JPH06230438A - Optical switch - Google Patents

Abstract

PURPOSE:To simplify operation control and to decrease driving circuits by decreasing the number of control electrodes and the number of input pins of the optical switch. CONSTITUTION:Optical switch parts SW1, SW2, SW3, SW4 have light input ports A, B and light output ports C, D. The one light output port C of the optical switch part SW1 of the input stage is connected to the one light input port A of the optical switch part SW3 and the other light output port D of the SW1 is connected to the light input port A of the optical switch part SW4. The light output port C of the other optical switch part SW2 of the input stage is connected to the light input port B of the optical switch part SW3 and the light output port D of the SW2 is connected to the light input port B of the optical switch part SW4. Absorption electrodes 10a, 10b, 11a, 11b are provided on waveguides connecting the optical switch parts to each other and the two absorption electrodes 10a and 11b and 11a and 10b are respectively connected by wirings 12, 13. Crosstalk light is absorbed by impressing electric fields to wirings 12, 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical switch having a small number of control electrodes, simple structure and operation control, and good crosstalk characteristics.

[0002]

2. Description of the Related Art As an optical switch, a multiple quantum well (Mu
little Quantum Well: Below, MQ
Abbreviated as W) Quantum well confinement effect of semiconductor material (Qua
ntum Confined Stark Effec
t: Hereinafter, abbreviated as QCSE), research on a directional coupling type optical switch utilizing an electro-optic effect caused by QCSE is under way. In such an optical switch, deterioration in characteristics due to variations in device manufacturing process, particularly deterioration in crosstalk characteristics, becomes a problem, and the manufacturing yield is significantly reduced. In order to solve this, a structure has been proposed in which an optical absorption section utilizing MQW QCSE is provided in a part of the optical switch to improve the crosstalk characteristics (Japanese Patent Application No. 4-215277 and Japanese Patent Application No. 2-15277). -220439).

FIG. 7 is a perspective view of a conventional directional-coupling type optical switch having a crosstalk suppressing function using MQW QCSE. In the figure, I is a light input part, II is an optical switch part, III is a light output part, and IV is a light absorption part. These are the i-InP cladding layer 4, the core i-MQW layer 5
Is formed on the n-InP substrate 6 in which the crystal is grown, and the respective portions are electrically separated by the separation groove 9. An n-side electrode 7 is provided on the back surface of the substrate 6. Here, when the operating wavelength is 1.55 μm, the MQW layer 5 is made of InGa
Aswell 9 mm, InAlAs barrier 5 nm, Heavy-hole exciton
The absorption peak of (on) can be set to 1.44 μm, and the switching operation can be performed and the crosstalk light can be absorbed.

The light input section I constitutes a first light input port A and a second light input port B by the two p-InP clad layers 3 formed on the i-InP clad layer 4. The optical switch part II constitutes a directional coupler with two p-InP clad layers 3, and p ⁺ -In is formed on one clad layer 3.
A GaAs cap layer 2 is provided, and a switch electrode 1 is formed on the cap layer 2. The light output section III is composed of two p-InP cladding layers 3 similarly to the light input section I, and constitutes first and second light output ports C and D, respectively. The light absorption portion IV is composed of a p ⁺ -InGaAs cap layer 2 formed on the two cladding layers 3 and two absorption electrodes 10 and 11 formed on the cap layer 2, and is arranged on the light output port C side. The first light absorbing portion E and the second light absorbing portion F arranged on the light output port D side are formed.

These operations will be described with reference to FIG. In order to perform the switch operation, an electric field may be applied between the switch electrode 1 and the n-side electrode 7 of the optical switch section II. That is, when an electric field is directly applied to the waveguide, the absorption coefficient of light is slightly shifted to the long wavelength side due to the electro-optic effect caused by the MQW layer 5. When the absorption coefficient changes, the refractive index changes due to the Kramers-Kronig relationship, and accordingly, the refractive index of the waveguide changes, thereby performing switching.

Further, in the light absorption section IV, the above-mentioned optical switch section is provided between the absorption electrode and the n-side electrode 7 which are arranged in a portion corresponding to the light output section III on the side where the crosstalk light is emitted. When an electric field larger than the electric field applied to II is applied, a stronger electro-optical effect than the above occurs as shown in FIG. 8, the absorption edge of light is shifted to the long wavelength side, and the MQW layer 5
Is the light of the operating wavelength of the optical switch (for example, wavelength 1.55 μm
Light) to reduce the crosstalk light.

For example, when the light incident from the first light input port A is emitted to the first light output port C (bar state, state where light passes through without switching), the switch electrode 1
An electric field is applied to. On the other hand, the crosstalk light generated at this time passes through the second light absorption portion F toward the light output port D, but by applying an electric field to the absorption electrode 11, the MQW layer 5 has the absorption edge as described above. Shift and absorb crosstalk light. On the other hand, when the light incident from the first light input port A is emitted to the second light output port D (cross state, light switching state), a voltage is applied to the absorption electrode 10 of the first light absorption unit E. Crosstalk light is absorbed by applying.

As described above, in the conventional optical switch, the crosstalk light can be reduced to −∞ by applying the electric field to the absorption electrodes 10 or 11, but one optical switch applies the electric field to the three electrodes. It is necessary to control, and there is a problem that the number of control electrodes and the number of input pins increase.

Although one optical switch has been described above, the above problem becomes more noticeable in a large-scale switch. The 4 × 4 switch will be described below. FIG. 9 shows a conventional 4 × 4 dilated-bened (Dilated).
-Benes) shows a non-block configuration. Here, the non-block configuration means a configuration in which lights simultaneously incident from all the input ports can be simultaneously output to an arbitrary output port. It should be noted that one square box in FIG. 9 means an optical switch section, and electrodes 10 and 11 are provided as a configuration of a light absorption section on a routing waveguide (communication waveguide) between the optical switch sections.
(FIG. 7) is provided. For example, the optical switch unit SW
Input from the first optical input unit connected to 1 and bar state (applying an electric field to the switch electrode 1 of the optical switch unit SW1)
It is assumed that the input is made to SW1 of. The main power passes through SW1 as shown by the solid line and is input to SW2. The crosstalk light generated at this time is SW3 as shown by the dotted line in the figure.
Head to. At this time, an electric field is applied to the electrode 11 (FIG. 7),
The crosstalk light can be absorbed and the crosstalk light to the SW3 can be reduced to an almost negligible level.

[0010]

As described above, according to the conventional example, a large-scale switch having an ultra-low crosstalk can be constructed.
The number of electrodes required for × N optical switch is N (3N-2)
Number (N ² switch electrodes, 2N absorption electrode (N-1))
Individual). In the case of 4 × 4, a total of 40 (16 switch electrodes, 24 absorption electrodes) and 176 (64 switch electrodes, 112 absorption electrodes) electrodes are required for 8 × 8. Therefore, there is a problem that the number of input pins increases, the chip size increases due to the increase in electrode pads, and the chip yield decreases accordingly. In addition, there are problems that control is complicated and drive circuits are increased.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and to provide an optical switch having a simple structure and a simple control, which has a good crosstalk characteristic.

[0012]

In order to achieve such an object, an optical switch according to the present invention as defined in claim 1 comprises two optical waveguides, and a guided light propagating through the two optical waveguides is provided. There are provided four optical switch sections for switching the optical path of the guided light by controlling the propagation state, and the first and second optical switch sections have at least one input optical waveguide and two output optical waveguides. The third and fourth optical switch units each include two input optical waveguides and at least one output optical waveguide, and one of the output optical waveguides of the first optical switch unit has the first optical waveguide. It is connected to one of the input optical waveguides of the third optical switch section via an absorption section,
The other of the output optical waveguides of the optical switch section is connected to one of the input optical waveguides of the fourth optical switch section via the second optical absorption section, and is used for the output of the second optical switch section. One of the optical waveguides is connected to the other of the input optical waveguides of the third optical switch section via the third optical absorption section, and the other of the output optical waveguides of the second optical switch section is the fourth optical waveguide section. In the optical switch connected to the other of the input optical waveguides of the fourth optical switch section via the second optical absorption section, the first optical absorption section and the fourth optical absorption section simultaneously emit light. It is characterized by comprising a control means for controlling so as to absorb the light and a control means for controlling so that the second light absorbing portion and the third light absorbing portion simultaneously absorb the light.

According to a second aspect of the present invention, in the optical switch according to the first aspect, means for interlocking the switching control of the first optical switch section and the control of one of the two optical absorption sections. And means for interlocking the switching control of the second optical switch unit and the control of the other set of the two sets of light absorbing units.

According to a third aspect of the present invention, in the optical switch according to the first aspect, means for interlocking the switching control of the third optical switch section and the control of one of the two optical absorption sections. And a means for interlocking the switching control of the fourth optical switch section and the control of the other pair of the two pairs of light absorbing sections.

The invention according to claim 4 is the invention according to claims 1 to 3.
The optical switch of any one of the optical switches described in (1) or a plurality of types is combined in a matrix so as to have a non-blocking configuration.

[0016]

According to the present invention, the absorption electrode of an arbitrary light absorption section can be controlled to be the same as the other absorption electrode or the switch electrode, so that the number of control electrodes and the number of input pins can be reduced and the structure can be simplified. Control can be simplified.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing an optical switch having a non-block structure using four optical switch portions for explaining the first embodiment of the present invention. FIG. 7 showing a conventional example is shown below.
The same components as those described with reference to FIG. 9 are designated by the same reference numerals, and the description of those components will be omitted or simplified. The rectangular box in FIG. 1 indicates the optical switch unit. SW1 to SW4 are first to fourth optical switch units. Reference numerals 12 and 13 are wirings that connect the two absorption electrodes. These wirings may be formed by forming an insulating film (polyimide resin or the like) on the optical switch, forming a via hole at a predetermined position, and forming it on the insulating film, as is usually done. One optical output port C of the optical switch section SW1 at the input stage is connected to one optical input port A of the optical switch section SW3, and SW1
The other optical output port D is connected to the optical input port A of the optical switch section SW4. The other optical switch SW of the input stage
The optical output port C of No. 2 is connected to the optical input port B of the optical switch unit SW3, and the optical output port D of SW2 is connected to the optical input port B of the optical switch unit SW4. As the structure of the light absorption section, the absorption electrodes 10a, 11a, 10b, and 11b are the input stages SW1 and SW2 and the subsequent stages SW3 and SW4, respectively.
It is arranged on the waveguide connecting to and. The wiring 12 electrically connects the absorption electrode 10a on the waveguide on the output port C side of the optical switch section SW1 and the absorption electrode 11b on the waveguide on the optical output port D side of the optical switch section SW2. The wiring 13 electrically connects the absorption electrode 11a on the waveguide on the output port D side of the optical switch section SW1 and the absorption electrode 10b on the waveguide on the optical output port C side of the optical switch section SW2. The electrode connected to the wiring 12 and the electrode connected to the wiring 13 have a reciprocity that an electric field is applied to one and no electric field is applied to the other.

In this configuration, the number of inputs to each optical switch is 2
Only one of the two input ports is operated at the same time, and each optical switch unit has substantially 1 input 2
Functions as an output switch.

Next, the operation of the optical switch having the above structure will be described. First, the output of the first optical switch unit SW1 is input to the third optical switch unit SW3 (the light incident on SW1 is the input port A in the optical switch unit or the input port B is in the cross state), and The output of the second optical switch unit SW2 is input to the fourth optical switch unit SW4 (the light incident on SW2 is the input port A and the optical switch unit is in the cross state,
Alternatively, in the case of the bar state at the input port B), the crosstalk light of SW1 and SW2 travels to SW4 and SW3, respectively, as shown by the dotted lines in SW1 and SW2. At this time, if an electric field is applied to the wiring 13, the two crosstalk lights are absorbed by the absorption electrode 11a and the absorption electrode 10b electrically connected thereto. On the other hand, the output of SW1 is input to SW4 (the light incident on SW1 is the input port A and the optical switch is in the cross state or the input port B is the bar state), and the output of SW2 is input to SW3 (SW
When the light incident on 2 is the input port A and the optical switch is in the bar state or the input port B is in the cross state), the crosstalk light of SW1 enters SW3, as shown by the solid line in the figure.
Since that of SW2 goes to SW4, when an electric field is applied to the wiring 12, two crosstalk lights are absorbed by the absorption electrode 10a and the absorption electrode 11b which is in electrical contact with it, so that the crosstalk suppressing operation becomes possible.

As described above, the four absorption electrodes can be controlled by the two electric fields, and it is not necessary to provide the number of external connection pins for each absorption electrode, and the number of input pins can be reduced. Further, the electric connection between the absorption electrodes may be modified so that the portions corresponding to both electrodes are connected without depending on the wiring.

FIG. 2 is a second embodiment of the present invention and is a plan view showing the structure of an optical switch in which the number of input ports of the optical switch sections SW1 and SW2 at the input stage is limited to one.
In the example in the figure, the input optical switch unit is only the input port A. In this case, using the wiring 13 and the wiring 14, the switch electrode 1 and the absorption electrode 1 of the optical switch section SW1 are used.
1a and 10b are electrically connected, and wiring 12 and wiring 15
Is used to electrically connect the switch electrode 1 of the optical switch section SW2 and the absorption electrodes 10a and 11b. This optical switch operates as follows. When the light incident from the input port of the optical switch SW1 is output to the optical switch unit SW3 and the light incident from the optical switch unit SW2 is output to SW4, an electric field is applied to the switch electrode 1 of SW1 in order to bring SW1 into the bar state. Is applied. At this time, the electric field is also applied to the absorption electrodes 11a and 10b electrically connected to the switch electrode. Here, as the structure of the light absorbing portion, the i-type of the light absorbing portion IV in FIG. 7 showing a conventional example as already described in detail in Japanese Patent Application No. 4-220439 by the present inventors.
The InP clad layer 4 is used as the clad layer 3 of the optical switch unit II.
If a thinner structure is used, the electric field strength of the light absorption section IV becomes larger than that of the optical switch section II even at the same voltage, so that the crosstalk light is sufficiently absorbed at a voltage similar to the switching voltage. it can. As a result, SW1
The crosstalk light from SW4 to SW4 and from SW2 to SW3 is absorbed by the absorption electrodes 11a and 10b. On the other hand, when the light incident from the input port of the optical switch SW1 is output to the optical switch unit SW4 and the light incident from the optical switch unit SW2 is output to SW3, the switch electrode 1 of SW2 is switched to the SW2 to bring the SW2 into the bar state. Applies an electric field. Similarly to the above, an electric field is applied to the absorption electrodes 10a and 11b connected thereto, and the crosstalk light is absorbed. In this configuration, the input stage can control two switch electrodes and four absorption electrodes with two voltages, and the number of control electrodes can be reduced. In this example, only SW1 of SW1 and SW2 is used as the input port, but when using the input port B, the switch electrode 1 of SW1 is connected to the absorption electrode 10a, and the switch electrode 1 of SW2 is connected to the absorption electrode 10b. For example, the same operation is possible.

FIG. 3 shows a third embodiment of the present invention, which is the second embodiment.
In the embodiment, the output-stage optical switch units SW3 and SW4
FIG. 7 is a plan view showing an optical switch corresponding to the case where the number of output ports is limited to one. The example in the figure is a case where the output ports C of SW3 and SW4 are used as the output ports.
Also in this structure, the structure of the absorption electrode is the same as the structure described above, and the structure in which the switching voltage and the light absorption voltage are substantially the same is used. By the wirings 14 and 15, the switch electrode 1 of SW3 is connected to the absorption electrodes 11a and 10b, and the switch electrode 1 of SW4 is connected to the absorption electrodes 10a and 11b. S
When the output from W1 is output from SW3 and the output from SW2 is output from SW4, a voltage is applied to the absorption electrodes 11a and 10b to absorb the crosstalk light and a voltage is applied to the switch electrode 1 of SW3. This puts the switch in the bar state, and the output of SW1 can be output from SW3. On the other hand, the output of SW2 is output from SW4 in the cross state because no voltage is applied to the switch electrode of SW4. Similarly, when the output of SW1 is output to SW4 and the output of SW2 is output to SW3, a voltage may be applied to the switch electrode 1 of SW4 and the absorption electrodes 10a and 11b. In this configuration as well, the two switch electrodes of the output stage and the four absorption electrodes arranged on the input side can be controlled by two voltages, as described above.

FIG. 4 shows a fourth embodiment of the present invention, which is 4 ×.
FIG. 4 is a plan view showing an optical switch having a non-block configuration of No. 4. This configuration is a combination of the optical switches shown in FIG. For example, in the first and second stages, SW1, SW2, SW5, and SW7 constitute the optical switch of FIG. 1, and SW3
And SW4, SW6, and SW8 constitute another one (however, the input port of the first stage is only the input port A to simplify the configuration). The absorption electrode is SW1
10a of SW1 and 11b of SW2, and 11a of SW1 and SW
2b and 10b are electrically connected by wirings 12a and 13a, and 10c of SW3 and 11d of SW4 are electrically connected to SW3.
11c of No. 4 and 10d of SW4 are connected to wirings 12b and 13b.
Are connected with. Similarly, in the second and third stages, SW5
, SW6, SW9, SW10, SW7, SW8, S
Each of W11 and SW12 constitutes a unit optical switch having the configuration shown in FIG. 1, and SW9, SW11 and SW1 are provided at the third and fourth stages.
3 and SW14, SW10, SW12, SW15 and S
Each unit optical switch having the configuration shown in FIG. 1 is realized by W16 (however, the fourth-stage optical switch unit has one output to simplify the configuration). The connection of the absorption electrode is the first step, 2
Connection is made as shown in FIG.

In this configuration, the number of electrodes is 16 switch electrodes.
The total number of the absorbing electrodes is 12, and the total number of absorbing electrodes is 12, which is 28, and the number of absorbing electrodes can be reduced to half as compared with the conventional example shown in FIG. N ×
In the N optical switch, the number of control electrodes is N · (2N−1) (switch electrode N ² and absorption electrode N · (N−1)), which is N · (N−1) in comparison with the conventional example. The number of electrodes can be reduced.

FIG. 5 shows the fifth embodiment of the present invention and the fourth embodiment.
2 corresponding to the input stage and the configuration of FIG. 3 described above to the output stage in the embodiment of FIG.
FIG. 3 is a plan view showing an optical switch having a non-block configuration.
That is, the configuration of the optical switch of this embodiment corresponds to a combination of the optical switch shown in FIG. 2, the optical switch shown in FIG. 1, and the optical switch shown in FIG.

For example, the first and second stages are SW1 and SW2.
And SW5 and SW7 form a unit optical switch having the same structure as that of FIG. 2, and SW3, SW4, SW6, and SW8 form another unit (however, the input port of the first stage is formed). Only the input port A to simplify). That is, the absorption electrode electrically connects SW1 10a and SW2 11b, and electrically connects SW1 11a and SW2 10b by wirings 12a and 13a, respectively.
10c of W3 and 11d of SW4 are connected to 11c of SW3 and 10d of SW4 by wirings 12b and 13b, respectively. SW1, SW by wiring 14a, 14b
The three switch electrodes 1 and 1 are connected to the absorption electrodes 11a and 10b of SW1 and SW2 and the absorption electrodes 11c and 10d of SW3 and SW4, respectively. The switch electrodes 1 and 1 of SW2 and SW4 are electrically connected to the absorption electrodes 10a and 11b of SW1 and SW2 and the absorption electrodes 10c and 11d of SW3 and SW4 by wirings 15a and 15b, respectively.

The second and third stages are SW5, SW6 and SW9.
And SW10, SW7, SW8, SW11 and SW12
1 and 2 each constitute a unit optical switch having the same structure as that of FIG. That is, the absorption electrode is SW5 10a and S
11b of W6 is electrically connected to 11a of SW5 and 10b of SW6 by wirings 12a and 13a, respectively.
Further, 10c of SW7 and 11d of SW8 are electrically connected to 11c of SW7 and 10d of SW8 by wirings 12b and 13b, respectively.

The third and fourth stages are SW9, SW11 and SW.
13 and SW14, SW10, SW12, SW15, and SW16 constitute a unit optical switch having the same structure as that of FIG. 3 (however, the fourth-stage optical switch unit has one output to simplify the structure. ). That is, the absorption electrodes are 10a of SW13 and 11b of SW14
11a of 13 and 10b of SW14 are wired 12 respectively.
a and 13a electrically connected to each other, and SW15 10
c and 11d of SW16, 11c of SW15 and SW1
6 and 10d are electrically connected by wirings 12b and 13b, respectively. Furthermore, the switch electrodes 1 of SW13 and SW15 are switched to SW by wirings 14a and 14b, respectively.
1, absorption electrodes 11a and 10b of SW2 and SW3 and S
It is connected to the absorption electrodes 11c and 10d of W4. Further, the switch electrodes 1 and 1 of SW14 and SW16 are connected to the absorption electrodes 10 of SW13 and SW14 by the wirings 15a and 15b.
a, 11b and absorption electrodes 10 of SW15, SW16
c and 11d are electrically connected respectively.

Since the switch electrodes of the first and fourth stages are connected to the absorption electrodes, there are 20 control electrodes in total (8 switch electrodes, 4 absorption electrodes, 8 switch electrodes & 8 absorption electrodes).
Therefore, half the number of control electrodes as in the conventional example can be used.

Assuming that this power is N, in the N × N configuration, N · (2N−3) (switch electrodes N · (N−
2), absorption electrode N · (N−3), switch electrode & absorption electrode 2N), and it is possible to reduce N · (N + 1) control electrodes from the conventional example.

FIG. 6 shows the relationship between the number of reduced control electrodes of the N × N optical switch according to the present invention (relative to the conventional example) and the optical switch scale N. With the configuration of the present invention, the number of control electrodes can be significantly reduced in a large-scale optical switch (for example, the reduction number is 200 or more in 16 × 16).

In the above description, the case where the N × N optical switch is integrated on the same chip has been shown. For example, the N × N optical switch is formed by using the 4 × 4 optical switch integrated on the same chip. It is clear that the present invention can be used in any case.

[0034]

As described above, according to the present invention,
Since it is possible to operate the optical switch with the same control by connecting the absorption electrode of the light absorption section to another absorption electrode or the switch electrode of the input / output stage, the number of control electrodes and the number of input pins (input pad (Size), the structure of the optical switch can be simplified, the chip size can be reduced, and the chip yield from one wafer can be improved. Further, the operation control can be simplified and the drive circuit can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view of an optical switch for explaining a first embodiment of the present invention.

FIG. 2 is a plan view of an optical switch for explaining a second embodiment of the present invention.

FIG. 3 is a plan view of an optical switch for explaining a third embodiment of the present invention.

FIG. 4 is a 4 × 4 diagram for explaining a fourth embodiment of the present invention.
3 is a plan view of the optical switch having the non-block configuration of FIG.

FIG. 5: 4 × 4 for explaining a fifth embodiment of the present invention
3 is a plan view of the optical switch having the non-block configuration of FIG.

FIG. 6 is a diagram showing the relationship between the number of reduced electrodes and the scale of a switch according to the present invention.

FIG. 7 is a perspective view of a conventional directional coupling type optical switch having a crosstalk suppressing function.

FIG. 8 is a diagram showing a relationship between a wavelength and a light absorption coefficient for explaining the operation principle of a conventional example.

FIG. 9 is a plan view illustrating a conventional 4 × 4 non-block optical switch.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Switch electrode 2 p ⁺ -InGaAs cap layer 3 p-InP clad layer 4 i-InP clad layer 5 i-MQW layer 6 n-InP substrate 7 n side electrode 9 Separation groove 10a, 10b, 10c, 10d, 11, 11a. , 11
b, 11c, 11d absorption electrodes SW1 to SW16 optical switch section A first optical input port B second optical input port C first optical output port D second optical output port I optical input section II optical switch section III Light output part IV Light absorption part

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsuaki Yanagibashi 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Yuji Hasumi 1-16-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Hiroaki Takeuchi 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Masaki Shintoku 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corp. (72) Inventor Naoya Watanabe 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp.

Claims (4)

[Claims] 1. An optical switch unit comprising two optical waveguides, wherein the optical switch unit switches the optical path of the guided light by controlling the propagation state of the guided light propagating through the two optical waveguides. And the second optical switch section includes at least one input optical waveguide and two output optical waveguides, and the third and fourth optical switch sections include two input optical waveguides and at least one output optical waveguide. An optical waveguide, wherein one of the output optical waveguides of the first optical switch unit is a first optical waveguide.
Connected to one of the input optical waveguides of the third optical switch section via the optical absorption section of the second optical switch section, and the other of the output optical waveguides of the first optical switch section is connected to the second optical waveguide section of the second optical switch section.
Is connected to one of the input optical waveguides of the fourth optical switch section via the optical absorption section of the second optical switch section, and one of the output optical waveguides of the second optical switch section is connected to the third optical waveguide section of the third optical switch section.
Is connected to the other of the input optical waveguides of the third optical switch section via the optical absorption section of the third optical switch section, and the other of the output optical waveguides of the second optical switch section is the fourth optical path.
In the optical switch connected to the other of the input optical waveguides of the fourth optical switch section via the second optical absorption section, the first optical absorption section and the fourth optical absorption section simultaneously emit light. An optical switch comprising: control means for controlling so as to absorb the light; and control means for controlling so that the second light absorbing portion and the third light absorbing portion simultaneously absorb light. 2. The switching control of the first optical switch section,
Means for interlocking control of one of the two light absorbing sections, switching control of the second optical switch section, and interlocking of control of the other of the two light absorbing sections. The optical switch according to claim 1, further comprising: 3. A switching control of the third optical switch section,
Means for interlocking control of one of the two light absorbing sections, switching control of the fourth optical switch section, and interlocking of control of the other of the two light absorbing sections. The optical switch according to claim 1, further comprising: 4. An optical switch comprising a combination of optical switches of any one type or a plurality of types of the optical switches according to claim 1 or 3 in a matrix so as to have a non-blocking configuration.