JP2742550B2 - Multi-terminal optical switch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multi-terminal optical switch having a function of arbitrarily converting the spatial arrangement order of a plurality of collimated light beams propagating in space.

2. Description of the Related Art Light that arbitrarily switches between a number of input terminals and a number of output terminals by converting the polarization state of a light beam propagating in space from a P wave to an S wave or an S wave to a P wave. A matrix switch has been conventionally proposed. In FIG.
The structure of this optical matrix switch is shown. In this figure, I, I ... are input light beams, OT, OT ... are output light beams, 1,
Are input-side polarization plane control elements, 2, 2 are output-side polarization plane control elements, and 3, 3 are polarization beam splitters. The polarizing beam splitter 3 passes the P wave passing in the horizontal direction and the vertical direction in the drawing, and refracts the S wave by 90 degrees. In the OFF state, the polarization plane control elements 1 and 2 do not affect the polarization plane of the passing light, and in the ON state, rotate the polarization plane of the passing light by 90 degrees to convert the P wave into the S wave. Convert S wave to P wave. It is assumed that all input light beams I of the optical matrix switch are P waves.

In order to take out the i-th input light beam in the figure as the j-th output light beam using this optical matrix switch, a polarized beam located at the intersection of the i-th input light beam and the j-th output light beam Both the input-side polarization plane control element 1 and the output-side polarization plane control element 2 of the splitter 3
What is necessary is just to set it to ON, and to set all other polarization plane control elements 1 and 2 to OFF. At this time, the light beam that has reached the polarization beam splitter 3 is converted into an S-wave by the input-side polarization plane control element 1, refracted by 90 degrees by the polarization beam splitter 3, and again output by the output-side polarization plane control element 2. It is converted into a wave and output as an output light beam OT.

This matrix switch can realize a switching circuit having n input terminals and n output terminals with a simple configuration.
However, since n ² polarization beam splitters are required for the number of terminals n, the number of components becomes very large as n increases. In addition, since the light beam passes through many polarization beam splitters 3 and the input-side and output-side polarization plane control elements 1 and 2, there is a disadvantage that a transmission loss increases.

On the other hand, unit switches of 2 inputs and 2 outputs are connected in multiple stages,
The 2 ⁿ input terminals and the 2 ⁿ Configuration of switching network which can realize all combinations of connecting one-to-one between the output terminal has been devised. FIG. 9 is a wiring diagram of an 8-input / 8-output switch network based on the above configuration method.
In this figure, solid lines indicate wiring in the network. The rectangle is a unit switch having two inputs and two outputs, and a connection form (through) between input 1 and output 1 and input 2 and output 2 and input 1 and output 2 and input 2 and output 1 are controlled by external control. (Cross).

Switch network shown in FIG. 9 can be easily extended to the 2 ⁿ input terminals and switch network having a 2 ⁿ pieces of output terminals. This expansion is achieved by arranging two switch networks each having 2 ^n-1 terminals in parallel, providing a unit switch stage in front of the switch network for distributing two outputs one by one to each of the two switch networks, and a subsequent stage. Is provided by providing a unit switch stage for receiving one input from each of the two switch networks. Here, the two output terminals of the i-th unit switch of the first stage are connected to the i-th unit switch of the next stage and the i + 2 ^n-1 (when i ≦ 2 ^n-1 ) or i−2 ⁿ⁻¹ (When i> 2 ^n-1 )
And the unit switch of the last stage, i
The two output terminals of the i-th unit switch are connected to the i-th unit switch of the last stage and the (i + 2 ^n-1) -th (when i ≦ 2 ^n-1 ) or i-2 ^n-1 (i> 2 ^n-) If the connection is made at ¹ ), the above condition is satisfied.

FIG. 10 shows wiring when the number of input terminals and the number of output terminals are set to ²⁵ = 32 as an example of the above-mentioned expansion of the switch network. The area indicated by reference numeral G in the figure has the same configuration as the 8-input / 8-output switch network shown in FIG. The area indicated by reference numeral G1 forms a 16-input / 16-output switch network configured according to the above-described extended algorithm. The entire switch network shown in FIG. 10 is obtained by further expanding this switch network by the above algorithm. As is apparent from the above algorithm and FIG. 10, in general, a switch network having 2 ⁿ input terminals and output terminals includes 2 ^n-1 unit switches per stage (2n-1 ) The position of one unit switch array and one of the outputs of each cross-connect switch are spatially shifted by one, two, four... ^2n-2 in the next-stage switch array. Each of the wiring networks connected to the switches is constituted by a total of (2n-2) wiring networks.

As a unit switch for optically realizing the above switch network, there is a unit switch in which the rotation of the polarization plane of the passing light beam by the polarization plane control element corresponds to the operation of the unit switch. FIG. 11 is a diagram showing the configuration of such a unit optical switch. In FIG. 11, reference numerals 11-1 and 11-2 denote polarization beam splitters, and reference numeral 12 denotes a polarization plane control element. Ip and Is are incident polarization beams, respectively, Ip is a P wave, and Is is an S wave. OTp and OTs are respectively outgoing polarized beams, OTp is a P wave,
OTs are S waves.

In FIG. 11, when the polarization plane control element 12 is OFF, the plane of polarization of the passing light beam does not change, and the incident light beam Ip, which is a P wave, becomes the outgoing light beam OTp as a P wave as it is, and is an S wave. The incident light beam Is becomes the output light beam OTs. On the other hand, when the polarization plane control element 12 is ON, the polarization plane of the passing light beam is rotated by 90 degrees, and the incident light beam
Is converted into an S-wave to be an outgoing light beam OTs, and the incident light beam Is, which is an S-wave, is converted into a P-wave and output light beam OTp
Becomes This operation is based on the assumption that the input light beams Ip and Is are two inputs and the output light beams OTp and OTs are two outputs.
The operation is exactly the same as the operation of the unit switch defined in the description of FIG.

[Problems to be Solved by the Invention] By the way, when the above-described switch network (FIGS. 9 and 10) is configured using the polarization plane control element as a switch element, wiring between the unit optical switch stages is required. Must be set. Generally, this wiring separates outgoing light beams from each unit optical switch into P-waves and S-waves, synthesizes each with the other incident light beam of the next-stage unit optical switch, and forms the next-stage unit light switch. It needs to be incident on the optical switch. For a switch network having 2 ⁿ input terminals and output terminals, if this light beam is separated and combined using a polarization beam splitter, 2 ⁿ polarization beam splitters are required per wiring network stage. Become. Therefore, when the wiring network using the polarization beam splitters is adopted, 2 ⁿ (2n−2) polarization beam splitters are required in the entire switch network, and the number of required components becomes very large as the number of terminals increases. .

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a simple and compact multi-terminal optical switch for switching a plurality of collimated light beams propagating in free space.

Means for Solving the Problems The first invention is directed to a polarization plane on which a plurality of incident signal lights having only a first linear polarization component among first and second linear polarization components different from each other by 90 degrees are incident. A control element, which receives the incident signal light as it is or changes its polarization plane in accordance with external control.
A polarization plane control element that is rotated by 90 degrees to pass therethrough, and an optical path of signal light into which light that has passed through the polarization plane control element is incident and has one of the first and second linear polarization components Is converted to a right angle direction, and the other light path conversion element that passes the signal light having the linear polarization component as it is, the light path conversion of 90 degrees by the light path conversion element is made incident light, of the incident signal light An optical path is changed to be parallel, the traveling direction is reversed, and a first reflection element for rotating the polarization plane by 90 degrees, and light that has passed straight through the optical path conversion element and is incident, the incident signal The present invention is characterized in that a light is made to travel in the opposite direction, the polarization plane is rotated by 90 degrees, and a second reflection element is provided.

Further, the second invention provides a plurality of first linear polarization components having a first linear polarization component among the first and second linear polarization components different from each other by 90 degrees.
The signal light is incident in parallel, and the optical path of the first signal light is
A plurality of second signal lights having a second linearly polarized light component are incident from different directions, and while the first signal light is traveling straight, the optical path of the second signal light is converted by 90 degrees to convert the first signal light and the first signal light. The multi-terminal optical switch according to claim 1, wherein the first optical path conversion element that combines and emits the second signal light and the signal light emitted from the first optical path conversion element are connected in multiple stages. Signal light passing through these multi-terminal optical switches is incident, and a polarization plane control element for passing the signal light as it is or by rotating the polarization plane by 90 degrees under external control, and an output of the polarization plane control element. An optical path conversion element that receives incident light, converts the optical path of the signal light having one of the first and second linearly polarized light components into a right angle direction, and straightly advances the signal light having the other linearly polarized light component. Characterized by having

Conventional optical switch "action" is needed for the 2 ⁿ switching network having an input terminal and an output terminal, the 2 ⁿ pieces of the polarizing beam splitter wiring network per stage for the separation of the light beam combining On the other hand, in the present invention, one polarization beam splitter per one stage of the wiring network can realize the same function as the conventional optical switch, so that an optical switch having a large number of terminals can be easily realized.

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention. In this figure, 21 is a polarization plane control element, and 22 is a polarization beam splitter (optical path conversion element). Reference numerals 23 and 55 denote polarization plane rotating elements that exchange two orthogonal linearly polarized light components by passing through the element twice. Reference numeral 24 denotes an umbrella-shaped reflector that reverses the signal direction of incident light and shifts its optical path, and exchanges the optical path between any two signals.
26 is a total reflection mirror. Here, the polarization plane rotation element 23 and the reflection plate 24 replace the first reflection element 27 with the polarization plane rotation element 25.
The total reflection mirror 26 constitutes a second reflection element.

In such a configuration, when the incident signal light that is incident from the direction of the arrow Y1 shown in the drawing and passes through the polarization plane control element 21 is a P wave (Ip), the signal light Ip is transmitted to the polarization beam splitter 22.
And exits in the direction of arrow Y3. On the other hand, when the incident signal light that has passed through the polarization plane control element 21 is an S-wave (Is),
The light is refracted, passes through the polarization plane rotation element 23, the reflection plate 24, and the polarization plane rotation element 23, is converted into a P-wave, the optical path is shifted in parallel, and then enters the polarization beam splitter 22 again.
Then, the incident signal light passes through the polarization beam splitter 22 as it is, and a polarization plane rotation element 25, a total reflection mirror 26,
The light is converted into an S-wave through the polarization plane rotation element 25, and is again incident on the polarization beam splitter 22. This signal light (S wave) is refracted by 90 degrees by the polarization beam splitter 22 and emitted in the direction of arrow Y4.

Similarly, the light is incident from the direction of the arrow Y2,
If the signal light that has passed through is a P-wave, it is emitted in the direction of arrow Y4, and if it is an S-wave, it is emitted in the direction of arrow Y3.

As a result, P waves are respectively incident from the directions of arrows Y1 and Y2,
When the polarization plane control element 21 is set to the OFF state, the signal light from the arrow Y1 is emitted in the direction of the arrow Y3 and the signal light from the arrow Y2 is emitted in the direction of the arrow Y4 (through). Is turned on, the signal light from arrow Y1
Signal light from the arrow Y2 is emitted in the direction of arrow Y2 (cross). That is, according to the configuration of FIG.
A two-input / two-output unit optical switch is configured.

According to the above-described structure, a plurality of sets (two sets in the case of FIG. 6) of two-input / 2-output unit optical switches are realized by one configuration shown in FIG. 1, as shown in FIG. can do.

Embodiment 2 FIG. 2 is a view showing a second embodiment of the present invention. In this figure, 31 is a polarization plane control element, 32 is a polarization beam splitter (optical path conversion element), 33 and 35 are the polarization plane rotation elements described in FIG. 1, 34 is an umbrella-type reflector, and 36 is a total reflection mirror. is there. Here, the polarization plane rotation element 33 and the reflection plate 34 constitute a first reflection element 37, and the polarization plane rotation element 35 and the total reflection mirror 36 constitute a second reflection element.

In such a configuration, light is incident from the arrow Y1 direction,
When the signal light passing through the polarization plane control element 31 is a P wave (Ip), the signal light Ip passes through the polarization beam splitter 32 as it is, and is converted into S-polarized light by the polarization plane rotation element 35 and the total reflection mirror 36. The beam again enters the polarization beam splitter 32, is refracted by the polarization beam splitter 32 in a direction of 90 degrees, and is emitted in the direction of the arrow Y3. On the other hand, when the incident signal light is an S-wave (Is), the signal light Is is refracted in the 90-degree direction by the polarization beam splitter 32, and its optical path moves in parallel by the polarization plane rotation element 33 and the reflection plate 34. The light is converted into a P-wave and transmitted through the polarizing beam splitter 32, and is indicated by an arrow Y4 in FIG.
It is emitted in the direction.

Similarly, the light is incident from the direction of the arrow Y2,
If the signal light that has passed through is a P-wave, it is emitted in the direction of arrow Y4, and if it is an S-wave, it is emitted in the direction of arrow Y3.

Thus, even with the above configuration, a two-input / two-output unit optical switch similar to that of FIG. 1 is configured. In addition, according to the above-described structure, as shown in FIG.
With one configuration, it is possible to realize a plurality of sets (two sets in the case of FIG. 7) of two-input / two-output unit optical switches.

Next, a configuration example of the reflecting elements 27 and 37 used in the first and second embodiments will be described. FIG. 3, FIG. 4,
FIG. 5 shows a polarization plane rotation element that exchanges two orthogonal linear polarization components by passing through the element twice, an incident light traveling direction is reversed, and its path is shifted. An example of the configuration of a reflective element combining a reflector for exchanging the optical path between two signals is shown. In these examples, the umbrella-type reflector is doubled.

In FIG. 3, 41 to 44 are reflection plates, and 45 and 46 are half-wave plates (polarization plane rotating elements). The incident light I is first incident on a reflector 41 having a normal inclined at 45 degrees to the incident light I, its optical path is changed by 90 degrees, and then incident on the reflector 42, and its optical path is again turned by 90 degrees. Is converted. In other words, the incident signal light I is refracted twice by 90 degrees by the two reflectors 41 and 42, the traveling direction is reversed, and the optical path is shifted and emitted. The output signal light enters the half-wave plate 45, where its polarization plane is rotated by 90 degrees.

FIGS. 4 and 5 use a quarter-wave plate 51 and a Faraday rotator 52 instead of the half-wave plates 45 and 46 (polarization plane rotators) in the reflection element of FIG. And 2
When the incident light and the outgoing light to the two reflectors pass through these polarization plane rotation elements, the outgoing signal light of the reflecting element is converted to light having a polarization plane orthogonal to the polarization plane of the incident signal light.

Embodiment 3 FIG. 6 is a view showing a third embodiment of the present invention, and FIG.
The unit optical switches shown in FIG.
This is an example in which functions equivalent to those of the 8-input / 8-output optical switch network shown in the figure are realized. In FIG. 6, 61-1 to 61-
6 is a polarization beam splitter, 62-1 to 62-5 are polarization plane control elements, 63-1 to 63-8 are polarization plane rotation elements, and 64-1 to 64.
Reference numeral -4 denotes a reflection plate that reverses the traveling direction of the incident light and shifts its path, and reference numerals 65-1 to 65-4 denote total reflection mirrors. Reference numerals 66-1 to 66-4 denote P-wave incident signal lights, which are incident signal lights 26-1, 26-3, 26-7, and FIG.
26-5 respectively. Reference numerals 67-1 to 67-4 denote incident signal light of S-wave, and the incident signal light 26- in FIG.
2, 26-4, 26-8 and 26-6 respectively.
68-1 to 68-4 are emission signal lights of P wave, and 69-1 to 69-4 are emission signal lights of S wave.

In such a configuration, the incident signal light 66-1, 67-1
Are combined by the polarization beam splitter 61-1 and are incident on the polarization plane control element 62-1. Polarization control element 62−
When 1 is OFF, the incident signal light 66-1 of the P wave passes through the polarization beam splitter 61-2 as it is and enters the polarization plane control element 62-2 at the next stage. Also, the incident signal light 67-1 of the S wave
The optical path is changed by 90 degrees by the polarization beam splitter 61-2, and the optical path is shifted in parallel and the direction is reversed by the reflection element composed of the polarization plane rotation element 63-1 and the reflection plate 64-1. And converted to a P-wave,
Next, the light goes straight through the polarization beam splitter 61-2, and its direction is reversed by a reflection element constituted by the polarization plane rotation element 63-1 and the total reflection mirror 64-1, and is converted into an S wave. In the splitter 62, the optical path is changed by 90 degrees again, multiplexed with the P-wave incident signal light 66-4, and is incident on the polarization plane control element 62-2 in the next stage. The above operation is equivalent to the optical switch 21-1 in the through state in FIG.

On the other hand, when the polarization plane control element 62-1 is ON, the incident signal light
67-1 is converted into a P wave by the polarization plane control element 62-1 and passes through the polarization beam splitter 61-2 as it is, and enters the polarization plane control element 62-2 at the next stage. On the other hand, the incident signal light 66−
1 is converted into an S-wave by the polarization plane control element 62-1 and is incident on the polarization beam splitter 61-2, where it is refracted and, as a result, is multiplexed with the incident signal light 66-4, so that the next stage polarization plane control element It is incident on 62-2. The above state is equivalent to the optical switch 21-1 in the cross state in FIG.

The above operation is the same for other incident signal lights, and also for each unit optical switch connected in multiple stages. According to the configuration of FIG. 6, the incident signal lights 66-1 to 66-4, 67-1 to 67-4 are respectively output from the output signal lights 68-1 to 68-4, 69-1 to 69-4. Can be connected to the desired outgoing signal light. For example, the incident signal light 66−
1 is connected to the output signal light 68-1, the polarization plane control element
It is sufficient that all of 62-1 to 62-5 are turned off.
In order to connect 6-1 to the outgoing signal light 68-2, the polarization plane control elements 66-1, 66-4, 66-5 may be turned off and 66-2, 66-3 may be turned on. In order to connect the signal light 66-1 to the output signal light 69-3, the polarization plane control elements 66-1 and 66-5 are turned off and 66-
2 to 66-4 may be turned ON.

In the switch network of FIG. 6, the two output terminals of the i-th unit optical switch in the first stage are respectively connected to the i-th unit optical switch in the next stage and the 2 ⁿ (i-1) -th unit optical switch. Connected and connected to the i-th unit optical switch 2
The output terminals of this are the i-th unit optical switch of the last stage and 2 ⁿ
FIG. 9 is different from FIG. 9 in that it is connected to the (i-1) th unit optical switch, respectively. This is because the unit optical switches 21-3 and 21-4, 22-3 and 22- in FIG. 4,
23-3 and 23-4, 24-3 and 24-4, and 25-3 and 25-4 correspond to the switch network, respectively. The switch network of FIG. 6 is essentially the switch network of FIG. It is equivalent to a net.
The switch network shown in FIG. 6 has different position shift amounts (n−
1) The number of unit switches two by two, a total of 2 (n-1) pieces unit switches only Tile cascade, readily to the 2 ⁿ input terminals and Suittchi network having a 2 ⁿ pieces of output terminals Can be extended. The multi-terminal optical switch according to the present embodiment utilizes a polarization plane control element for light and a polarization beam splitter, and does not impose any restrictions on the signal speed of signal light. Therefore, in this embodiment, it is possible to realize a small-sized multi-terminal optical switch with a simple configuration without impairing the high speed of light.

FIG. 6 shows the switching between the one-dimensionally arranged incident signal lights, but the incident signal lights 66-1 to 66-.
4, 67-1 to 67-4 are respectively arranged in a grid pattern,
It can be seen that switching between -1 and 64-4 by 90 degrees around a line passing through the vertex of the reflector and parallel to the light incident on the reflector allows switching between the signal lights arranged in a lattice.
Therefore, the present embodiment enables arbitrary switching between two-dimensionally arranged incident signal lights, and can easily realize a high-density and small-sized switch network.

Embodiment 4 FIG. 7 shows a fourth embodiment. What is shown in this figure is
In this case, the unit optical switches shown in the second embodiment are connected in multiple stages to realize the 8-input / 8-output switch network shown in FIG. In this figure, 71-1 to 71-6 denote polarization beam splitters, 72-1 to 72-5 denote polarization plane control elements, 73-1 to 73-8 denote polarization plane rotation elements, and 74-1 to 74-4.
Is a reflection plate, and 75-1 to 75-4 are total reflection mirrors. 76-1 to 76-4 are P-wave incident signal light, and 77-1 to 77-
Reference numeral 4 denotes an S-wave incident signal light, 78-1 to 78-4 denote P-wave output signal lights, and 79-1 to 79-4 denote S-wave output signal lights.

In such a configuration, the incident signal light 76-1 of the P wave,
76-2, 76-3, and 76-4 are the incident signal lights 26 in FIG.
-1, 26-3, 26-7, and 26-5, respectively, and S-wave incident signal light 77-1, 77-2, 77-3, 77-4.
Are incident signal lights 26-2, 26-4, 26-8,
26-6 respectively. Then, the incident signal light 76
-1, 77-1 are multiplexed by the polarization beam splitter 71-1 and are incident on the polarization plane control element 72-1. When the polarization plane control element 72-1 passes the polarization planes of the incident signal lights 76-1 and 77-1 without changing each, the incident signal light 76-1 of the P wave passes through the polarization beam splitter 71-2 as it is. Then, the light is converted into S-polarized light by the polarization plane rotation element 73-2 and the total reflection mirror 75-1, and is again converted to the polarization beam splitter 71-
2, and then refracted in the direction of 90 degrees by the same polarization beam splitter 71-2, and emitted downward in the figure. The S-polarized incident signal light 77-1 is refracted in the 90-degree direction by the polarization beam splitter 71-2, and its path moves in parallel by the polarization plane rotation element 73-1 and the reflection plate 74-1. Polarized beam splitter 71
-2, and is emitted downward in the figure. The optical path of the outgoing light of these incident signal lights 76-1 and 77-1 is a polarization plane control element.
72-1 coincides with the optical path of the outgoing light of the incident signal light 77-4, 76-4 when the incident signal light passes through the polarization plane without being changed. This is the optical switch 21 in FIG.
-1 is equivalent to being in a through state. On the other hand, when the polarization plane control element 72-1 converts the polarization planes of the incident signal lights 76-1 and 77-1 respectively, and sets the incident signal light 76-1 to the S wave and 77-1 to the P wave, the P wave The incident signal light 77-1 passed through the polarization beam splitter 71-2 as it is, is converted into S-polarized light by the polarization plane rotation element 73-2 and the total reflection mirror 75-1, and is again transmitted to the polarization beam splitter 71-2. The light is then refracted in the direction of 90 degrees by the polarizing beam splitter 71-2 and emitted downward in the figure. Further, the incident signal light 76-1 converted into the S wave is transmitted to the polarization beam splitter 71-2.
Is refracted in the 90-degree direction by the polarization plane rotating element 73-1 and the reflection plate 7-41, the optical path of which is parallel-translated, further converted into a P-wave, and goes straight through the polarization beam splitter 71-2. Is emitted. These incident signal lights 76-1, 77-
The optical path of the outgoing light 1 is the incident signal light 76-7 when the polarization plane control element 72-1 does not exchange the polarization plane of the incident signal light.
4, 77-4. This is equivalent to the optical switch 21-1 in the cross state in FIG.

The above operation is the same for other incident signal light,
The same applies to each unit optical switch connected in multiple stages. Then, according to the configuration of FIG. 7, the incident signal light 76
-1 to 76-4 and 77-1 to 77-4 are respectively output signal lights 78-1.
78-4, 79-1 to 79-4.

In the switch network of FIG. 7, two output terminals of the i-th unit optical switch in the first stage are connected to the i-th unit switch in the next stage and the 2 ^n- (i-1) -th unit switch, respectively. The two output terminals of the i-th unit optical switch in the preceding stage of the last stage are connected to the i-th unit optical switch in the last stage and 2 ⁿ −
FIG. 9 is different from FIG. 9 in that it is connected to the (i-1) th unit optical switch, respectively. This is because the unit optical switches 21-3 and 21-4, 22-3 and 22-4 in FIG. ,
23-3 and 23-4, 24-3 and 24-4, and 25-3 and 25-4 correspond to the switch network, respectively. The switch network of FIG. 7 is essentially the switch network of FIG. It is equivalent to a net.
The switch network of FIG. 7 has different position shift amounts (n-
1) 2 unit optical switches, 2 (n-1) in total
In a number of unit switches only arranged in multiple stages, can be readily extended to the 2 ⁿ input terminals and switch network having a 2 ⁿ pieces of output terminals. Further, in the configuration of the present embodiment, it is possible to minimize the optical path length difference of the signal light passing through the unit optical switch when the state of the unit optical switch is the through state and the cross state.

Further, the multi-terminal optical switch having the configuration shown in the present embodiment uses a polarization plane control element of light and a polarization beam splitter, and these do not limit the signal speed of signal light at all. Therefore, in this embodiment, it is possible to realize a small-sized multi-terminal optical switch with a simple configuration without impairing the high speed of light.

FIG. 7 shows the switching between the one-dimensionally arranged incident signal lights.
4, 77-1 to 77-4 are arranged in a lattice arrangement,
It can be seen that if the −1 and 74-4 are rotated by 90 degrees around a line passing through the vertex of the reflector and parallel to the light incident on the reflector, switching between the signal lights arranged in a lattice can be realized.
Therefore, this embodiment enables arbitrary switching between two-dimensionally arranged incident signal lights, and can easily realize a high-density and small-sized switching network.

[Effects of the Invention] As described above, the multi-terminal optical switch according to the present invention uses the optical path conversion element and the reflection plate for shifting the reflection position, and is switched using the polarization plane rotation element and the total reflection mirror. In both cases when the two signal lights are in the through state and in the cross state, the path of the two output signal lights is made coincident with the path of the two incident signal lights, thereby simplifying the manufacturing and improving the device. There is an effect that the size can be reduced.

[Brief description of the drawings]

FIGS. 1 and 2 are block diagrams showing the structure of the first and second embodiments of the present invention, respectively. FIGS. 3 to 5 are first reflection elements used in the respective embodiments of the present invention. FIGS. 6 and 7 are block diagrams showing configurations of third and fourth embodiments of the present invention, respectively. FIGS. 8 to 10 are diagrams of a conventional multi-terminal optical switch. FIG. 11 is a block diagram showing a configuration example. FIG. 11 shows two inputs used in each embodiment of FIGS. 9 and 10.
FIG. 3 is a diagram illustrating a configuration example of a unit output switch of / 2 output. 21, 31 ... polarization plane control element, 22, 32 ... polarization beam splitter (optical path conversion element), 27, 37 ... first reflection element, 28,
38 second reflecting element 61-1, 71-1 polarizing beam splitter, 62-5, 72-5
... Polarization plane control element, 61-6, 71-6... Polarization beam splitter.

Claims (2)

(57) [Claims] 1. A polarization plane control element to which a plurality of incident signal lights having only a first linear polarization component among first and second linear polarization components different from each other by 90 degrees are incident. Depending on the control, the incident signal light can be used as it is or the polarization plane
A polarization plane control element that passes through the polarization plane control element after being rotated by degrees,
An optical path conversion element that converts the optical path of the signal light having one linear polarization component of the second linear polarization component in the orthogonal direction and passes the signal light having the other linear polarization component as it is, A first reflection element that receives the light that has undergone the 90-degree optical path conversion, changes the optical path of the incident signal light to be parallel, reverses the traveling direction thereof, and rotates the polarization plane by 90 degrees; A second reflection element that receives light that has passed straight through the optical path conversion element, makes the traveling direction of the incident signal light reverse, and rotates the polarization plane by 90 degrees. Terminal optical switch. 2. A plurality of first signal lights having a first linearly polarized light component among first and second linearly polarized light components different from each other by 90 degrees are incident in parallel, and an optical path of the first signal light and a plurality of first signal light beams having a first linearly polarized light component. A plurality of second signal lights having a second linear polarization component are incident from different directions, and the second signal light is caused to travel straight, while the second signal light is caused to travel straight.
The optical path of the signal light is converted by 90 degrees and the first signal light and the second
The multi-terminal optical switch according to claim 1, wherein the first optical path conversion element combines and emits the signal light, and the multi-terminal optical switch according to claim 1, wherein the signal light emitted from the first optical path conversion element is connected in multiple stages. The signal light that has passed through these multi-terminal optical switches is incident, and a polarization plane control element that passes the signal light as it is or by rotating the polarization plane by 90 degrees under the control of the outside, and the output light of the polarization plane control element is An optical path conversion element that is incident and converts the optical path of the signal light having one linear polarization component of the first and second linear polarization components in the orthogonal direction, and straightly advances the signal light having the other linear polarization component, A multi-terminal optical switch comprising: