of the input optical fiber array, after propagating through these optical fibers, exits from the end faces thereof and enters each cell of the optical beam shifter.

The light signal that has entered the cell is received by the light receiving / processing circuit, thereby generating a light receiving signal indicating that the light signal (light beam) has been detected. The supply state of the electric signal to the polarization control element, that is, supply or non-supply, is suppressed in accordance with the generation or non-generation of this light receiving signal and the use condition of another cell (the incident state of the optical signal). In order to rotate the polarized light or to maintain its plane of polarization without rotating it, the incident light is subjected to a shift action that is shifted by a predetermined distance in a direction perpendicular to its propagation direction by the action of a birefringent plate, and the light is shifted. The light beam is shifted out of the beam shifter, or the light beam shifter is straightly advanced without being subjected to the shift action.

Each optical signal that is shifted in this way or travels straight without undergoing a shift action exits the optical beam shifter, enters each end face of each optical fiber of the output optical fiber array, and propagates through these optical fibers. Thereafter, the light is output from the other end face as output light of the optical concentrator switch.

Further, according to claim (3), the optical signals respectively emitted from the end faces of the respective optical fibers of the input optical fiber array are:
The light enters the input lens array and is converted into a parallel light beam.

Next, the optical signals converted into the parallel light beams exit the input lens array and then enter the respective cells of the light beam shifter. Each optical signal incident on the light beam shifter is shifted by the above-mentioned shift function, or travels straight without receiving the shift action.

Each optical signal shifted or directly traveling in this manner exits the optical beam shifter and enters the output lens array, where it is collected and coupled to one end face of each optical fiber of the output optical fiber array. You. After being propagated through these optical fibers, the optical signals coupled to the optical fibers are output from the other end face as output light of the two-dimensional optical line switch.

According to claim (4), the optical signal emitted from each optical fiber of the input optical fiber array or the optical signal converted into a parallel light beam via the input lens array is the first signal.
The light beam shifter is shifted by the above-mentioned shift action or goes straight without receiving the shift action. Similarly, the second light beam shifter is also shifted by receiving the above-mentioned shift action or goes straight without receiving the shift action, but the shift direction is as follows.
The light beam is shifted in a direction having an angle of 90 degrees with respect to the shift direction of the first light beam shifter.

According to claim (5), the optical signal emitted from each optical fiber of the input optical fiber array or the optical signal converted into a parallel light beam via the input lens array is the first signal.
The first light beam shifter receives the shift action and
Is shifted in the direction of the center line of the light beam shifter, or travels straight as it is without undergoing the shifting action. Similarly, the second light beam shifter is also shifted by receiving the above-mentioned shift action or goes straight without receiving the shift action, but its shift direction is at an angle of 90 degrees with respect to the shift direction of the first light beam shifter. Is shifted in the direction with.

According to claim (6), an optical signal emitted from each optical fiber of the input optical fiber array or an optical signal converted into a parallel light beam via the input lens array performs the above-mentioned shift operation by the optical beam shifter. The vehicle is shifted in response to the vehicle, or travels straight without being affected by the shift operation.
At this time, the light beam shifter shifts the incident optical signal so as to spiral toward a central point in a certain direction.

According to claim (7), an optical signal emitted from each optical fiber of the input optical fiber array or an optical signal converted into a parallel light beam via the input lens array is subjected to the above-mentioned shift action by an optical beam shifter. The vehicle is shifted in response to the vehicle, or travels straight without being affected by the shift operation.
At this time, the light beam shifter shifts the incident optical signal linearly and toward the center thereof.

According to claim (8), an optical signal emitted from each optical fiber of the input optical fiber array or an optical signal converted into a parallel light beam via the input lens array performs the above-mentioned shift operation by the optical beam shifter. The vehicle is shifted in response to the vehicle, or travels straight without being affected by the shift operation.
At this time, the light beam shifter shifts the incident optical signal by a distance of one cell or a plurality of cells.

According to claim (9), an optical signal emitted from each optical fiber of the input optical fiber array or an optical signal converted into a parallel light beam through the input lens array is subjected to the above-mentioned shift operation by the optical beam shifter. And the vehicle goes straight without being shifted. At this time, the light beam shifter shifts the incident optical signal by a distance corresponding to a power-of-two cell.

According to claim (10), each light beam that has been shifted by receiving the shift action by one light beam shifter, or that has traveled straight without undergoing the shift action,
The expansion of the diameter of the lens array is suppressed, and the light is incident on the next-stage light beam shifter.

Further, according to claim (11), the optical signal emitted from each optical fiber of the input optical fiber array or the optical signal converted into a parallel light beam via the input lens array is incident on the polarization splitting means, and The light is separated into two orthogonal polarization components. Of these separated polarization components, one polarization component goes straight as it is without being affected by the shift action, and the other polarization component is shifted by a predetermined number of cells. Further, one of the polarized components that have gone straight and shifted has a polarization direction rotated by 90 degrees,
Thereby, the polarization directions of the two are aligned.

As described above, each of the two optical signal components separated by the polarization separating means and having the polarization direction aligned is incident on each cell of the light beam shifter. In the light beam shifter, these two optical signal components are respectively subjected to a shift operation, or go straight without being subjected to the shift operation, and are moved from a cell at a position apart from the final stage light beam shifter by a predetermined number of cells. Emit.

The two outgoing lights emitted from this light beam shifter then enter the polarization combining means, and one of the outgoing lights has a polarization direction
Rotated 90 degrees. Further, one of the light subjected to the rotation action and the light not subjected to the rotation action is shifted by a predetermined number of cells, and the two lights are combined. This combined light is incident on the optical fiber of the output optical fiber array directly or via an output lens array, propagates through the optical fiber, and is output as output light of the two-dimensional optical concentrator switch.

(Embodiment) FIG. 1 shows a first embodiment of a two-dimensional optical concentrator switch according to the present invention.
FIG. 3 is a configuration diagram showing an example of the embodiment. In FIG. 1, reference numeral 11 denotes an input optical fiber array, 12 denotes an input lens array, 13 denotes a light beam shifter group, 14 denotes an output lens array, and 15 denotes an output optical fiber array.

The optical signal (or also referred to as a light beam) in this embodiment described below means that a certain level of light is used as a carrier,
This is modulated by information (either analog or digital) (a known modulation method such as intensity, amplitude, frequency, phase, pulse position, etc.). When used, the average optical power is a positive value. It is assumed that the average optical power is zero or a value close to zero (a value sufficiently smaller than that in use). Also, the polarization direction of the input light beam is linearly polarized light,
In addition, it is assumed that the polarization directions of all the light beams are the same.

The input optical fiber array 11 has 25 optical fibers FB
They are arranged in a matrix of 5 rows and 5 columns.

The input lens array 12 is configured by, for example, arranging 25 single lenses (small lenses and rod lenses) LN in a matrix of 5 rows and 5 columns. In addition, these lenses LN
Are arranged so as to face the emission end faces of the optical fibers FB of the input optical fiber array 11, respectively, and convert the emission light from the facing optical fiber emission end faces into parallel light beams.

The light beam shifter group 13 includes, as shown in FIG. 4A, 25 shift cells SC having a function of shifting incident light in the (−) X direction in the coordinate system set in FIG.
An x-direction light beam shifter (for example, 13-1, 13-2) in which (x) is arranged in a matrix of 5 rows and 5 columns, and incident light in the (-) Y direction as shown in FIG. The y-direction light beam shifters (for example,... 13-n) in which 25 shift cells SC (y) having the function of shifting the data are arranged in a matrix of 5 rows and 5 columns are arranged in multiple stages.

Further, the light beam shifter 13-1 is connected to each shift cell SC.
Are disposed so as to face the respective lenses LN of the input lens array 12, and the remaining light beam shifters 13-2 to 13-
n is arranged such that the preceding or succeeding shift cell and the own-stage shift cell face each other.

FIG. 5 is a configuration diagram of the light beam shifter 13-i (where 1 ≦ i ≦ n). FIG. 5 (a) is a perspective view showing the light incident side, and FIG. It is sectional drawing (hatching is abbreviate | omitted for the simplification of drawing) of the direction of the AA arrow of FIG.

In FIG. 5, reference numeral 131 denotes a birefringent plate, which is made of, for example, a uniaxial crystal such as calcite. This birefringent plate 131 is
Of the incident light beam OB, an ordinary ray (a ray that obeys the "rule of refraction" in the birefringent plate) is allowed to go straight as indicated by an arrow OR in FIG. In the plate, "rays not obeying the law of refraction" are propagated obliquely as shown by an arrow ER in FIG. 5 (b), and emitted from the adjacent shift cell SC in a direction parallel to the z-axis. The light is emitted as it propagates.

Reference numeral 132 denotes a polarization control element, which is made of, for example, a twisted nematic liquid crystal or an electro-optic crystal used for a display device or the like. When an electric signal (having a predetermined level of voltage value) is supplied (applied), the polarization control element 132 rotates the polarization plane of incident light by 90 degrees, and when no voltage is applied, enters The light is emitted while maintaining the polarization plane of the light.

Reference numeral 133 denotes a light receiving / processing circuit, for example, as shown in FIG. 6, which includes light receiving processing units 133a and 133b separated at a substantially central portion, and has a polarization plane in the x direction on the light receiving processing unit 133a. The polarizing plate 134a that transmits only the light beam OB is
Polarizing plates 134b that transmit only the light beam OB having a polarization plane in the y direction are arranged on 3b. Further, a window 135 is formed substantially at the center of the light receiving / processing circuit 133.

Actually, these light receiving processing units 133a and 133b are the polarization control elements 1
In the case where 32 is formed of liquid crystal, for example, the periphery of the window 135 is formed of a thin-film amorphous silicon solar cell, and a light receiving (electric) signal is generated when a light beam having an average light power of a positive value is received. A light receiving element is provided, and a processing circuit is formed in the remaining portion by using an electronic circuit forming technique.

This processing circuit recognizes the light reception of the light beam and the polarization direction of the received light beam based on the presence or absence of the light receiving signal of the light receiving element, and also recognizes FIG. 7 and FIG.
Based on the algorithm shown in the figure, after confirming the usage status of the adjacent cells, application or non-application of a voltage (drive signal) to the polarization control element 132, that is, whether to shift the incident light beam or go straight on as it is The control is performed.

The light receiving / processing circuit 133 having such a configuration, the polarization control element 1
Each shift cell SC is constituted by 32 and the birefringent plate 131.

Next, the shift cell SC (specifically, the light receiving / processing circuit 13
The control operation for determining the output route in 3) will be described with reference to FIGS. 7 and 8. FIG. 7 is a flowchart for explaining the output route determination algorithm in the shift cell, and FIG. 8 is a diagram showing the configuration of the output route determination condition table TAB of the own shift cell.

First, in step S1, the light receiving / processing circuit 133
The light receiving signal from the light receiving element described above changes from on to off,
Further, it is determined whether or not the input has changed from off to on, that is, whether or not the own input has changed.

Next, if it is determined in step S1 that the own input has changed, in step S2, the direction of the input change changes from a state with the input light beam (ON) to a state without input (OFF). It is determined whether or not it has been performed.

In step S2, if it is determined that the state has changed from the state with the input light beam to the state without the input, it is determined that the communication has been completed, and in step S3, the output route of the own cell is `` straight ahead ''. (Stop application of voltage to the polarization control element 132), and return to step S1.

On the other hand, if it is determined in step S2 that there is no change from the state with the input light beam to the state without input, it is determined that communication has been started, and in step S4, the table in FIG. Polarization control element 1 based on TAB
The state of application of voltage to 32 and the state of non-application of voltage are appropriately selected, the output path of the own cell is determined, and the process returns to step S1.

In the case where the route of the light beam is controlled by the above algorithm, in the state shown by "*" in FIG. 8, that is, when the light beam is incident on a certain shift cell SC, it cannot go straight or shift. A state of "block" may occur.

At this time, in the configuration shown in FIG. 5, a light beam that has been incident later is mixed with another light beam that is already in use. Therefore, when a block becomes a problem, when a block occurs, it is necessary to block the light beam that later caused the block so that it does not proceed to the next stage. is there.

As a blocking method for this block, for example, in the light beam shifter 13-i shown in FIG.
Means for returning the shifted outgoing light beam from the extraordinary ray to an ordinary ray on the light exit side of the block 131; means for converting a later incident light beam into an extraordinary ray when detecting a block; And a means for blocking the extraordinary ray by passing the light.

Specifically, the birefringent plate 131 is described in the order of the light receiving / processing circuit capable of detecting the polarization direction (the same configuration as the configuration in FIG. 6), the polarization control element, and the polarizing plate (analyzer). (Not shown).

With such a configuration, at normal time, that is, at the time of non-shift, the output light beam level of the birefringent plate 131 is monitored by the light receiving / processing circuit, and at the time of extraordinary light, that is, at the time of shift, by the polarization control element. By converting into an ordinary ray, the light beam always passes through the polarizer and reaches the next light beam shifter. Also, when the ordinary ray and the extraordinary ray are received at the same time, that is, at the time of blocking, if the state of the polarization control element is maintained in the state immediately before the occurrence of the block,
The light beam that enters later becomes an extraordinary ray, enters the polarizing plate, and is blocked.

The output lens array 14 corresponds to the input lens array 12 described above.
Similarly to the above, for example, nine single lenses (small lenses and rod lenses) LN are arranged in a matrix of 3 rows and 3 columns. Each of these lenses LN is located on the light emission side of the last stage light beam shifter 13-n of the light beam shifter group 13, and has nine shift cells at the lower left corner in FIG.
The output light from the shift cell SC is coupled to one end face of each optical fiber FB of the output optical fiber array 15.

The output optical fiber array 15 has nine optical fibers FB
They are arranged in a matrix with three rows and three columns. One end faces of these optical fibers FB are arranged so as to face the light emission side of each lens LN of the output lens array.

Next, the operation of the above configuration will be described with reference to FIG. 5 to FIG.

In FIG. 9, the light beam shifter group shown in FIG.
The number of 13 light beam shifters is 4 (n = 4), and the light beam shifters 13-1 and 13-2 are constituted by x-direction light beam shifters shown in FIG. 4A, and the light beam shifters 13-3 and 13 -4 is constituted by the y-direction light beam shifter shown in FIG. 4 (b). For the sake of simplicity, the optical signal S is an ordinary ray (linearly polarized light). As shown in FIG. 9, the optical signal S enters one optical fiber FBI11 of the input optical fiber array 11, and the optical signal S Final optical fiber array 15
The operation output from the optical fiber FB011 will be described as an example.

The optical signal S incident on the optical fiber FBI11 of the input optical fiber array 11 propagates through the optical fiber FBI11, and then exits from the exit end face thereof, and is output from the lens LN11 of the input lens array 12.
Incident on. The optical signal S incident on the lens LN11 is converted here into a parallel light beam OB.

The optical signal S converted into the parallel light beam OB is transmitted to the lens LN11.
Then, as the light beam OB propagates in the z-axis direction, the diameter of the light beam OB increases due to the light diffraction phenomenon. In this state, the light beam OB enters the shift cell SC11 of the first-stage light beam shifter 13-1 in the light beam shifter group 13. I do. At this time, the light beam OB is applied to the window 135 of the shift cell SC11 (FIG. 5).
However, as described above, the diameter of the light beam is larger than the diameter of the window 135 due to diffraction. For this reason,
A part of the light beam OB is absorbed by the light receiving / processing circuit 133 (received by a light receiving element, not shown).

When the average power level of the received light beam OB takes a positive value, the light receiving / processing circuit 133 determines that the light beam has entered the shift cell SC11, and checks the polarization direction of the light beam OB. According to the algorithm shown in FIG. 7 and FIG. 8, after the usage status of the adjacent shift cell SC12 in the (-) direction is confirmed, the application of the drive signal to the polarization control element 132 and the non-application thereof are controlled.

At this time, when it is determined that the adjacent shift cell SC12 is in use, the light receiving / processing circuit 133
No drive signal is applied to 32. As a result, the light beam OB incident on the polarization control element 132 through the window 135 is not affected by the rotation of the polarization plane, and remains as an ordinary ray, and the birefringent plate
It is incident on 131.

Since the light beam OB incident on the birefringent plate 131 is an ordinary ray, it goes straight as indicated by an arrow OR in FIG. 5A, exits from the shift cell SC11, and is shifted to the next stage light beam shifter. 13-2.

On the other hand, when it is determined that the adjacent shift cell SC12 is unused, the light receiving / processing circuit 133 sets the polarization control element 132
Is applied with a drive signal. As a result, the light beam OB that has entered the polarization control element 132 through the window 135 is incident on the birefringent plate 131 with the polarization plane rotated by 90 degrees (as an extraordinary ray).

Since the light beam OB that has entered the birefringent plate 131 is an extraordinary ray, it propagates obliquely through the birefringent plate 131 and exits from the adjacent shift cell SC12, as shown in FIG. 5 (b). At the time of this emission, the propagation direction of the light beam OB is returned to a direction parallel to the z-axis.

The light beam OB emitted from the shift cell SC12 due to such a shift operation enters the shift cell SC12 of the next stage light beam shifter 13-2. Also in this shift cell SC12, in the same manner as described above, it is determined whether the vehicle is going straight (non-shifted) or shifted according to the use state of the adjacent shift cell SC13.

Here, for example, when the adjacent shift cell SC13 is unused, the light beam OB is shifted from the shift cell SC12 to the shift cell SC13 under the same shift action as described above, and the light beam OB of the next stage light beam shifter 13-3 is changed. The light enters the shift cell SC13.

In the shift cell SC13 of the y-direction light beam shifter 13-3, as described above, with the incidence of the light beam OB,
(-) It is determined whether to shift straight (non-shift) or shift according to the use state of the adjacent shift cell SC23 in the y direction.

Here, for example, assuming that the adjacent shift cell SC23 is unused, the light beam OB is shifted in the (-) y direction as shown in FIG.
Is shifted to the shift cell SC23, and enters the shift cell SC23 of the shift cell SC13-4 of the light beam shifter 13-4 at the last stage.

In the shift cell SC23 of the light beam shifter 13-4,
With the incidence of the light beam OB, as described above, (-) y
It is determined whether to shift straight (non-shift) or shift according to the use state of the shift cell SC33 adjacent in the direction.

Here, for example, assuming that the adjacent shift cell SC33 is unused, the light beam OB becomes (-) y similarly to the above.
Shift cell from shift cell SC23 subject to shift action in the direction
The light is shifted to SC33 and is incident on the lens LN11 of the output lens array 14.

The light beam OB incident on the lens LN11 is condensed and coupled to the light incident end face of the optical fiber FB011 of the output optical fiber array 15. As a result, the optical fiber FB011
After the light propagates through the optical fiber FB011 incident on the optical line switch, the light is output as an output optical signal S of the optical concentrator switch from the light emitting end face.

In the above description, the operation for one optical signal has been described. However, actually, even when a plurality of optical signals are input to the optical condensing switch at the same time, the same operation as described above is performed. This is performed in each shift cell SC of the light beam shifters 13-1 to 13-4.

10A and 10B are output state transition diagrams of the respective light beam shifters. FIG. 10A shows a state at the time of input to the light beam shifter group 13, and FIGS. 10B and 10C show x-direction light beam shifters. The output states of 13-1 and 13-2 are shown, and (d) and (e) of the same figure show the output states of the y-direction light beam shifters 13-3 and 13-4, respectively. In FIG. 10, “●” indicates a state where an optical signal is present, and “「 ”indicates a state where no optical signal is present.

As can be seen from FIG. 10, the plurality of optical signals input simultaneously are the light beam shifters 13-1 to 13-1 of the light beam shifter group 13.
By sequentially passing through 13-4, the light is finally collected at the lower left corner (corresponding to the output optical fiber array) in FIG. 10 and output.

As described above, according to the first embodiment, each of the input optical fiber array 11, the input lens array 12, the light beam shifter group 13, the output lens array 14, and the output optical fiber array 15 arranged in a two-dimensional array Since the optical components are arranged in multiple stages in the order shown, the mounting density can be greatly improved compared to the conventional optical line switch in which multiple waveguide type optical switches are connected. Can be realized.

Actually, as the specific dimensions of the two-dimensional optical concentrator switch, for example, calcite is used as the birefringent plate 131, and the input 102
When a 4 (32 × 32), output (8 × 8) optical concentrator switch is configured, by arranging the shift cells SC at intervals of about 0.6 mm, a size of about 20 mm × 20 mm × 40 mm (about 160 cm ³ ) is obtained. Can be realized. This is about 1/14 in volume as compared with the case of using a conventional waveguide type optical switch (about 2200 cm ³ ).

FIG. 11 shows a second example of the two-dimensional optical concentrator switch according to the present invention.
FIG. 3 is a configuration diagram showing an example of the embodiment. The difference between the second embodiment and the specific configuration example of the first embodiment shown in FIG.
This is because the positions of the x-direction light beam shifter 13-2 and the y-direction light beam shifter 13-3 in the second stage of the light beam shifter group 13 are interchanged.

In the second embodiment having such a configuration, the first
The same effect as that of the embodiment can be obtained.

FIG. 12 is a third view of the two-dimensional optical concentrator switch according to the present invention.
FIG. 3 is a configuration diagram showing an example of the embodiment. The difference between the third embodiment and the first embodiment shown in FIG.
, 13-n of each of the thirteen light beam shifters 13-1, 13-2,..., 13-n has the same configuration and function as the input lens array 12, and suppresses the spread of the light beam OB. That is, the lens arrays 20-1, 20-2,... Are inserted.

With such a configuration, the light beam shifter 13
This is effective when the thickness in the z direction (light propagation direction) of −1,... Is large (for example, when the shift distance is long) and the spread of the diameter of the light beam OB due to diffraction cannot be ignored.

At this time, there is a slight increase in the size due to the insertion of the interstage lens arrays 20-1, 20-2,..., But these are almost negligible as compared with the size of the conventional optical concentrator switch.

In the above-described first to third embodiments, a plurality of single lenses (small lenses or rod lenses) are used as a lens array as an input / output and inter-stage lens array in a matrix (two-dimensional).
The configuration example is an arrangement in a shape, but the invention is not limited to this. For example, an integrally formed two-dimensional array lens array obtained by spatially controlling the refractive index of a glass material can be applied. It is.

Further, the order in which the x-direction light beam shifter and the y-direction light beam shifter are arranged in the light beam shifter group 13 is not limited to the order shown in FIG. 2 or FIG. 11, and it is needless to say that the order can be set arbitrarily. Nor.

Further, the shift cells constituting the light beam shifter have only the same shift direction (only the x direction or the y direction) in the same light beam shifter, but the present invention is not limited to this.

For example, as shown in FIGS. 13 (a) and (b), an x-direction light beam shifter shifts in the (−) x direction in the right half and in the x direction in the left half, and FIG. The light beam group may be finally collected at the center on the xy plane by a configuration in which a light beam shifter that shifts in the (−) y direction in the upper half and the y direction in the lower half is combined.

Further, as shown in FIGS. 13 (c) and (d), a spiral type (FIG. 13 (c)) or a centripetal type (FIG. 13 (c)) which gradually collects the light beam from the outer periphery toward the center. ((D) in the figure)
May be used.

Furthermore, in the above-described shift cell SC, the shift distance is one cell, but is not limited to this, and a plurality of cells per stage, for example, 2 ⁱ (i = 1 to n)
May be shifted over the cells.

For example, as shown in FIG. 14, each light beam shifter 13a
-1,13a-2, ..., 13a- n-1,13a-n are each one stage per, 2 ^n-1 (cell), 2 ^n-2 (cell), ... 2 ¹ (cells) and 2 ⁰
By adopting a configuration in which the shift is performed by (cell), the number of stages of the light beam shifter can be greatly reduced as compared with the case where the shift is performed by one cell per one stage of the light beam shifter, and furthermore, an advantage of further downsizing can be achieved. There is.

In the first to third embodiments, the polarization state of the input light is linearly polarized and the polarization directions of all the light beams are the same. If not satisfied, the method of inputting the polarization directions of all the light beams to the light beam shifter, or the method of separating the polarization in two orthogonal directions and inputting each separately to the light beam shifter, Either method may be adopted.

The former is a method of providing a function of monitoring and adjusting the polarization state corresponding to all the light beams. When the input light is elliptically polarized light, it is returned to linearly polarized light and rotated to a predetermined polarization direction. Such processing is performed independently for each input light.

On the other hand, in the latter method using polarization separation, a birefringent plate and a polarization rotation element (λ / 2 plate or liquid crystal) array are arranged before and after the input / output lens array, and the input light is separated into ordinary rays and extraordinary rays. Shift processing is performed for each light beam, and these are combined at a stage prior to the output lens array.

FIG. 15 is a block diagram showing a fourth embodiment of the secondary optical concentrator switch according to the present invention, showing a configuration in which the above-described polarization separation method is employed.

In FIG. 15, reference numeral 11 denotes an input optical fiber array, 12 denotes an input lens array, 13 denotes a light beam shifter group, 14 denotes an output lens array, and 15 denotes an output optical fiber array. These structures and functions are the same as those shown in FIG. 1. In addition to these structural requirements, as described above, the light exit side of the input lens array 12 and the first-stage light beam shifter 13- A birefringent plate 131-1 and a half-wavelength (λ / 2) or polarization rotator made of liquid crystal between one light incident side.
Insert the polarization rotation element array 30-1 in which PR is arrayed,
Moreover, the light beam shifter 13 at the last stage of the light beam shifter group 13
A two-dimensional optical concentrator switch is constructed by inserting the polarization rotator array 30-2 and the birefringent plate 131-2 between the -n light emitting side and the output lens array 14. Further, in FIG. 15, the solid line indicates the trajectory of the ordinary ray, and the wavy line indicates the trajectory of the extraordinary ray.

In such a configuration, the input optical fiber array 11
, The optical signal converted into a parallel light beam by the input lens array 12 is first separated into an ordinary ray and an extraordinary ray by the birefringent plate 131-1. The separated extraordinary ray propagates through the birefringent plate 131-1 in the same manner as shown in FIG. 5B, shifts by one cell, and exits the birefringent plate 131-1. On the other hand, the ordinary ray goes straight out of the birefringent plate 131-1 and exits.

Thus, the ordinary ray and the extraordinary ray that have been separated and emitted from the birefringent plate 131-1 then enter the polarization rotation element PR of the polarization rotation element array 30-1.
The extraordinary ray incident on the polarization rotator PR is converted into an ordinary ray, and the ordinary ray is incident on shift cells adjacent to each other of the light beam shifter 13-1 without being subjected to a conversion action.

At this time, each light beam shifter 13 of the light beam shifter group 13
By setting the shift processing in -1,..., 13-n so that each light beam always shifts side by side, the polarization rotator array 30-2 on the output side and the birefringent plate 13
By passing through 1-2, one light beam can be combined again and output.

(Effects of the Invention) As described above, according to claim (1), since the two-dimensionally arrayed optical components are connected in multiple stages,
Compared to the case where a conventional optical waveguide switch corresponding to a one-dimensional array is connected in multiple stages to form an optical concentrator switch, the mounting density can be greatly increased, and a compact and economical two-dimensional optical concentrator switch can be realized. It is possible to arbitrarily set whether to shift the incident light of the light beam shifter or to proceed straight as it is, so that efficient switching can be performed.

According to claim (2), in addition to the effect of claim (1), further accurate switching control can be performed, and a highly accurate and efficient two-dimensional optical line switch can be provided.

According to the third aspect of the present invention, since the input lens array and the output lens array are provided, the light beam can be efficiently transmitted between the input optical fiber array and the optical beam shifter and between the optical beam shifter and the output optical fiber array. Can be combined.

According to claim (4), the provision of the two types of light beam shifters whose shift directions are different from each other by 90 degrees enables the light beam group to be collected at an arbitrary position.

According to claim (5), by providing two types of light beam shifters that shift the light beam toward the center line and have different shift directions by 90 degrees, the light beam group can be efficiently collected near the center. it can.

Further, according to claim (6) or (7), the provision of the light beam shifter for collecting the light beam toward the center point allows the light beam group to be efficiently collected near the center.

Further, according to claim (8) or (9), in addition to the above-described effects, there is an advantage that the number of stages of the light beam shifter can be reduced, and further downsizing can be achieved.

According to claim (10), for example, it is effective when the thickness of the light beam shifter in the light propagation direction is large and the shift distance is long, and when the spread of the diameter of the light beam due to diffraction during propagation cannot be ignored. Therefore, the influence of the size of the light beam shifter and the like can be suppressed, and the versatility is excellent.

According to claim (11), the switching can be performed with high accuracy and high efficiency without being affected by the polarization state of the input light.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a two-dimensional optical concentrator switch according to the present invention, FIG. 2 is a configuration diagram of a conventional optical concentrator switch, and FIG. 3 is a specific example of a conventional optical concentrator switch. FIG. 4 is a diagram for explaining a shift direction of a light beam in the light beam shifter according to the present invention, FIG. 5 is a configuration diagram of the light beam shifter according to the present invention, and FIG. FIG. 7 is an explanatory diagram of the configuration of a processing circuit, FIG. 7 is a flowchart for explaining an output route determination algorithm in a shift cell according to the present invention, FIG. FIG. 9 is a diagram for explaining the operation of FIG.
FIG. 10 is a diagram showing the output state transition of a plurality of input lights by the respective light beam shifters in FIG. 1, FIG. 11 is a configuration diagram showing a second embodiment of the two-dimensional optical concentrator switch according to the present invention, and FIG. FIG. 13 is a configuration diagram showing a third embodiment of the two-dimensional optical concentrator switch according to the present invention, FIG. 13 is a diagram showing another type of light beam shift direction in the light beam shifter according to the present invention, and FIG. FIG. 15 is a diagram showing a configuration example in which a plurality of cells are shifted per stage of the light beam shifter. FIG. 15 is a configuration diagram showing a fourth embodiment of the two-dimensional optical line switch according to the present invention. In the figure, 11: input optical fiber array, 12: input lens array, 13: light beam shifter group, 13-1 to 13-n, 13a
-1 to 13a-n: light beam shifters, 131, 131-1, 131-
2 Birefringent plate, 132 Polarization control element, 133
Processing circuit, 134a, 134b: Polarizer, 135: Window, 14: Output lens array, 15: Output optical fiber array, 20-1,
20-2: Interstage lens array, 30-1, 30-2: Polarization rotating element array, FB: Optical fiber, LN: Lens, SC ...
… Shift cell, PR …… Polarization rotation element.

Claims (11)

(57) [Claims] 1. A two-dimensional optical concentrator switch accommodating an optical fiber line, comprising: an input optical fiber array in which a plurality of optical fibers to which respective optical signals propagated through the optical fiber line are incident are two-dimensionally arranged; The output light of each optical fiber of the input optical fiber array is made up of a plurality of cells which travel straight for each output light or individually shift at a predetermined distance in a direction perpendicular to the propagation direction, and each cell is an electric signal. A polarization control element for controlling the polarization direction of the incident light according to the supply state, a birefringent plate disposed on the light incident side or the light emission side of the polarization control element, and a polarization control element according to the light reception state of the incident light beam At least one light beam shifter comprising a light receiving / processing circuit for controlling a supply state of an electric signal to the light beam, and each light emitted from the light beam shifter enters one end surface thereof. A plurality of two-dimensional optical concentrator switch, characterized in that the optical fiber and an output optical fiber array in which two-dimensionally to. 2. A two-dimensional optical concentrator switch accommodating an optical fiber line, comprising: an input optical fiber array in which a plurality of optical fibers to which respective optical signals propagated through the optical fiber line are incident are two-dimensionally arranged; The output light of each optical fiber of the input optical fiber array is made up of a plurality of cells which travel straight for each output light or individually shift at a predetermined distance in a direction perpendicular to the propagation direction, and each cell is an electric signal. A polarization control element for controlling the polarization direction of the incident light according to the supply state, a birefringent plate arranged on the light incident side or the light emission side of the polarization control element, a light receiving state of the incident light beam, and use of another cell At least one light beam shifter comprising: a light receiving / processing circuit for controlling a state of supplying an electric signal to the polarization control element according to a state; and each light emitted from the light beam shifter. A plurality of two-dimensional optical concentrator switch, characterized in that the optical fiber and an output optical fiber array in which two-dimensionally incident respectively on one end face. 3. An input lens array for converting light emitted from each optical fiber of the input optical fiber array into parallel light beams, and inputting these light beams to the light beam shifter, on a light output side of the input optical fiber array. And an output lens array arranged between the light incident side of the light beam shifter and coupling each output light beam of the light beam shifter to one end surface of each optical fiber of the output optical fiber array. The two-dimensional optical concentrator switch according to claim 1 or 2, wherein the two-dimensional optical concentrator switch is disposed between a first side and a light incident side of the output optical fiber array. 4. A first light beam shifter in which the shift direction is the same for all the incident light beams, and a first light beam shifter in which the first light beam shifter is rotated by 90 degrees about the light beam propagation direction. The two-dimensional light beam shifter according to any one of claims (1) to (3), further comprising two light beam shifters, wherein the first and second light beam shifters are arranged alternately in one or more stages or in multiple stages by an arbitrary combination. Light concentrator switch. 5. A first light beam shifter whose shift directions are opposite to each other so as to collect light beams from both sides toward the center line, and the first light beam shifter is moved by 90 degrees with respect to the light beam propagation direction as an axis. A second light beam shifter in a rotated shift direction is provided, and the first and second light beam shifters are arranged in one or a plurality of stages alternately or in multiple stages by an arbitrary combination. The two-dimensional optical concentrator switch according to any of the above. 6. The two-dimensional optical concentrator according to claim 1, further comprising a light beam shifter that spirally shifts the light beam from the outer periphery so as to collect the light beam toward the center point. switch. 7. A light beam shifter for shifting a light beam linearly from an outer peripheral portion toward a center so as to collect the light beam toward a center point.
The two-dimensional optical concentrator switch according to any of the above. 8. The two-dimensional optical concentrator according to claim 1, further comprising an optical beam shifter having a shift distance of one cell or a plurality of cells. 9. The two-dimensional optical line switch according to claim 8, further comprising an optical beam shifter whose shift distance is a power-of-two cell. 10. The two-dimensional optical concentrator switch according to claim 1, wherein a lens array for suppressing the spread of the light beam is arranged between the stages of the light beam shifter. 11. A means for separating incident light into two orthogonal polarization components on the light incident side of a first stage light beam shifter, causing one of the separated components to go straight, and shifting the other by a predetermined number of cells. And a means for rotating one polarization direction of the emitted light of the means by 90 degrees to align the polarization directions of both, and the polarization separation means is arranged, and the light emission side of the final stage light beam shifter, A means for rotating one polarization direction of one of light emitted from one shift cell of the light beam shifter and light emitted from a cell separated by a predetermined number of cells by 90 degrees, and one of the light emitted from the means is rotated by a predetermined amount. The two-dimensional optical concentrator switch according to any one of claims 1 to 10, further comprising a polarization combining unit that shifts by the number of cells and combines the two outgoing lights.