JP3235741B2 - Spatial light switch device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

(Contents) Industrial application field Conventional technology Problems to be solved by the invention Means for solving the problem Actions Embodiment (a) Description of first embodiment (FIGS. 1 to 5) (b) Description of the second embodiment (FIGS. 6 to 9) (c) Description of the third embodiment (FIGS. 10 to 13) (d) Description of the fourth embodiment (FIGS. 15 to 17) (e) Fifth Description of the embodiment (FIGS. 18 to 22) (f) Description of the sixth embodiment (FIGS. 23 to 24) (g) Others (FIG. 14)

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spatial light switch device for variably connecting one-dimensional or two-dimensional spatially multiplexed optical signals. In recent years, it has become necessary to transfer large-capacity image data of about 4 Kbytes to about 6 Mbytes through an ultra-high-speed transmission line of about 10 Gbit / sec.
It has been proposed to use a spatial light switch device as a variably connectable cross-connect device in such a case.

In addition, the spatial optical switch device has attracted attention as a device that can be used for realizing a subsystem such as a connection network between processors and memories of a parallel processing computer and a multistage switch of an ATM switch on an optical communication path. ing.

[0004]

2. Description of the Related Art Conventionally, as this kind of spatial optical switch device, for example, APPLIED OPTICS / Vo
l. 29, No. 26 pp3848-3854 / 10
As disclosed in Setmber 1990, an optical switch combining a polarization control element using liquid crystal and a polarization separation function using a hologram has been proposed.

An optical switch combining a polarization controlling surface element such as a liquid crystal panel receiving a plane input and a routing element using a birefringent crystal has also been proposed (Photonic Switching II: P).
rosedings of the Internet
ionic Topical Meeting, Kob
e, Japan, April 12-14, 199
0).

Further, a polarization separator, a polarization controller, and a λ / 4
First reflection block composed of a plate and an optical path changing element, λ / 4
A spatial light switch combining a plate and a second reflecting block including a reflecting mirror has been proposed (Photonic).
Switching Vol. 8: Proceedi
ngs of the InternationalTo
pical Meeting, Salt Lake C
ity Utah, March 6-8, 1991).

Further, there has been proposed an optical crossbar switch arranged in a matrix on a waveguide formed on a dielectric (LiNbO ₃ ) substrate.

[0008]

However, the conventional spatial light switch device as described above has a problem that its structure is complicated, that it is expensive, that a polishing step is required, and that the number of manufacturing steps is increased. . Also, a polarization separator,
In a spatial light switch combining a polarization controller, a first reflection block including a λ / 4 plate and a light path changing element, and a spatial light switch including a second reflection block including a λ / 4 plate and a reflection mirror, a prism array is used as the light path changing element. However, the size of the prism array increases with the input of a multi-channel beam, and the insertion loss and crosstalk may increase due to the increase in the optical path difference between the optical path and the beam path. There is a problem that only a two-output configuration can be used.

There is another problem that it is impossible to handle a two-dimensional signal (area input).

The spatial light switch device of the present invention has been made in view of the above-mentioned problems, and can easily adopt a multi-input multi-output configuration, and can reduce insertion loss and crosstalk. The purpose is to do. Also,
It is an object of the present invention to provide a spatial light switch device having common components so as to reduce the number of types of parts required for manufacturing.

Further, the spatial light switch device of the present invention comprises:
It is another object of the present invention to reduce the channel interval. Another object is to facilitate positioning for manufacturing or mounting. Further, the spatial light switch device of the present invention can realize a polarization control algorithm for realizing non-blocking cross-connect routing using a two-input two-output optical switch having polarization control means and optical path shift means as a basic switch. With the goal.

[0012]

In order to achieve the above-mentioned object, a spatial light switch device according to the present invention is provided in one of two optical axes parallel to each other in one of two directions orthogonal to a linear polarization plane. The polarization control means for switching to and the light along the two optical axes from the polarization control means are respectively input, and the light is output in the bypass mode along the corresponding optical axes, and along one of the optical axes. Light path shifting means for outputting light in an exchange mode in which the light flux is shifted by diffraction so that the propagating light flux propagates along the other optical axis in one of the two polarization directions.
By providing a two-input two-output optical switch and arranging a plurality of two-input two-output optical switches such that two mutually parallel optical axes of the two-input two-output optical switch are parallel to each other, A spatial optical switch step is formed, and the spatial optical switch steps are stacked by a required number of stages to constitute a multi-input multi-output spatial optical switch (claim 1).

Further, the spatial light switch device according to the present invention comprises:
The polarization control means is configured as a means for controlling the polarization state by sandwiching the liquid crystal between transparent electrodes and applying a voltage, and the polarization control means is segmented according to the channel arrangement so that each can be independently controlled. It is formed integrally (claim 2).

Further, in the spatial light switch device of the present invention, the optical path shifting means includes a first diffraction grating layer and a second diffraction grating layer which are arranged in parallel at a distance from each other, and the diffraction grating of each layer is provided. Have different lattice vectors 2
The first diffraction grating layer and the second diffraction grating layer shift the beam for S-polarized light, and shift the beam for P-polarized light. In a configuration in which both the first diffraction grating layer and the second diffraction grating layer are transmitted, the first diffraction grating layer and the second diffraction grating layer each have two plane diffraction grating segment pairs having different grating vectors. Are arranged two-dimensionally, and the beam shift according to the polarization state is performed between adjacent channels to constitute a multi-input multi-output spatial optical switch (Claim 3).

Further, the spatial light switch device according to the present invention comprises:
The optical path shifting means comprises a first diffraction grating layer and a second diffraction grating layer which are arranged in parallel at an interval from each other, and each of the diffraction gratings of each layer comprises two plane diffraction gratings having different grating vectors. And for S-polarized light:
The beam is shifted by being diffracted by the first diffraction grating layer and the second diffraction grating layer, and P-polarized light is transmitted through both the first diffraction grating layer and the second diffraction grating layer. In this configuration, the polarization control means, the first diffraction grating layer, and the second diffraction grating layer are integrally laminated without an air layer therebetween to form a spatial light switch step portion, and A multi-input, multi-output spatial optical switch is formed by integrally laminating a plurality of switch steps without interposing an air layer.

In the spatial light switch device of the present invention, the spatial light switch step on the light input side is provided with collimating means for converting incident light into parallel light, and the spatial light switch step on the light output side is provided on the light output side. And a light condensing means for converging the emitted light.

In order to achieve the above object, a spatial light switch device according to the present invention comprises two two-input two-output optical switches arranged in parallel so that their incident surfaces are parallel to each other. A four-input four-output spatial optical switch is formed by forming a stepped part and stacking the second spatial optical switch stepped part by 90 degrees with respect to the first spatial optical switch stepped part; (Claim 6).

Further, in order to achieve the above object, the spatial light switch device of the present invention comprises two two-input two-output optical switches which are arranged in parallel so that their incident surfaces are parallel to each other. A spatial optical switch device having a structure in which these spatial optical switch steps are superposed in four stages, wherein a first adjacent channel interval is d on the optical input surface, and channel 0 is (0, d). ), Channel 1 to (d,
d), channel 2 is (d, 2d), and channel 3 is (2,
d, 2d), channel 4 is (d, 0), channel 5 is (2d, 0), channel 6 is (2d, d), channel 7
Are arranged at (3d, d), and the first spatial optical switch stage section performs channel 0-channel 4, channel 1-channel 5, channel 2-channel 6, channel 3-channel 7
The second spatial optical switch stage and the third spatial optical switch stage respectively provide channel 0-channel 2, channel 1-channel 3, channel 4-channel 6, and channel 5-channel. 7, a beam shift structure between channels 0-channel 1, channel 2-channel 3, channel 4-channel 5, and channel 6-channel 7 is provided in the fourth spatial light switch stage. , An eight-input, eight-output banyan-network-type spatial optical switch (claim 7).

In the spatial light switch device of the present invention, means for rotating the polarization plane by 45 degrees is provided between the third spatial light switch step and the fourth spatial light switch step. (Claim 8). In order to achieve the above object, the spatial light switch device of the present invention is arranged so that two mutually parallel optical axes in the two-input two-output optical switch are parallel to each other. A spatial optical switch step is formed by arranging a plurality of two-output optical switches, and the spatial optical switch steps are stacked in 11 stages to form a spatial optical switch having an equivalent circuit structure of an 11-stage cross-banyan network. An apparatus, wherein at the light input surface, d
Is the adjacent channel interval, channel 0 is (0, 0), channel 1 is (0, -2d), and channel 2 is (2d,
0), channel 3 is (2d, -2d), channel 4 is (d, -d), channel 5 is (d, -3d), channel 6 is (3d, -d), and channel 7 is (3d, -d). 3d),
Channel 8 is (d, 0) and channel 9 is (d, -2).
d), channel 10 is (3d, 0), channel 11 is (3d, -2d), channel 12 is (0, -d), channel 13 is (0, -3d), and channel 14 is (2d, -2).
d), the channel 15 is arranged at the position (2d, -3d), and the first, fourth, seventh and tenth spatial optical switch stages have channels 0-2, 4-6, 1-3 and 5-7. , 8-10,1
2-14, 9-11, and 13-15 can be switched. In the second, fifth, eighth, and eleventh spatial light switch stages,
Channels 0-1, 4-5, 2-3, 6-7, 12-1
3, 8-9, 14-15, and 10-11 are configured to be switchable. In the third and ninth spatial optical switch stages, channels 0-4, 1-5, 2-6, 3-7, 8-12, 9-1
3, 10-14, and 11-15, and the sixth spatial optical switch stage has channel 0
-8,12-4,1-9,13-5,2-10,14-
6, 3-11, and 15-7 so as to be switchable.
Let B (I) be the I-th bit in binary notation of each node in each stage, FB (J) be the J-th bit in binary notation of the destination node, and PS be the The polarization is set to 0 for P-polarized light and 1 for S-polarized light, and SC is set to the polarization control switch state. In the first, fourth, seventh, and tenth spatial light switch stages, SC = PS XOR (NB (3) XOR FB (3 )) In the second, fifth, eighth and eleventh spatial optical switch stages, SC = PS XOR (NB (4) XOR FB (4)) In the third and ninth spatial optical switch stages, SC = PS XOR ( NB (2) XOR FB (2)) The sixth spatial light switch stage is characterized in that a polarization switch setting is given as SC = PS XOR (NB (1) XOR FB (1)) ( Claim 9).

Further, in order to achieve the above object, the spatial optical switch device of the present invention forms a spatial optical switch step by arranging a plurality of two-input, two-output optical switches. 9 is a spatial optical switch device having an equivalent circuit structure of a nine-stage extended deformed banyan network, wherein d is an adjacent channel interval, and channel 0 is (0,0), Channel 1 is set to (d,
-D), channel 2 at (0, -2d), channel 3 at (d, -3d), channel 4 at (2d, 0), channel 5 at (3d, -d), and channel 6 at (2d, -d). 2d),
Channel 7 is (3d, -3d), and channel 8 is (d, -3d).
0), channel 9 at (0, -d), channel 10 at (d, -2d), channel 11 at (0, -3d), channel 12 at (3d, 0), and channel 13 at (2d, -d).
d), channel 14 is (3d, -2d), channel 15
At the position of (2d, -3d), and channels 0-4, 1-5, 2-6,
3-7,8-12,9-13,10-14,11-15
And the second, third, seventh, and eighth spatial optical switch stages have channels 0-2, 1-3, and 4-.
6,5-7,9-11,8-10,13-15,12-
14, and the fourth and ninth spatial light switch stages have channels 0-1, 2-3, 4-5, and 6-, respectively.
7, 8-9, 10-11, 12-13, and 14-15 so as to be switchable. In the fifth spatial optical switch stage, channels 0-8, 1-9, 2-10, and 3- 11,4
NB (I) is the I-th bit of the binary representation of each node at each stage, and FB (J) is the destination. Node 2
The J-th bit in hexadecimal notation, PS is 0 for P-polarized light, 1 for S-polarized light, and SC
Let the polarization control switch state be: SC = PS XOR (NB (M) XOR FB (M)) in the first, third, fourth, sixth, ninth spatial light switch stages (M in the order of each stage) = 2,3,4,2,3,4) In the second and seventh spatial optical switch stages, SC = PS XOR (NB (3) XOR FB (3)) In the fifth spatial optical switch stage, A polarization switch setting is given as SC = PS XOR (NB (1) XOR FB (1)) (claim 10).

In order to achieve the above object, the spatial light switch device of the present invention forms a spatial light switch step by arranging a plurality of 2-input, 2-output optical switches. Has an equivalent circuit structure of an eight-input modified banyan network in which the parts are stacked in four stages, and expands by combining a plurality of the eight-input modified banyan networks to have an equivalent circuit structure of a 2 ⁿ -input extended modified banyan network. In the spatial light switch device thus configured, NB (I) is the I-th bit of the binary representation of each node in each stage, and FB (J) is the destination node of the 8-input modified Banyan network. The first, third, and fourth spatial light switches are set as the J-th bit in the binary representation, PS is set as 0 for P-polarized light, 1 for S-polarized light, and SC as the polarization control switch state. In the step, SC = PS XOR FB (NB (M) XOR FB (M)) (M = 1, 2, 3 in order of each step) In the second spatial light switch step, SC = PS XOR FB (2 The present invention is characterized in that a polarization switch setting is given as in (11).

Further, the spatial light switch device of the present invention comprises:
When ^{N of} 2 ^{N + 2} inputs is an odd number, first, a 2 ^{N + 2} channel arrangement and a left-right symmetric arrangement are separately formed, and the original channel arrangement, the row and the order within the row are added to the separately formed channel arrangement. By storing and assigning channel numbers of 2 ^{N + 2} or more and then superimposing the two channel arrangements to create an arrangement of 2 ^{N + 3} channels, a plurality of the 8-input modified Banyan networks are combined and expanded. (Claim 1
2).

In the spatial optical switch device of the present invention, when ^N of 2 ^{N + 2} inputs is an even number, first, the same arrangement as that of 2 ^{N + 2} channels is separately formed, and the original channel arrangement is added to the original channel arrangement. The rows of the channel arrangement and the order in the rows are preserved, the channel numbers are assigned 2 ^{N + 2} or more, and then the two channel arrangements are overlapped by shifting in two directions by half the minimum channel interval d, and 2 ^{N + 3} channels In this case, a plurality of the 8-input modified banyan nets are combined and expanded (claim 13).

In order to achieve the above-mentioned object, the spatial light switch device of the present invention provides a polarization control that switches a linear polarization plane to one of two directions orthogonal to each other in two mutually parallel optical axes. Means from said polarization control means.
When light is input along the optical axis of each of the books, light is output in a bypass mode along the corresponding optical axis, and a light beam propagating along one optical axis is in one of the two polarization directions. A light path shifting means for outputting light in an exchange mode in which the light path is shifted by diffraction so as to be propagated along the other optical axis, thereby constituting a two-input two-output optical switch. Claim 14).

Further, the spatial light switch device according to the present invention comprises:
The optical path shifting means comprises a first diffraction grating layer and a second diffraction grating layer which are arranged in parallel at an interval from each other, and each of the diffraction gratings of each layer comprises two plane diffraction gratings having different grating vectors. The beam is shifted by diffracting the first and second diffraction grating layers for S-polarized light, and the first and second diffraction grating layers for P-polarized light. The second diffraction grating layer is also configured to transmit light (claim 15).

Further, space optical switch of the present invention, a light beam the diffraction grating is incident vertically with the only polarized direction required angle by Bragg diffraction, and is configured by inclining the plaid in the thickness direction (according Item 16).

Further, the spatial light switch device of the present invention comprises:
Said diffraction grating is constituted by remembering asymmetry the light beam incident perpendicularly to cause only partial countercurrent required angle by Bragg diffraction, the gratings of the cross-sectional shape (claim 17). Further, the spatial optical switch device of the present invention, the angle of the diffraction grating is polarization direction by Bragg diffraction of light beam incident perpendicularly is set to 48.2 degrees (claim 18).

Further, the spatial light switch device of the present invention comprises:
It is configured such that Δn · D · cos 48.2 ° = π · λ is established between the refractive index modulation Δn of the diffraction grating, the wavelength λ, and the thickness D of the diffraction grating (claim 19). Also,
In the spatial light switch device of the present invention, a holographic diffraction grating is used as each of the diffraction grating layers.

Further, in the spatial light switch device of the present invention, the polarization control means is configured as means for controlling the polarization state by sandwiching the liquid crystal between transparent electrodes and applying a voltage.
Further, the diffraction grating layer is integrally formed on a substrate on which a transparent electrode is formed with the liquid crystal interposed therebetween (claim 21).

Further, the spatial light switch device of the present invention comprises:
In the first diffraction grating layer and the second diffraction grating layer,
Have the same spatial frequency and the same lattice vector direction,
It is configured such that boundaries are eliminated by connecting adjacent diffraction grating regions (claim 22).

Further, in the spatial light switch device of the present invention, in the first diffraction grating layer and the second diffraction grating layer, all the channels are surrounded by boundaries having a predetermined width where no diffraction grating is formed. (Claim 2)
3).

Further, the spatial light switch device according to the present invention comprises:
The first diffraction grating layer is provided integrally on one surface of the transparent flat plate, and the second diffraction grating layer is provided integrally on the other surface of the transparent flat plate.

[0033]

In the above-mentioned spatial light switch device of the present invention (claim 1), the two-input two-output optical switch constituting each spatial light switch step is controlled by its polarization control means in two directions orthogonal to the linear polarization plane. Is switched to one of the states
Further, by the optical path shifting means, the light beam propagating along one optical axis is shifted in one of the two polarization directions.
The optical path is shifted by diffraction so as to propagate along the other optical axis. As a result, the optical path is switched in both the bypass mode and the exchange mode. Such an operation is repeated in each of the spatial optical switch stages to variably connect spatially multiplexed optical signals.

Further, in this case, the polarization control means configured to control the polarization state by sandwiching the liquid crystal between transparent electrodes and applying a voltage can be segmented in accordance with the channel arrangement. Furthermore, each is controlled independently (claim 2).

In the spatial light switch device of the present invention (claim 3), the beam is shifted by diffracting the S-polarized light by the first and second diffraction grating layers. , P-polarized light is transmitted through both the first diffraction grating layer and the second diffraction grating layer, and a beam shift due to the polarization state is performed between adjacent channels.

Further, in the spatial light switch device according to the present invention (claim 4), the beam is shifted by diffracting the s-polarized light by the first diffraction grating layer and the second diffraction grating layer. , P-polarized light are transmitted through both the first diffraction grating layer and the second diffraction grating layer, and these optical signals pass through a plurality of spatial light switch steps without passing through the air layer. Variable connection of spatially multiplexed optical signals is performed.

The spatial light switch device of the present invention (Claim 5)
Then, the incident light is converted into parallel light by the collimating means in the spatial light switch step on the light input side, and the emitted light is condensed by the light condensing means in the spatial light switch step on the light output side.

Further, in the spatial light switch device of the present invention (claim 6), the second spatial light switch step is laminated with the first spatial light switch step rotated by 90 degrees with respect to the first spatial light switch step. Variable connection of four input optical signals is performed.

Further, in the spatial light switch device of the present invention (claim 7), for the 8-channel input, the first spatial light switch stage has channels 0-channel 4, channel 1-channel 5, channel 2 A beam shift is performed between channel 6, channel 3 and channel 7, and in the second spatial optical switch stage and the third spatial optical switch stage, channel 0-channel 2 and channel 1-
A beam shift is performed among channel 3, channel 4-channel 6, channel 5-channel 7, and in the fourth spatial optical switch stage, channel 0-channel 1, channel 2-channel 3, channel 4-channel 5, channel 6
Performing a beam shift between the channels 7;

In the spatial light switch device of the present invention (claim 8), the optical signal is rotated by 45 degrees between the third spatial light switch step and the fourth spatial light switch step. Furthermore, in the spatial light switch device of the present invention (claim 9), when the paths are displayed in the permutation of the channel numbers of the corresponding beam spots of each step, there are 16 exchange paths of the equivalent circuit as follows. (1) 0-2-3-7-5-4-12-14-15-1
1-9-8 (2) 1-3-2-6-4-5-13-15-14-1
0-8-9 (3) 2-0-1-5-7-6-14-12-13-9
-11-10 (4) 3-1-0-4-6-7-15-13-12-8
-10-11 (5) 4-6-7-3-1-0-8-10-11-15
-13-12 (6) 5-7-6-2-0-1-9-11-1-10-14
12-13 (7) 6-4-5-1-3-2-10-8-9-13
15-14 (8) 7-5-4-0-2-3-11-9-8-12-
14-15 (9) 8-10-11-15-13-12-4-6-7
-3-1-0 (10) 9-11-10-14-12-13-5-7-
6-2-0-1 (11) 10-8-9-13-15-14-6-4-5
-1-3-2 (12) 11-9-8-12-14-15-7-5-4
-0-2-3 (13) 12-14-15-11-9-8-0-2-3
-7-5-4 (14) 13-15-14-10-8-9-1-3-2
-6-4-5 (15) 14-12-13-9-11-10-2-0-
1-5-7-6 (16) 15-13-12-8-10-11-3-3-1
0-4-6-7

These paths correspond to the ON / O of the polarization control means.
This is a path where non-blocking cross-connect routing can be performed by FF control. Therefore, it can be understood that, following the exchange path of each channel, the equivalent circuit matches the path of the two-dimensional multilayer switch, and an effective configuration is obtained. Actually, there is a cross-connect route on the 16th floor, but a structure in which a 4-input 4-output non-blocking and cross-connect routing network structure is extended to 16-input 16-output by butterfly connection while maintaining non-blocking. Therefore, non-occlusion is guaranteed.

In the spatial light switch device of the present invention (claim 10), when the paths are displayed in the permutation of the channel numbers of the corresponding beam spots of each step, the exchange paths of the equivalent circuit are as follows. is there. (1) 0-4-6-4-5-13-9-11-9-8 (2) 1-5-7-5-4-12-8-8-10-8-9 (3) 2-6 -4-6-7-15-11-11-9-1-1
0 (4) 3-7-5-7-6-14-10-10-8-10-1
1 (5) 4-0-2-0-1-9-13-15-13-1
2 (6) 5-1-3-1-0-8-12-14-12-1
3 (7) 6-2-0-2--3-11-15-13-15-
14 (8) 7-3-1-3-2-2-10-14-12-14
15 (9) 8-12-14-12-13-5-3-1-3-1
0 (10) 9-13-15-13-12-4-0-2-0
-1 (11) 10-14-12-14-15-7-3-1-
3-2 (12) 11-15-13-15-14-6-2-0-
2-3 (13) 12-8-10-8-9-1-5-7-5-4 (14) 13-9-11-9-8-0-4-6-4-5 (15) 14-10-8-10-11-3-7-5-5-7
-6 (16) 15-11-9-11-10-2-6-4-6
-7

These paths also correspond to the ON / O of the polarization control means.
This is a path where non-blocking cross-connect routing can be performed by FF control. Therefore, it can be understood that, following the exchange path of each channel, the equivalent circuit matches the path of the two-dimensional multilayer switch, and an effective configuration is obtained. In practice, there is a cross-connect route on the 16th floor, but for the same reason as above, non-blocking is guaranteed.

Further, in the spatial light switch device according to the present invention (claim 11), there are a plurality of exchange paths along the exchange path of the equivalent circuit of the eight-input modified banyan network, and these paths are also ON / OFF of the polarization control means. This is a route that allows non-blocking cross-connect routing by control. In the spatial light switch device of the present invention (claim 12),
When ^{N of} 2 ^{N + 2} inputs is an odd number, first, a 2 ^{N + 2} channel arrangement and a left-right symmetric arrangement are separately formed, and the original channel arrangement, the row and the order within the row are added to the separately formed channel arrangement. After storing and assigning a channel number of 2 ^{N + 2} or more, the two channel arrangements are overlapped to form an arrangement of 2 ^{N + 3} channels, thereby extending the combination of the 8-input modified Banyan network.

Furthermore, in the spatial optical switch device of the present invention (claim 13), when ^N of 2 ^{N + 2} inputs is an even number, the same arrangement as that of the 2 ^{N + 2} channels is first made separately, and this is made separately. In the channel arrangement, the rows of the original channel arrangement and the order in the rows are preserved, and channel numbers of 2 ^{N + 2} or more are assigned. Then, the two channel arrangements are shifted in two directions by half the minimum channel interval d to overlap. In addition, by forming an arrangement of 2 ^{N + 3} channels, a plurality of the 8-input modified Banyan networks are combined and expanded.

The spatial light switch device of the present invention (Claim 1)
In 4), the polarization control means switches the linear polarization plane to one of two directions orthogonal to each other, and furthermore, the light path shift means causes the light beam propagating along one optical axis to be in the two directions.
In one state of the two polarization directions, the light path is shifted by diffraction so as to propagate along the other optical axis.
As a result, the optical path is switched in both the bypass mode and the exchange mode.

Further, in the spatial light switch device according to the present invention (claim 15), the first and second diffraction grating layers (each of which is a diffraction grating layer) for S-polarized light.
A holographic diffraction grating can also be used; the beam is shifted by diffracting in claim 20), and P-polarized light is transmitted through both the first diffraction grating layer and the second diffraction grating layer.

[0048] In the optical space switch device of the present invention (Claim 16, 17), by a required angle causes polarization direction by Bragg diffraction light beams the diffraction grating is incident perpendicularly. Then, the angle at which the diffraction grating is polarization direction by Bragg diffraction of light beam incident perpendicularly is set to 48.2 degrees (claim 18). Also, at this time, the refractive index modulation Δn of the diffraction grating,
Δn · D · co between the wavelength λ and the thickness D of the diffraction grating
s48.2 ° = π · λ is established (claim 19).

Further, in the spatial light switch device of the present invention (claim 21), since the diffraction grating layer is integrally formed on the substrate on which the transparent electrode is formed with the liquid crystal constituting the polarization control means interposed therebetween, it is possible to manufacture the device. It will be easier.

Further, in the spatial light switch device according to the present invention (claim 22), the first diffraction grating layer and the second diffraction grating layer have the same spatial frequency and the same diffraction vector in the same direction. Since the lattice areas are connected, it is suitable for inputting many optical signals.

Further, in the spatial light switch device of the present invention (claim 23), in the first diffraction grating layer and the second diffraction grating layer, all the channels have a predetermined width where no diffraction grating is formed. Crosstalk is less likely to occur because of the boundary between

Further, in the spatial light switch device of the present invention (claim 24), the first diffraction grating layer is provided integrally on one surface of the transparent flat plate, and the second diffraction grating layer is provided on the other surface of the transparent flat plate. Since they are provided integrally, positioning during assembly can be performed easily and accurately.

[0053]

Embodiments of the present invention will be described below with reference to the drawings. (A) Description of First Embodiment FIG. 1A is a schematic diagram showing a two-input two-output optical switch as a unit switch of the present spatial optical switch device. A polarization control means 10 for switching the linear polarization plane to one of two orthogonal directions during an optical axis parallel to each other (one is channel A and the other is channel B); Optical path shifting means 20 for shifting the optical path by diffraction so that the light beam propagated along one of the two polarization directions propagates along the other optical axis.

Here, the polarization control means 10 is configured as means for controlling the polarization state by sandwiching the liquid crystal between the transparent electrodes 10A and 10B and applying a voltage. Also,
The optical path shifting means 20 includes a transparent flat plate 21 such as a glass plate.
And a first diffraction grating layer 22 and a second diffraction grating layer 23 which are arranged in parallel at a distance from each other, and the diffraction gratings of the respective layers 22, 23 are formed by two plane diffraction gratings having different grating vectors. For the S-polarized light, the first diffraction grating layer 22 and the second diffraction grating layer 23
The beam is shifted by diffracting the light in the first direction, and the first and second diffraction grating layers 22 and 23 transmit the P-polarized light. In this case, a layer using a holographic diffraction grating is used as each of the diffraction grating layers 22 and 23.

[0055] In this case, the light beam diffraction grating is incident vertically with the only polarized direction required angle by Bragg diffraction, and is configured by inclining the plaid in the thickness direction. Further, as shown in FIG. 2, configured to impart asymmetry in the grating of the cross-sectional shape, a light beam the diffraction grating is incident vertically may be only partial countercurrent required angle by Bragg diffraction.

Further, in this case, the diffraction grating layer 22 is integrally formed on the substrate 11 on which the transparent electrode is formed with the liquid crystal interposed therebetween. This simplifies manufacturing. Further, the first diffraction grating layer 22 may be provided integrally on one surface of the transparent flat plate 21, and the second diffraction grating layer 23 may be provided integrally on the other surface of the transparent flat plate 21. In this way, positioning at the time of assembly can be performed easily and accurately.

In FIGS. 1A and 2, the diffraction grating layers 22 and 23 are drawn to be thicker in order to clarify their existence.
The thickness ratio between the diffraction grating layers 22 and 23 is not as shown in FIGS.

In this way, the two-input two-output optical switch can switch the optical path between the two parallel channels A and B. That is, when linearly polarized light is made incident from the channels A and B, when the light is parallel to the paper surface (P-polarized light) and when the polarization plane is perpendicular to the paper surface (S-polarized light), the light is made to travel straight without exchanging the optical path ( It is possible to perform switching for changing the optical path (bypass mode) or switching (exchange mode).

Then, the polarization state is changed from S to P or P
In order to actively change from
0 is used, and the first and second diffraction grating layers 22 and 23 are used to diffract the light beam according to the polarization state.

Further, in the configuration in which the optical channels parallel to each other and the plane means perpendicular to the optical axis are stacked, it is possible to two-dimensionally structure a plurality of units by using this as a unit. It is also possible to stack a plurality of sets of the structure thus configured in multiple stages in the optical axis direction, which is an advantageous configuration when configuring a multi-channel switch.

The first and second diffraction grating layers 22, 23
As described above, a holographic diffraction grating is used. This diffraction grating uses a plane diffraction grating (plane grating) composed of parallel grating fringes, and transmits light incident perpendicular to the diffraction grating to the other channel. Diffracted toward.

At this time, in order to efficiently perform the Bragg diffraction of the light, the structure is such that the lattice fringes in the cross section are inclined as described above. Further, since the diffraction direction of the light is different between the channels A and B, the inclination direction of the lattice fringe is changed symmetrically in each region. That is, it is symmetrical with respect to the boundary surface of the channel.

Further, since the diffraction grating acts on S-polarized light to diffract light and transmits light without acting on P-polarized light, the holographic diffraction grating is required under special conditions. Has been created. This condition will be described later.

It is to be noted that FIG.
FIG. 1 shows the configuration of FIG. 1A viewed from the light incident direction.
As shown in (b), a simplified symbol in which two black circles are connected by a line will be represented. Black circles represent channels, and line segments indicate that optical paths can be exchanged between channels at both ends.

By the way, the approximate expression of the diffraction efficiency according to the coupled wave theory is expressed as follows for each of the S-polarized light and the P-polarized light. η _S = sin ² [(πΔnD) / (λcos ^1/2 θ)] (1) η _P = sin ² [(πΔnDcos ^1/2 θ) / λ] (2) (1), (2) As can be seen from the equation, both are sin ²
And the periods are different. Here, Δn is the refractive index modulation, D is the thickness of the hologram medium, λ is the wavelength of light, and θ is the diffraction angle (see FIG. 4).

To realize a polarizing beam splitter (PBS) function of diffracting S-polarized light by almost 100% and transmitting almost P-polarized light by a holographic diffraction grating, FIG. Hologram conditions are determined such that the second peak at which the efficiency with respect to S-polarized light is maximized matches the valley at which the efficiency with respect to P-polarized light is minimized, as shown in FIG. .

(ΠΔnD) / (λcos ^1/2 θ) = (3/2) · π (3) (πΔnDcos ^1/2 θ) / λ = π (4) By dividing by equation (3), cos θ = 2 /
3 is obtained, and θ = 48.2 degrees. Furthermore, (3)
A combination of D and Δn is selected so that equation (4) holds. For example, if D = 15 μm, Δn = 0.069
Should be realized.

FIG. 5 is an explanatory view of the beam shift phenomenon when the wavelength of light changes. When a semiconductor laser is used as a light source, the wavelength changes due to temperature, drive current, individual difference, and the like. It needs to be considered.

Now, assuming that an optical path indicated by a solid line is taken at the wavelength λ, when the wavelength is λ + Δλ (Δλ> 0), the diffraction angle increases (from θ to θ ′), and the optical path is indicated by a dotted line. Changes as shown. As a result of diffraction by the two-layer hologram, the beam is translated by Δx, but the propagation direction is not changed.

Then, the beam shift amount Δx is determined as follows: the interval between the two hologram layers tg = 1 mm, θ = 48.2 degrees, n
= 1.6, Δx = 40 nm, Δx = 40
μm. When Δλ <0, the beam shift occurs in the opposite direction (Δx <0). However, the beam shift caused by the wavelength change described above does not pose a problem in practical use by providing a margin for the channel interval.

(B) Description of the Second Embodiment FIG. 6 is a diagram showing a wiring structure of a 4-input / 4-output (4 × 4) cross-connect switch. In FIG. 6, four channels are numbered 0, 1, 2, and 3. The wiring structure has two stages.

That is, in this case, the two-input, two-output optical switches shown in FIG. 1A or FIG. 2 are arranged in parallel so that their incident surfaces are parallel to each other to form a spatial optical switch step portion. Then, the second spatial light switch step NW2 (which may be simply referred to as the second step NW2) is rotated by 90 degrees with respect to the first spatial light switch step NW1 (which may be simply referred to as the first step NW1). The four-input four-output spatial optical switch is formed by laminating the switches in a state where they are placed in the same state.

More specifically, this 4-input 4-output space optical switch can be configured as shown in FIG. That is, as shown in FIG. 7A, the first stage NW1 is configured to be switchable between the channels 0-2 and 1-3, and
In the stage NW2, as shown in FIG.
It is configured to be able to switch between 1 and 3.
Thus, the wiring of FIG. 6 can be realized.

Thus, a four-input four-output spatial optical switch is configured such that the beam shift due to the polarization state can be performed only between the closest channels. Each stage is formed by laminating the elements shown in FIGS. FIGS. 8A to 8F are schematic diagrams viewed from the incident direction of the beam.

First, FIG. 8A shows a polarization control element SW1 for independently controlling the polarization state of a beam propagating through four channels. This is the 2 input 2
As described for the output optical switch, for example, a configuration is used in which the liquid crystal is sandwiched between transparent electrodes and the polarization is rotated by 90 degrees by applying a voltage. A transparent electrode is provided for each channel and controlled independently. That is, the polarization control means is segmented in accordance with the channel arrangement and integrally formed so that each can be controlled independently.

FIG. 8B shows the first diffraction grating layer H1. In this case, the image is divided into four segments, but is actually composed of two types of lattices. This means that there may be no boundaries between the grids for channels 0,1 and channels 2,3. The segments shown by the same figure represent holographic diffraction gratings having the same grating vector.

FIG. 8C shows the second diffraction grating layer H1 '. The second diffraction grating layer H1 'has a structure in which the first diffraction grating layer H1 is rotated around the XX' axis and turned upside down. Also in this case, there may be no boundary between the grids for channels 0 and 1 and channels 2 and 3.

That is, in this case, the first diffraction grating layer H
In the first and second diffraction grating layers H1 ', the boundary is eliminated by connecting adjacent diffraction grating regions having the same spatial frequency and the same grating vector direction.

8A to 8C (the polarization control element SW1, the first diffraction grating layer H1 and the second diffraction grating layer H1 ') are stacked to form the first stage NW1. Structure.

Next, the second stage NW2 is shown in FIG.
The element shown in FIG. That is, FIG.
FIG. 8D shows a polarization control element S similar to that shown in FIG.
W2. 8E and 8F are the same diffraction grating layers as FIGS. 8B and 8C, respectively, but the first diffraction grating layer H2 in FIG. FIG. 8B
Is arranged such that the first diffraction grating layer H1 is rotated by 90 degrees in the plane. Further, the second diffraction grating layer H2 'in FIG.
The (c) second diffraction grating layer H1 'is arranged to be rotated by 90 degrees on the inner surface.

A stack of the above-mentioned components (polarization control element SW2, first diffraction grating layer H2 and second diffraction grating layer H2 ') shown in FIGS. 8 (d) to 8 (f) corresponds to the second stage NW2. Structure.

Therefore, from the above, the first diffraction grating layer H1
It can be seen that (H2) and the second diffraction grating layer H1 ′ (H2 ′) are configured to two-dimensionally arrange two pairs of two plane diffraction grating segment pairs having different grating vectors. .

FIG. 9 is a schematic view showing the above 4 × 4 optical switch formed by laminating two step structures. In this case, the first spatial light switch step portion NW1 and the second A microlens array (collimating means) 31 for collimating the light emitted from the four optical fibers LF is provided on the input side of the four-input four-output spatial optical switch including the spatial optical switch step NW2, and a four-input four-output space is provided. A microlens array (light condensing means) 32 for converging and entering the four optical fibers LF on the output side of the optical switch
Is provided. In FIG. 9, G1 and G2
Is a transparent flat plate.

As described above, this four-input four-output spatial optical switch is composed of a polarization control means, a first diffraction grating layer, and a second diffraction grating layer which are integrally laminated without interposing an air layer. And the spatial light switch stepped part is 2
First, it is configured to be integrally laminated without interposing an air layer.

As described above, the means for switching the linear polarization plane to one of two directions orthogonal to each other and the structure for shifting the optical path by controlling the polarization state by two diffraction grating layers are the same. Are two-dimensionally combined to form a stepped structure, and by stacking a plurality of stepped structures that shift the optical path in different directions, a two-dimensional channel arrangement is achieved by only shifting the optical path between adjacent channels.
A multi-stage optical cross-connect switch can be realized,
Further, since the optical path changing portion of the spatial light switch has a laminated structure of a polarization control element and a diffraction grating, it is simple and has a configuration suitable for channels arranged two-dimensionally. , Has a plurality of segments, but there are many things that are common only with different orientations and front and back, and the types of parts to be manufactured are advantageous in that they are not as many as the number of diffraction grating layers, Since the optical path polarization in each stage is performed between adjacent channels, the optical path length can be minimized and the channel interval can be reduced.

As a method of laminating each planar element, for example, a method in which first and second diffraction grating layers are formed on both surfaces of a transparent glass plate and a liquid crystal polarization controlling element are alternately bonded. However, other means may be used.

(C) Description of the Third Embodiment FIG. 10 is a diagram showing a wiring structure of an 8-input / 8-output (8 × 8) cross-connect switch. In this FIG.
The eight channels are numbered 0-7. And
The wiring structure has four stages.

That is, in this case, the first spatial light switch step (first stage) NW1 to the fourth spatial light switch step (fourth stage) NW4 have the configuration shown in FIG. 1A or FIG. The four-input two-output optical switches are arranged in parallel, and more specifically, as shown in FIG.
On the optical input surface, when the first adjacent channel interval is d and the coordinates of the origin O are (0, 0), channel 0 is (0, d), channel 1 is (d, d), and channel 2 is ( d, 2d), channel 3 to (2d, 2d), channel 4 to (d, 0), channel 5 to (2d, 0), channel 6 to (2d, d), and channel 7 to (3d, d). As shown in FIG. 11A, the first spatial optical switch stage (first stage) NW1 has channels 0-channel 4, channel 1-channel 5, channel 2-channel 6, and channel 3- A beam shift structure between channels 7 is provided, and FIG.
As shown in FIGS. 1 (b) and 1 (c), the second spatial optical switch stage (second stage) NW2 and the third spatial optical switch stage (third stage) NW3 have channel 0-channel 2 respectively. , Channel 1-channel 3, channel 4-channel 6, and channel 5-channel 7 are provided, and as shown in FIG. 11 (d), a fourth spatial light switch stage (fourth stage) NW4 Then, a beam shift structure is provided between channel 0-channel 1, channel 2-channel 3, channel 4-channel 5, channel 6-channel 7, and
This constitutes a banyan net-type space optical switch having eight inputs and eight outputs.

Thus, an eight-input eight-output spatial optical switch is configured so that the beam shift due to the polarization state can be performed only between the nearest channel and the second adjacent channel.

From the above, the second stage NW2 and the third stage NW
3 shows the same wiring structure, but this is to generate a detour to prevent blocking.
Each stage is formed by stacking the elements shown in FIGS. All are schematic diagrams viewed from the incident direction of the beam.

First, FIG. 12A shows a polarization control element SW1 for independently controlling the polarization state of a beam propagating through four channels. In this case, the number of segments is 8, but the structure is the same as that described for the 4 × 4 switch. In other words, the polarization control means is segmented in accordance with the channel arrangement and integrally formed so that each can be controlled independently.

FIG. 12B shows a first diffraction grating layer H1, which is divided into eight segments in this case, but is composed of two types of gratings. Also, there may be no boundary line between the grids for channels 0, 1, 2, 3 and for channels 4, 5, 6, 7. Also in this case, the segments shown by the same figure represent holographic diffraction gratings having the same lattice vector.

FIG. 12C shows the second diffraction grating layer H1 '. And also in this case, channels 0,
There may be no boundaries between the grids for 1,2,3 and the channels 4,5,6,7.

That is, in the first diffraction grating layer H1 and the second diffraction grating layer H1 ', boundaries are eliminated by connecting adjacent diffraction grating regions having the same spatial frequency and the same direction of the grating vector. It will be comprised in.

12A to 12C (the polarization control element SW1, the first diffraction grating layer H1 and the second diffraction grating layer H1 ') are stacked in the first stage NW1.
The structure is as follows.

Next, the second stage NW2 is formed by laminating the elements SW2, H2 and H2 'shown in FIGS. 12 (a), 12 (d) and 12 (e). In the third stage NW3, the elements SW3, H3, and H3 'shown in FIGS. 12A, 12F, and 12G are stacked.

In this case, FIGS. 12D and 12F and FIG.
(E) and (g) are the same diffraction grating layer, and have a structure in which FIGS. 12 (c) and 12 (b) are rotated around YY 'and turned upside down. In addition, between the third stage NW3 and the fourth stage NW4, 1/45 for rotating the polarization plane by 45 degrees is used.
A two-wave plate is sandwiched.

Further, the fourth stage NW4 is formed by stacking the elements SW4, H4, H4 'shown in FIGS. 12 (a), (h) and (i). FIG. 12 (i) shows FIG.
The structure is turned around Y 'and turned upside down.

As described above, there are eight holographic diffraction grating layers as shown in FIGS. 12 (b) to (i), and there are three patterns as shown in FIGS. 12 (b), (c) and (h). is there.
Therefore, from the above, the first diffraction grating layer H1 (H2 to H4)
The second diffraction grating layer H1 '(H2' to H4 ') is configured so that two sets of two plane diffraction grating segment pairs each having a different grating vector are arranged two-dimensionally.

FIG. 13 is a configuration diagram of an 8 × 8 optical switch formed by laminating the above-described four-stage structure, viewed from a direction perpendicular to the channel. First diffraction grating layers H1 to H1 of each stage
H4, the second diffraction grating layers H1 'to H4' are represented by being formed on both sides of a common transparent flat plate G1 to G4 (see a thick line).

Also in this case, the first spatial light switch step NW1 to the fourth spatial light switch step NW4 are also used.
A microlens array (collimating means) 31 for collimating the light emitted from the eight optical fibers LF is provided on the input side of the 8-input 8-output spatial optical switch composed of , A microlens array (light collecting means) 32 for converging and entering the eight optical fibers LF.
In addition, 40 in FIG. 13 is a 1/2 wavelength plate.

The dimensions of the laminated structure shown in FIG. 13 are, for example, when the channel spacing is 1.8 mm, the input surface is 7.2 ×
5.4 mm, the length in the thickness direction can be about 18 mm. However, it is the dimension of only the effective portion of the optical path polarization switch section, and does not include the dimensions of the wiring for driving the polarization control element and the coupling section with the optical fiber.

As described above, this eight-input eight-output spatial optical switch is composed of a polarization control means, a first diffraction grating layer, and a second diffraction grating layer which are integrally laminated without interposing an air layer. And the space optical switch step is 4
First, it is configured to be integrally laminated without interposing an air layer.

As described above, the means for switching the linear polarization plane to one of two directions orthogonal to each other and the structure for shifting the optical path by controlling the polarization state by the two diffraction grating layers are the same. Are two-dimensionally combined to form a stepped structure, and furthermore, by stacking a plurality of stepped structures for shifting the optical path in different directions and a wave plate, a multi-stage optical arrangement of a two-dimensional channel arrangement only by shifting the optical path between adjacent channels. A cross-connect switch can be realized, and the optical path changing unit of the spatial light switch is simple because it has a laminated structure of a polarization control element and a diffraction grating.
The structure is suitable for channels arranged two-dimensionally, and the diffraction grating layer constituting each stage has a plurality of segments, but many are common only with different orientations and front and back. Is advantageous in that the number of components is not as large as the number of diffraction grating layers, and the optical path polarization in each stage is performed between adjacent channels, so that the optical path length is shortest and the channel spacing is reduced. It is also possible.

(D) Description of the Fourth Embodiment The fourth embodiment relates to a spatial light switch device having an equivalent circuit structure of an eleven-stage cross-banyan network as shown in FIG. The two-input two-output optical switch as a unit switch of this spatial optical switch device is the same as that described with reference to FIG.

The spatial light switch device having the equivalent circuit structure of the eleven-stage cross-banyan network according to this embodiment includes the means 10 for switching the linearly polarized beam to one of two orthogonal directions, as described above. Diffraction grating layers 2
By controlling the polarization state according to 2, 23,
Using a structure that shifts the optical path as a unit, two-dimensionally combining the same structures to form a stepped structure, and further, stacking a plurality of stepped structures that shift the optical path in different directions and a wave plate into thin films. However, by doing so, it is possible to minimize the beam length and the optical path length difference of each beam, and only by shifting the optical path difference between adjacent channels, a multi-stage optical cross-connect in a two-dimensional channel arrangement. The switch can be realized.

That is, in the two-input two-output optical switch as shown in FIGS. 1A and 2 described above, the two-input two-output light switch is set so that the surfaces formed by two mutually parallel optical axes are parallel to each other. By arranging a plurality of switches, a spatial light switch step is formed.
By stacking one stage, a spatial optical switch device having an equivalent circuit structure of an 11-stage cross-banyan network is configured.

Then, the 16 inputs, 16 outputs 1 shown in FIG.
In order to realize this wiring structure equivalent to the wiring structure of the one-stage cross-connect switch with the two-input two-output optical switch having the above-described basic configuration, an appropriate hologram array for beam polarization is laminated for each stage. Is necessary, and 1
The configuration is such that the six input beams are arranged two-dimensionally and matched with the multi-channel multi-stage switching operation by the hologram array.

When 16 input beams are arranged two-dimensionally as shown in FIG. 16, that is, on the optical input surface, d is an adjacent channel interval, and channel 0 (CH0) is the origin (0, 0).
Further, channel 1 (CH1) is set to (0, -2d),
Channel 2 (CH2) is assigned to (2d, 0) and channel 3 (C
H3) is (2d, -2d), channel 4 (CH4) is (d, -d), and channel 5 (CH5) is (d, -3).
d), channel 6 (CH6) is (3d, -d), channel 7 (CH7) is (3d, -3d), and channel 8 (CH
8) at (d, 0) and channel 9 (CH9) at (d, -2).
d), channel 10 (CH10) is (3d, 0), channel 11 (CH11) is (3d, -2d), channel 1
2 (CH12) to (0, -d) and channel 13 (CH1
3) is (0, -3d), channel 14 (CH14) is (2d, -d), and channel 15 (CH15) is (2d,
-3d), as shown in FIG.
The first, fourth, seventh and tenth spatial light switch steps (1 step, 4
Channels 0-2, 4-6, 1)
-3,5-7,8-10,12-14,9-11,13
-15 can be switched between the second, fifth, eighth and eleventh
In the spatial light switch stages (2 stages, 5 stages, 8 stages, and 11 stages), channels 0-1, 4-5, 2-3, 6-7 and 12-
13, 8-9, 14-15, and 10-11 so as to be switchable, and the third and ninth spatial light switch steps (3 steps, 9 steps)
Stage), channels 0-4, 1-5, 2-6, 3-7,
8-12, 9-13, 10-14, and 11-15 so as to be switchable, and in the sixth spatial optical switch stage (six stages), channels 0-8, 12-4, 1- 9,1
3-5, 2-10, 14-6, 3-11, and 15-7 can be switched.

Thus, the equivalent circuit shown in FIG. 15 is obtained.
Furthermore, in the optical communication path structure that can realize this equivalent circuit by combining the basic configuration of the thin-film multi-stage spatial optical switch, there is a non-blocking cross-connect routing algorithm when the S-polarized light is incident, and can be described as follows. .

NB (I) is represented by 1 in binary notation of each node at each stage.
FB (J) is the J-th bit in the binary representation of the destination node, PS is 0 for P-polarized light, 1 for S-polarized light, and SC for polarization control. Assuming the switch state (0 = OFF, 1 = ON), SC = PS XOR (NB (3) XOR FB (3)) at the first, fourth, seventh, and tenth stages, two, five, and eight stages , At stage 11, SC = PS XOR (NB (4) XOR FB (4)) 3rd stage, at stage 9 SC = PS XOR (NB (2) XOR FB (2)) At stage 6, SC = PS XOR The polarization switch setting is given as (NB (1) XOR FB (1)).

Note that X XOR Y means that X and Y are exclusive ORed.

When the two-dimensional arrangement of each channel of the input beam is determined as described above, the path is displayed in the permutation of the channel number of the corresponding beam spot on each layer. Are the following 16 types. (1) 0-2-3-7-5-4-12-14-15-1
1-9-8 (2) 1-3-2-6-4-5-13-15-14-1
0-8-9 (3) 2-0-1-5-7-6-14-12-13-9
-11-10 (4) 3-1-0-4-6-7-15-13-12-8
-10-11 (5) 4-6-7-3-1-0-8-10-11-15
-13-12 (6) 5-7-6-2-0-1-9-11-1-10-14
12-13 (7) 6-4-5-1-3-2-10-8-9-13
15-14 (8) 7-5-4-0-2-3-11-9-8-12-
14-15 (9) 8-10-11-15-13-12-4-6-7
-3-1-0 (10) 9-11-10-14-12-13-5-7-
6-2-0-1 (11) 10-8-9-13-15-14-6-4-5
-1-3-2 (12) 11-9-8-12-14-15-7-5-4
-0-2-3 (13) 12-14-15-11-9-8-0-2-3
-7-5-4 (14) 13-15-14-10-8-9-1-3-2
-6-4-5 (15) 14-12-13-9-11-10-2-0-
1-5-7-6 (16) 15-13-12-8-10-11-3-3-1
0-4-6-7

These paths are paths that can be realized by the equivalent circuit of FIG. 15, and also integrally correspond to the channel connection constituted by the hologram array of FIG.
This is a path that allows non-blocking cross-connect routing by ON / OFF control of the polarization control element.

Therefore, it is understood that, when the exchange path of each channel is followed, the equivalent circuit and the path of the two-dimensional multilayer switch coincide with each other, resulting in an effective configuration.

In this case, there are actually 16 floors of cross-connect routes, but a 4-input 4-output non-blocking and cross-connect routing network structure is provided by butterfly connection while maintaining non-blocking. Since the structure is expanded to 16 inputs and 16 outputs, non-blocking is guaranteed.

As described above, by combining the deflection control element and the hologram diffraction element, a small-sized multi-input multi-output spatial light switch having a thin-film laminated structure is formed, thereby enabling a two-dimensional array of 16 beams. 16
It is possible to optically realize the non-blocking cross-connect routing of the 11-stage cross-banyan network.

(E) Description of Fifth Embodiment Next, a fifth embodiment will be described. The fifth embodiment has a spatial light structure having an equivalent circuit of a nine-stage expanded modified Banyan network as shown in FIG. 18 (this equivalent circuit is equivalent to a wiring structure of a nine-stage 16-input / 16-output cross-connect switch). In the case of the switch device, in this case, the surface formed by two mutually parallel optical axes in the two-input two-output optical switch (basic switch) as shown in FIGS. By arranging a plurality of two-input and two-output optical switches so as to be parallel to each other, a spatial optical switch step is formed, and nine spatial optical switch steps are laminated to form a nine-stage expanded deformed banyan net. This constitutes a spatial light switch device having the equivalent circuit structure described above.

In this case, the above wiring structure is
(A) In order to realize the basic configuration shown in FIG. 2, the hologram array for each stage is arranged such that when 16 input beams are arranged two-dimensionally as shown in FIG.
Is the adjacent channel interval, channel 0 (CH0) is the origin (0, 0), and channel 1 (CH0) is (d,
-D), channel 2 (CH2) is (0, -2d), channel 3 (CH3) is (d, -3d), and channel 4 (CH
4) at (2d, 0) and channel 5 (CH5) at (3d, 0).
-D), channel 6 (CH6) is (2d, -2d), channel 7 (CH7) is (3d, -3d), channel 8
(CH8) is (d, 0), channel 9 (CH9) is (0, -d), and channel 10 (CH10) is (d, -2).
d), channel 11 (CH11) is (0, -3d), channel 12 (CH12) is (3d, 0), channel 13
(CH13) is changed to (2d, -d) and channel 14 (CH1
4) is arranged at the position of (3d, -2d) and the channel 15 (CH15) is arranged at the position of (2d, -3d). In the first and sixth spatial optical switch steps (1st and 6th steps), the channels 0- 4,1-
5,2-6,3-7,8-12,9-13,10-1
Switchable between 4, 11 and 15
7, 8 spatial optical switch steps (2 steps, 3 steps, 7 steps, 8 steps)
Stage), channels 0-2, 1-3, 4-6, 5-7,
9-11, 8-10, 13-15, and 12-14. The fourth and ninth spatial light switch steps (4
Channels, 9 stages), channels 0-1, 2-3, 4-5, 6
-7, 8-9, 10-11, 12-13, and 14-15 so as to be switchable. In the fifth spatial light switch stage (five stages), channels 0-8, 1-9, 2 -10,3
It can be switched between -11, 4-12, 5-13, 6-14 and 7-15.

In this way, the equivalent circuit shown in FIG. 18 can be obtained. However, in an optical communication path structure in which this equivalent circuit can be realized by a combination of the basic configuration of the above-mentioned thin-film multi-stage spatial optical switch, if the S-polarized light incidence is assumed, An occlusion cross-connect routing algorithm exists and is described as follows:

NB (I) is expressed by the binary notation I of each node at each stage.
FB (J) is the J-th bit in the binary representation of the destination node, PS is 0 for P-polarized light, 1 for S-polarized light, and SC for polarization control. Assuming the switch state (0 = OFF, 1 = ON), SC = PS XOR (NB (M) XOR FB (M)) at the first, third, fourth, sixth, eighth, and ninth stages (each stage) M = 2,3,4,2,3,4) SC = PS XOR (NB (3) XOR FB (3)) at 2nd and 7th stages SC = PS XOR (NB (1) XOR at 5th stage FB (1)) polarization switch settings are provided.

Note that also in this case, X XOR Y is X
And Y are exclusive-ORed.

When the two-dimensional arrangement of each channel of the input beam is determined as described above, the path is displayed in the permutation of the channel number of the corresponding beam spot on each layer. Are the following 16 types. (1) 0-4-6-4-5-13-9-11-9-8 (2) 1-5-7-5-4-12-8-10-8-9 (3) 2-6 -4-6-7-15-11-11-9-1-1
0 (4) 3-7-5-7-6-14-10-10-8-10-1
1 (5) 4-0-2-0-1-9-13-15-13-1
2 (6) 5-1-3-1-0-8-12-14-12-1
3 (7) 6-2-0-2--3-11-15-13-15-
14 (8) 7-3-1-3-2-2-10-14-12-14
15 (9) 8-12-14-12-13-5-3-1-3-1
0 (10) 9-13-15-13-12-4-0-2-0
-1 (11) 10-14-12-14-15-7-3-1-
3-2 (12) 11-15-13-15-14-6-2-0-
2-3 (13) 12-8-10-8-9-1-5-7-5-4 (14) 13-9-11-9-8-0-4-6-4-5 (15) 14-10-8-10-11-3-7-5-5-7
-6 (16) 15-11-9-11-10-2-6-4-6
-7

These paths are paths that can be realized by the equivalent circuit of FIG. 18, and correspond to the channel connection constituted by the hologram array of FIG. This is a route that allows non-blocking cross-connect routing by OFF control.

Therefore, also in this case, it can be understood that, following the exchange path of each channel, the equivalent circuit and the path of the two-dimensional multilayer switch coincide with each other, resulting in an effective configuration. And, in this case, too,
Although there is a cross-connect route on the 16th floor, non-blocking is guaranteed for the same reason as described above.

The holographic banyan spatial light switch is implemented with a nine-stage laminated structure as shown in FIG. Here, the deflection control element SWi of each stage NWi
Are formed so as to be surrounded by a two-dimensional transparent electrode, and the first diffraction grating layer Hi and the second diffraction grating layer
Are formed alternately and the above-mentioned liquid crystal deflection control element SWi is adhered alternately to form a laminated structure. In addition, a 所 要 wavelength plate Wj is interposed at a required portion between the steps. The incident light and the outgoing light are transmitted by an optical fiber array FA, and are configured to use microlens arrays 31 and 32 at both ends in order to form collimated light. Further, FIG. 21 shows a nine-layer stacked three-dimensional structure.

Even in this case, a two-dimensional array of 16 beams is possible, and non-blocking cross-connect routing of a 16-input, 9-stage extended deformed Banyan net can be optically realized by deflection control.

(F) Description of Sixth Embodiment Next, a sixth embodiment will be described. The sixth embodiment relates to a spatial optical switch device having an equivalent circuit structure of a 2 ⁿ (n is an integer of 4 or more) input extended modified Banyan network.

By the way, the basic principle of the present invention can be applied to the construction of a multi-stage connection network provided that the circuit is composed of a combination of two-input, two-output switches. In particular, an 8-input modified banyan network type thin film multi-stage spatial optical switch is used as a basic component module, and as shown in FIG. FIG. 2 shows a configuration that can be extended and configured in this way.
3 is a 2 ⁿ -input extended modified Banyan network.

In FIG. 23, reference numeral 100 denotes a set of 16 inputs 9 shown in FIG.
This is a circuit equivalent to the extended modified Banyan network of stages, and 200 is a circuit in which four 16-input 9-stage extended modified Banyan networks 100 are assembled.

In this case, the non-blocking cross-connect routing is enabled in the case of 2 ⁿ by sequentially expanding based on the polarization control algorithm of the 8-input modified Banyan network.

That is, the polarization control algorithm of the 8-input modified Banyan net is as follows. First, NB (I)
Is the I-th bit in binary notation of each node in each stage, FB (J) is the J-th bit in binary notation of the destination node, and PS is the polarization of the beam incident on a certain node. , And 1 for S-polarized light, and SC as a polarization control switch state (0 = OFF, 1 = ON). In one, three, and four stages, SC = PS XOR (NB (M) XOR FB (M) (M = 1, 2, 3 in the order of each step) In the two steps, a polarization switch setting is given as SC = PS XOR FB (2).

In this case, X XOR Y is equal to X
And Y are exclusive-ORed.

As shown in FIG. 24, the two-dimensional arrangement of 16, 32, and 64 inputs is sequentially changed from the two-dimensional arrangement of eight inputs.
There is an extension scheme, which is expressed as: First, 2
^{When N of N + 2} inputs is an odd number, (1) Create an arrangement of 2 ^{N + 2} channels and a symmetric arrangement separately. (2) Assign the channel number of 2 ^{N + 2} or more to the separately created channel arrangement while preserving the original channel arrangement and the line and the order within the line. (3) Overlay two channel arrangements to create an arrangement of 2 ^{N + 3} channels.

When ^N of 2 ^{N + 2} inputs is an even number, the same arrangement as that of (1) 2 ^{N + 2} channels is made separately. (2) A channel number of 2 ^{N + 2} or more is added to a separately created channel arrangement while preserving the original channel arrangement row and the order within the row. (3) The two channel arrangements are shifted by half the minimum channel interval d in two directions and overlapped to create an arrangement of 2 ^{N + 3} channels.

That is, in the sixth embodiment, FIG.
In the multi-input multi-output spatial optical switch configured based on the basic switch shown in (a) or the like, the 8-input modified banyan network realized by the combination is realized by sequentially expanding the basic configuration modules by butterfly connection. an optical space switch device having an equivalent circuit of the 2 ⁿ input expansion deformation banyan network, further, on the basis of the polarization control algorithm to achieve a non-blocking cross connect routing of 8 input variations banyan network, the 2 ⁿ input expansion deformation Banyan network ,
A spatial optical switch device having a polarization control algorithm that can be sequentially extended and applied, and furthermore, a 2 ^{n + 2} beam incident on an optical communication structure that can be realized in accordance with the equivalent circuit of the above 2 ⁿ input extended modified Banyan network. It can be said that this relates to expansion of the two-dimensional arrangement.

As described above, the spatial optical switch having the expandability of the two-dimensional arrangement according to the third embodiment has an optical communication path represented by an equivalent circuit of a 2 ^{N + 2} input extended modified Banyan network, It has a deflection control algorithm that enables closed cross-connect routing.

In this way, the non-blocking cross-connect routing of the 2 ^{N + 2} input extended modified Banyan network can be realized optically. (G) Others The size of the segment may be designed in consideration of a beam shift or a margin due to a beam diameter or a wavelength variation, and therefore, the size of the segment may be adjusted. For this reason, FIG. 8 (second embodiment) and FIG.
In the second embodiment (third embodiment), the region where the diffraction grating is present is illustrated as being in contact with each other. However, considering the point that it is desired to make the structure as small as possible, as shown in FIG. Is provided at the boundary of the first diffraction grating layer Hi (i
Is a natural number) and in the second diffraction grating layer Hi ′, all channels are surrounded by a boundary having a predetermined width where no diffraction grating is formed, thereby reducing crosstalk. Is also good.

[0139]

As described above in detail, according to the spatial optical switch device of the present invention, a two-input two-output optical switch having a bypass mode and an exchange mode is provided. The two inputs 2 so that the surfaces formed by the optical axes parallel to each other are parallel to each other.
By arranging a plurality of output optical switches, a spatial optical switch step is formed, and a required number of spatial optical switch steps are stacked to form a multi-input multi-output spatial optical switch, and in particular, an optical path of the spatial optical switch. Since the change unit can be a laminated structure of a polarization control element and a diffraction grating, it is simple and can have a configuration suitable for channels arranged two-dimensionally.

The diffraction grating layer constituting each step has a plurality of segments, but many of them are common only with different orientations and front and back sides. It is also advantageous in that there are not as many layers.

Further, since the optical path in each stage is changed between adjacent channels, the optical path length can be minimized, and the channel interval can be reduced. In addition, the method of mounting the diffraction grating layer can be devised to facilitate positioning for manufacturing or mounting. Further, the combination of the polarizing system <br/> control element and the hologram diffraction element,
A small multi-input multi-output spatial optical switch device with a thin-film laminated structure can be easily configured to reduce insertion loss and crosstalk, and to provide non-banyan networks (including extended deformed banyan networks) for non-blocking cross-connect routing. The effect that can be realized is obtained.

[Brief description of the drawings]

FIGS. 1A and 1B show a two-input two-output optical switch according to a first embodiment of the present invention, in which FIG. 1A is a schematic diagram showing the configuration, and FIG. FIG.

FIG. 2 is a schematic diagram showing a configuration of a modified example of the two-input two-output optical switch as the first embodiment of the present invention.

FIG. 3 is a diagram showing efficiency characteristics of a holographic diffraction grating.

FIG. 4 is a sectional view of a holographic diffraction grating.

FIG. 5 is a diagram illustrating a beam shift accompanying a wavelength change.

FIG. 6 is a diagram illustrating inter-channel wiring of a four-input four-output spatial optical switch device according to a second embodiment of the present invention.

FIG. 7 is a wiring structure diagram of each stage of a four-input four-output spatial optical switch device as a second embodiment of the present invention.

FIG. 8 is a schematic diagram showing constituent elements of each stage of a four-input four-output spatial optical switch device as a second embodiment of the present invention.

FIG. 9 is a schematic diagram showing a laminated structure of a four-input four-output spatial optical switch device as a second embodiment of the present invention.

FIG. 10 is a diagram for explaining wiring between channels of an 8-input / 8-output spatial optical switch device according to a third embodiment of the present invention.

FIG. 11 is a wiring structure diagram of each stage of an 8-input / 8-output spatial optical switch device as a third embodiment of the present invention.

FIG. 12 is a schematic diagram showing constituent elements at each stage of an 8-input / 8-output spatial optical switch device as a third embodiment of the present invention.

FIG. 13 is a schematic view showing a laminated structure of an 8-input / 8-output spatial optical switch device as a third embodiment of the present invention.

FIG. 14 is a schematic view showing another example of the holographic diffraction grating layer.

FIG. 15 shows an 11-stage cross according to a fourth embodiment of the present invention.
It is an equivalent circuit diagram of a Banyan network.

FIG. 16 shows an 11 × 16 × 1 according to a fourth embodiment of the present invention.
It is a figure explaining the two-dimensional arrangement of the input beam of a 6 cross connect switch.

FIG. 17 shows an 11 × 16 × 1 according to a fourth embodiment of the present invention.
It is a figure explaining the parallel speech path array of each stage which comprises 6 cross connect switches.

FIG. 18 is an equivalent circuit diagram of a nine-stage extended modified Banyan network according to a fifth embodiment of the present invention.

FIG. 19 shows a 9 × 16 × 16 according to a fifth embodiment of the present invention.
FIG. 3 is a diagram illustrating a two-dimensional arrangement of input beams of a cross-connect switch.

FIG. 20 shows a 9 × 16 × 16 according to a fifth embodiment of the present invention.
It is a figure explaining the parallel speech path array of each stage which constitutes a cross connect switch.

FIG. 21 is a schematic diagram showing a three-dimensional structure of a nine-stage deformed banyan net according to a fifth embodiment of the present invention.

FIG. 22 is a schematic view showing an example of a laminated structure according to a fifth embodiment of the present invention.

FIG. 23 is a block diagram showing an example of an equivalent circuit of a 2 ⁿ -stage extended Banyan network according to a sixth embodiment of the present invention.

FIG. 24 is a diagram for explaining an extension method of a two-dimensional arrangement configuration when 2 ^{N + 2} inputs are performed according to the sixth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Polarization control means 10A, 10B Transparent electrode 11 Substrate 20 Optical path shift means 21 Transparent flat plate 22 First diffraction grating layer 23 Second diffraction grating layer 31, 32 Micro lens array 40 1/2 wavelength plate 100 16 input 9 steps Circuit equivalent to extended deformed banyan network 200 A circuit in which four 16-input 9-stage extended deformed banyan networks are collected Gi Transparent flat plate (transparent glass plate) Hi, Hi 'Diffraction grating layer LA Optical fiber array LF Optical fiber NWi Space optical switch Step Swi Polarization control element Wj 1/2 wavelength plate

Continuation of the front page (56) References JP-A-3-63631 (JP, A) JP-A-3-33725 (JP, A) JP-A-2-308229 (JP, A) Takeshi Yamamoto, et. al. , C-392 Study on miniaturization of polarization control type spatial optical switch, Proceedings of the 1991 IEICE Spring National Convention, Part 4, pp. 146-64. 4-409 Takeshi Yamamoto, et. al. , C-435 Study of banyan network type optical switch by polarization control, Proc. Of the 1990 IEICE Spring Conference, Part 3, pp. 1-95. 3-13 RAYMOND K. , Et. a l. , Polarization components of substrate-mode holographic interconnects, A PPLIED OPTICS, Vol. 26 (Septmber 1990) pp. 3848-3854 J.P. BARRY MCMANUS, et. al. , Switched hol programs for reconfigurable gurable optical interconnection: demonstration of a prototype type device, APP LIED OPTICS, Vol. 27, No. 20 (October 1988) p.p. 4244-4250 (58) Field surveyed (Int. Cl. ⁷ , DB name) G02F 1/31 H04B 10/02 JICST file (JOIS)

Claims (24)

(57) [Claims] During 1. A two mutually parallel optical axes, and the polarization control hand stage switching to either state of the two directions perpendicular linear polarization plane, the polarization control hand stage or al of the two optical When the light along the axes is input, the light is output in the bypass mode along the corresponding optical axis, and the luminous flux propagating along one optical axis is in one of the two polarization directions.
Equipped with two inputs and two output optical switch having an optical path shift means to output the light in extensin-change mode to the optical path shift by the diffraction to propagate along the other optical axes, two of the 2 input 2 output optical switch of so that the surface to create a mutually parallel optical axes to be parallel, respectively, by arranging a plurality said two inputs and two output optical switch, to form a spatial light switch stage unit, the required number of spatial light switch stage unit Characterized by being stacked and stacked to form a multi-input multi-output space optical switch,
Spatial light switch device. 2. A polarization control hand stage, see clamping <br/> the liquid crystal at the transparent electrodes, are configured as a means of controlling the polarization state by applying a voltage, and, channel arrangement the polarization control hand stage 2. The spatial light switch device according to claim 1, wherein the space optical switch device is integrally formed so as to be segmented in accordance with the length of the light source and controlled independently of each other. 3.該光Ro shift hands stage provided with a first diffraction grating layer contact and the second diffraction grating layer arranged in parallel at intervals from each other, with grating vector diffraction grating is different for each layer consists of two plane diffraction grating, S with respect to the polarization shifts the beam by diffracting the second diffraction grating layer and contact the first diffraction grating layer above, for the P-polarized light, the first in first ones where the structure also transmits the diffraction grating layer contact and the second diffraction grating layer, different from the first diffraction grating layer contact and the second diffraction grating layer described above, respectively it <br/> of A multi-input multi-output spatial optical switch configured to two-dimensionally arrange a plurality of pairs of two planar diffraction grating segment pairs having a lattice vector, and to perform a beam shift according to the polarization state between adjacent channels. Make up The spatial light switch device according to claim 1, wherein: 4.該光Ro shift hands stage provided with a first diffraction grating layer contact and the second diffraction grating layer arranged in parallel at intervals from each other, with grating vector diffraction grating is different for each layer consists of two plane diffraction grating, S with respect to the polarization shifts the beam by diffracting the second diffraction grating layer and contact the first diffraction grating layer above, for the P-polarized light, the in the first one where the structure is also to transmit the diffraction grating layer contact and the second diffraction grating layer, said polarization control hand stage, the first diffraction grating layer, the second diffraction grating layer through the air layer configure the optical space switch step portion is integrally laminated without, and, to a spatial light switch stage unit more, integrally laminated without passing through the air layer, constitute a multi-input multi-output optical space switch 2. The spatial light switch according to claim 1, wherein: Location. 5. A spatial optical switch step of the light input side, along with a collimating means to convert the incident light into parallel light are provided, the optical space switch stage of the light output side, focusing for focusing the emitted light wherein the light hand stage is al provided, the spatial optical switch apparatus according to claim 1. 6. A in two mutually parallel optical axes, and the polarization control hand stage switching to either state of the two directions perpendicular linear polarization plane, the polarization control hand stage or al of the two optical When the light along the axes is input, the light is output in the bypass mode along the corresponding optical axis, and the luminous flux propagating along one optical axis is in one of the two polarization directions.
Equipped with two inputs and two output optical switch having an optical path shift means to output the light in extensin-change mode to the optical path shift by the diffraction to propagate along the other optical axes, two the two inputs and two outputs optical switch constitute the optical space switch stage portion arranged in parallel such that the incident surface to each other is parallel to the second optical space switch step portion for the first optical space switch stage section is rotated 90 degrees state A spatial light switch device comprising: a spatial light switch; 7. A in two mutually parallel optical axes, and the polarization control hand stage switching to either state of the two directions perpendicular linear polarization plane, the polarization control hand stage or al of the two optical When the light along the axes is input, the light is output in the bypass mode along the corresponding optical axis, and the luminous flux propagating along one optical axis is in one of the two polarization directions.
Equipped with two inputs and two output optical switch having an optical path shift means to output the light in extensin-change mode to the optical path shift by the diffraction to propagate along the other optical axes, two the two inputs and two outputs optical switch A spatial light switch device having a structure in which the spatial light switch steps are arranged in parallel so that their incident surfaces are parallel to each other, and these spatial light switch steps are stacked in four stages; In the plane, the first adjacent channel interval is d, channel 0 is (0, d), channel 1 is (d, d), channel 2 is (d, 2d), channel 3 is (2d, 2d),
Channel 4 is (d, 0), channel 5 is (2d, 0),
Channel 6 is (2d, d), Channel 7 is (3d, d)
Disposed in the first optical space switch stage unit, the channel 0 channel 4, channel 1 channel 5, the channel 2 channel 6, a beam shift structure between the channel 3 channel 7 is provided, the second spatial light in the third optical space switch stage unit and Contact switch stage portion, respectively the channel 0 channel 2, channel 1
−Channel 3, Channel 4−Channel 6, Channel 5−
A beam shift structure between channel 7 provided, arranged at the fourth optical space switch stage unit, the channel 0 channel 1, channel 2 channel 3, channel 4 channel 5, a beam shift structure between the channel 6 channel 7 A spatial optical switch device comprising an eight-input eight-output banyan net-type spatial optical switch. Between 8. optical space switch stage of the third spatial light switch stage of the fourth hand stage for rotating the plane of polarization 45 degrees and wherein the interposed , Claim 7
The spatial light switch device according to claim 1. 9. A in two mutually parallel optical axes, and the polarization control hand stage switching to either state of the two directions perpendicular linear polarization plane, the polarization control hand stage or al of the two optical When the light along the axes is input, the light is output in the bypass mode along the corresponding optical axis, and the luminous flux propagating along one optical axis is in one of the two polarization directions.
Equipped with two inputs and two output optical switch having an optical path shift means to output the light in extensin-change mode to the optical path shift by the diffraction to propagate along the other optical axes, two of the 2 input 2 output optical switch A spatial light switch step is formed by arranging a plurality of the two-input and two-output optical switches so that the surfaces formed by the optical axes parallel to each other are parallel to each other. A spatial optical switch device having an 11-stage cross-banyan network equivalent circuit structure, wherein d is an adjacent channel interval, channel 0 is (0, 0), and channel 1 is (0, 0). 0, -2d), channel 2 at (2d, 0), and channel 3 at (2d, -2).
d), channel 4 is (d, -d), and channel 5 is (d, -d).
-3d), channel 6 is (3d, -d), channel 7 is (3d, -3d), channel 8 is (d, 0), channel 9 is (d, -2d), and channel 10 is (3d, 0). ), Channel 11 is (3d, -2d), and channel 12 is (0,
-D), channel 13 is (0, -3d), channel 14
At (2d, -d) and channel 15 at (2d, -3d). In the first, fourth, seventh and tenth spatial optical switch stages, channels 0-2, 4-6, 1- 3,5-7,8-10,12-
14, 9-11, and 13-15 are switchable. In the second, fifth, eighth, and eleventh spatial optical switch stages, channels 0-1, 4-5, 2-3, 6-7, 12-13, 8-
9, 14-15, and 10-11. The third and ninth spatial optical switch stages have channels 0-4,
1-5, 2-6, 3-7, 8-12, 9-13, 10-
14, 11-15, and in the sixth spatial optical switch stage, channels 0-8, 12
-4,1-9,13-5,2-10,14-6,3-1
NB (I) is the I-th bit in the binary representation of each node in each stage, and FB (J) is the J-th binary representation of the destination node. , And PS is 0 for P-polarized light and 1 for S-polarized light, and SC is a polarization control switch state. In the first, fourth, seventh and tenth spatial light switch stages, SC = PS XOR (NB (3) XOR FB (3)) In the second, fifth, eighth and eleventh spatial optical switch stages, SC = PS XOR (NB (4) XOR FB (4)) third and ninth SC = PS XOR (NB (2) XOR FB (2)) in the spatial light switch stage of the above. SC = PS XOR (NB (1) XOR FB (1)) in the sixth spatial optical switch stage Characterized in that a polarization switch setting is given to the Optical switching device. During 10. Two mutually parallel optical axes, and the polarization control hand stage switching to either state of the two directions perpendicular linear polarization plane, the polarization control hand stage or al of the two optical When the light along the axes is input, the light is output in the bypass mode along the corresponding optical axis, and the luminous flux propagating along one optical axis is in one of the two polarization directions.
Equipped with two inputs and two output optical switch having an optical path shift means to output the light in extensin-change mode to the optical path shift by the diffraction to propagate along the other optical axes, two of the 2 input 2 output optical switch A spatial light switch step is formed by arranging a plurality of the two-input and two-output optical switches so that the surfaces formed by the parallel optical axes are parallel to each other. A spatial optical switch device having an equivalent circuit structure of a nine-stage expanded deformed Banyan network which is separated and stacked, where d is an adjacent channel interval, channel 0 is (0, 0), and channel 1 is ( d, -d), channel 2 is (0, -2d), channel 3 is (d, -3d),
Channel 4 is (2d, 0) and channel 5 is (3d,-
d), channel 6 is (2d, -2d), channel 7 is (3d, -3d), channel 8 is (d, 0), channel 9 is (0, -d), and channel 10 is (d, -2d). ), Channel 11 is (0, -3d), and channel 12 is (3d,
0), the channel 13 is arranged at (2d, -d), the channel 14 is arranged at (3d, -2d), and the channel 15 is arranged at (2d, -3d). In the first and sixth spatial optical switch stages, Channels 0-4,
1-5, 2-6, 3-7, 8-12, 9-13, 10-
14, 11-15, and the second, third, seventh, and eighth spatial optical switch stages have channels 0-2, 1-3, 4-6, 5-7, and 9-11. , 8-1
0, 13-15, and 12-14. The fourth and ninth spatial optical switch stages have channels 0-1,
2-3, 4-5, 6-7, 8-9, 10-11, 12-
13, 14-15, and the fifth spatial optical switch stage has channels 0-8, 1-
9, 2-10, 3-11, 4-12, 5-13, 6-1
NB (I) is the I-th bit in the binary representation of each node at each stage, and FB (J) is the J-th binary representation of the destination node. When the polarization of a beam incident on a certain node is P-polarized light and S-polarized light is 1 and SC is a polarization control switch state, the first, third, fourth, sixth, ninth spatial light switches In the step section, SC = PS XOR (NB (M) XOR FB (M)) (M = 2,3,4,2,3,4 in the order of each step section) In the second and seventh spatial light switch steps, SC = PS XOR (NB (3) XOR FB (3)) In the fifth spatial light switch stage, the polarization switch setting is given as SC = PS XOR (NB (1) XOR FB (1)) A spatial light switch device, characterized in that: 11. A in two mutually parallel optical axes, and the polarization control hand stage switching to either state of the two directions perpendicular linear polarization plane, the polarization control hand stage or al of the two optical When the light along the axes is input, the light is output in the bypass mode along the corresponding optical axis, and the luminous flux propagating along one optical axis is in one of the two polarization directions.
Equipped with two inputs and two output optical switch having an optical path shift means to output the light in extensin-change mode to the optical path shift by the diffraction to propagate along the other optical axes, two of the 2 input 2 output optical switch By arranging a plurality of the two-input and two-output optical switches so that the surfaces formed by the optical axes parallel to each other are parallel to each other, a spatial optical switch step is formed. A space configured to have an equivalent circuit structure of an eight-input modified banyan network divided and stacked, and to expand by combining a plurality of the eight-input modified banyan networks, thereby to have an equivalent circuit structure of a 2 ⁿ -input extended modified banyan network. An optical switch device, wherein for the 8-input modified Banyan network, NB (I) is an I-th bit in a binary representation of each node in each stage, and
Let B (J) be the J-th bit of the binary representation of the destination node, let PS be 0 for P-polarized light, 1 for S-polarized light, and let SC be the polarization control switch state, In the spatial light switch stages 1, 3, and 4, SC = PS XOR (NB (M) XOR FB (M)) (M = 1, 2, 3 in order of each stage) Second spatial optical switch stage A spatial light switch device, wherein a polarization switch setting is provided as in SC = PS XOR FB (2). 12. In the case where N of 2 ^{N + 2} inputs is an odd number, first, a 2 ^{N + 2} channel arrangement and a left-right symmetric arrangement are separately formed, and the original channel arrangement and row arrangement are added to the separately formed channel arrangement. And the order in the row is preserved, and a channel number of 2 ^{N + 2} or more is assigned, and then the two channel arrangements are overlapped to form an arrangement of 2 ^{N + 3} channels. The spatial light switch device according to claim 11, wherein the spatial light switch device is extended. 13. In a case where N of 2 ^{N + 2} inputs is an even number, first, the same arrangement as the 2 ^{N + 2} channel arrangement is separately formed, and the newly formed channel arrangement is added to the original channel arrangement row and the row in the row. By preserving the order and assigning channel numbers of 2 ^{N + 2} or more, the two channel arrangements are shifted in two directions by half of the minimum channel interval d and overlapped to form an arrangement of 2 ^{N + 3} channels, 12. The spatial light switch device according to claim 11, wherein a plurality of said eight-input modified Banyan nets are combined and extended. To 14. In two mutually parallel optical axes, and the polarization control hand stage switching to either state of the two directions perpendicular linear polarization plane, the polarization control hand stage or al of the two optical When the light along the axes is input, the light is output in the bypass mode along the corresponding optical axis, and the luminous flux propagating along one optical axis is in one of the two polarization directions.
By having an optical path shift means to output the light in extensin-change mode to the optical path shift by the diffraction to propagate along the other optical axis, characterized in that it constitutes a 2-input 2-output optical switches , Spatial light switch device. 15.該光Ro shift hands stage provided with a first diffraction grating layer contact and the second diffraction grating layer arranged in parallel at intervals from each other, with grating vector diffraction grating is different for each layer constituted by two planes diffraction grating, for the S-polarized light, is shifted beams by diffracting the second diffraction grating layer and contact the first diffraction grating layer above,
For P-polarized light, the first and the first diffraction grating layer up for the 2
Characterized in that it is configured to transmit also the diffraction grating layer, optical space switch device according to claim 14. 16. The light beam the diffraction grating is incident vertically with the only polarized direction required angle by Bragg diffraction,
The spatial light switch device according to claim 14, wherein the lattice stripes are inclined in a thickness direction. 17. The light beam the diffraction grating is incident vertically with the only polarized direction required angle by Bragg diffraction,
16. The spatial light switch device according to claim 15, wherein the cross-sectional shape of the grating is configured to have asymmetry. 18. The angle of polarization direction by Bragg diffraction light beams the diffraction grating is incident perpendicularly, characterized in that it is set to 48.2 degrees, the spatial light switching device according to claim 17. 19. The difference between the refractive index modulation Δn of the diffraction grating, the wavelength λ, and the thickness D of the diffraction grating is Δn · D · cos4.
19. The spatial light switch device according to claim 18, wherein 8.2 ° = π · λ is established. 20. a respective diffraction grating layer above, wherein the holographic diffraction grating is used,
The spatial light switch device according to claim 15. 21. polarizing control hand stage, liquid crystals sandwiched between a transparent electrode, is constructed as a means of controlling the polarization state by applying a voltage, and, on a substrate transparent electrodes sandwiching the liquid crystal is formed, said The spatial light switch device according to claim 15, wherein the diffraction grating layer is formed integrally. 22. Oite the second diffraction grating layer and contact the first diffraction grating layer has the same spatial frequency, the direction of the grating vector are equal, eliminating boundary by connecting the area of the diffraction grating proximate The spatial light switch device according to claim 15, wherein the spatial light switch device is configured as described above. 23. Oite the second diffraction grating layer and contact the first diffraction grating layer, all channels are configured so as to be surrounded by boundaries having a predetermined width where the diffraction grating is not formed The spatial light switch device according to claim 15, wherein: 24. Along with the first diffraction grating layer is formed integrally on one surface of the transparent flat plate, and wherein the diffraction grating layer of said second integrally provided on the other surface of the transparent Akirataira plate Do
The spatial light switch device according to claim 15.