WO2013111562A1 - Optical circuit, aligning system, and optical circuit aligning method - Google Patents

Abstract

A component to be connected (22) is brought close to a predetermined end portion (25a) of a substrate (25) of an optical circuit (21) that is provided with a switch (26), which connects a first port (26a) to a second port (26b), and a fourth port (26d) to a third port (26c) in a first state. In the first state, optical signals are inputted to an output waveguide (28b) that extends from the third port (26c), intensity of optical signals outputted from an aligning waveguide (29) is measured, said aligning waveguide extending from the fourth port (26d) to an end portion (25c) other than the end portion (25a), and a position where the intensity of the optical signals thus measured is maximum is set as an aligning position.

Description

Optical circuit, alignment system, and alignment method for optical circuit

The present invention relates to an optical circuit, an alignment system, and an optical circuit alignment method used in an optical communication system and an inter-device optical connection system.

In an optical fiber communication system, wavelength division multiplexing (WDM) technology has become widespread. When the WDM technology is applied, various optical circuits including an optical switch are used to realize flexible wavelength path setting.

In connection between an optical circuit and a connected component, a plurality of optical fibers arranged on the same end surface of the connected component may be connected to an input side optical fiber and an output side optical fiber of the optical circuit, respectively. In this case, the input side optical fiber and the output side optical fiber of the optical circuit are disposed on the same end face of the optical circuit.

Here, for example, Patent Documents 1 to 3 disclose alignment methods in the case where an input side optical fiber and an output side optical fiber of an optical circuit are connected to a plurality of optical fibers of connected parts on the same end face. .

In Patent Document 1, an aligning optical waveguide extending to the opposite end face is disposed at a position shifted by 125 μm from the input side optical fiber and the output side optical fiber of the optical circuit, and connected using the aligning optical waveguide. A technique is disclosed in which after aligning with a component, the optical circuit is moved by 125 μm to be bonded and fixed to the connected component.

In Patent Document 2, two of the input / output optical waveguides of the optical circuit are extended to another end face to form an alignment optical waveguide, and two alignment optical fibers are added to the connected parts. A technique for aligning using a centering optical waveguide and a centering optical fiber is disclosed.

Patent Document 3 discloses a technique for providing an optical waveguide that guides light having a specific wavelength passing through an arrayed waveguide diffraction grating to another end face, and performing an alignment operation of the optical fiber array using the optical waveguide. Yes.

JP 2004-004907 A JP-A-10-227936 JP 2000-292636 A

However, in the technique of Patent Document 1, after aligning the optical fiber of the connected component and the aligning optical waveguide, the optical circuit is moved and bonded and fixed to the connected component. The relative position between the connected component and the optical circuit may be shifted from the optimum position due to the movement, and the connection accuracy is lowered. Furthermore, it is necessary to provide equipment for moving the optical circuit with high accuracy.

In addition, the technique of Patent Document 2 requires that the number of optical fibers of the connected parts be prepared in excess of the originally required number, thereby reducing the versatility of the optical circuit.

Furthermore, the technique of Patent Document 3 needs to use light of a specific wavelength for alignment, and it is necessary to separately arrange a light source for alignment.

An object of the present invention is to connect an optical circuit and a connected device without providing a dedicated configuration for the measuring system and the connected component when the input / output side waveguide is connected to the same connected component on the predetermined end face side. It is an object to provide an optical circuit, an alignment system, and an optical circuit alignment method capable of aligning with a component.

In order to achieve the above object, an optical circuit according to the present invention includes a substrate, and in the first state, the first port is connected to the second port, the fourth port is connected to the third port, and in the second state. Includes a switch connecting the first port to the third port and the fourth port to the second port, an input waveguide extending from the first port to a predetermined end of the substrate, and a predetermined end from the second and third ports And two output waveguides each extending up to 4 mm, and an adjustment waveguide extending from the fourth port to an end other than the predetermined end of the substrate.

In order to achieve the above object, an alignment system according to the present invention includes the above-described optical circuit, a connected component having an optical fiber connected to each of an input waveguide and an output waveguide of the optical circuit, and an adjustment guide. Measuring means for measuring the intensity of the optical signal for adjustment emitted from the optical waveguide for adjustment arranged at the opposite position of the waveguide, and the relative position of the optical circuit and the connected component so that the measured intensity is maximized And control means for controlling. At the time of alignment between the optical circuit and the connected component, the switch is set to the first state, and the connected component outputs an alignment optical signal to the output waveguide extending from the third port.

To achieve the above object, the optical circuit alignment method according to the present invention is such that, in the first state, the first port is connected to the second port, the fourth port is connected to the third port, and the second state In this case, the connected component is brought close to a predetermined end of the substrate of the optical circuit having a switch for connecting the first port to the third port and the fourth port to the second port. The optical signal is input from the output waveguide extending from the port, and the intensity of the optical signal output from the adjustment waveguide extending from the fourth port to the end other than the predetermined end of the substrate is measured. The position that becomes is the alignment position.

The optical circuit, the alignment system, and the alignment method of the optical circuit according to the present invention align the measurement system and the connected component when the input / output side waveguide is connected to the same connected component on the predetermined end face side. The alignment between the optical circuit and the connected component can be performed without providing a dedicated configuration.

1 is a configuration diagram of an optical circuit 10 according to a first embodiment of the present invention. It is a lineblock diagram of alignment system 20 concerning a 1st embodiment of the present invention. 1 is a configuration diagram of an optical circuit 30 according to a first embodiment of the present invention. It is a block diagram of the optical circuit 40 which concerns on the modification of the 1st Embodiment of this invention. It is a block diagram of the optical circuit 50 which concerns on the modification of the 1st Embodiment of this invention. It is a block diagram of the optical circuit 60 which concerns on another modification of the 1st Embodiment of this invention. It is a block diagram of the optical circuit 70 which concerns on another modification of the 1st Embodiment of this invention. It is a block diagram of the optical circuit 80 which concerns on another modification of the 1st Embodiment of this invention. It is a block diagram of the state in which the optical circuit 100 which concerns on the 2nd Embodiment of this invention is connected with the optical fiber array. It is a perspective view of the optical switch element 110a which concerns on the 2nd Embodiment of this invention. It is a block diagram of the state in which the optical circuit 300 which concerns on the modification of the 2nd Embodiment of this invention is connected with the optical fiber array 400. It is a block diagram of the state in which the optical circuit 500 which concerns on the 3rd Embodiment of this invention is connected with the optical fiber array 600.

(First embodiment)
An optical circuit according to the first embodiment of the present invention will be described. FIG. 1A shows a configuration diagram of an optical circuit according to the present embodiment. 1A, an optical circuit 10 according to the present embodiment includes a substrate 11, a switch 12, an input waveguide 13, two output waveguides 14a and 14b, and an adjustment waveguide 15.

On the substrate 11, a switch 12, an input waveguide 13, two output waveguides 14a and 14b, and an adjustment waveguide 15 are arranged. The input waveguide 13 and the two output waveguides 14 a and 14 b extend from the switch 12 to the same end 11 a of the substrate 11.

The switch 12 includes four ports 12a to 12d and two optical paths (not shown), and a switch driving unit (not shown) is arranged in the vicinity of one of the optical paths, and voltage application, carrier injection, or heat source input is performed on the switch driving unit. Thus, the optical path is switched. Here, a state in which voltage application, carrier injection, or heat source input is not performed on the switch drive unit is a first state, and a state in which voltage application is performed on the switch drive unit is a second state. Note that a predetermined threshold value is set, and a state where the applied voltage value or the like is smaller than the threshold value may be the first state, and a state larger than the threshold value may be the second state. As the switch 12, for example, a Mach-Zehnder type element can be applied.
The switch 12 according to the present embodiment connects the first port 12a to the second port 12b and the fourth port 12d to the third port 12c in the first state, and the first port in the second state. 12a is connected to the third port 12c, and the fourth port 12d is connected to the second port 12b. The switch 12 is set to the first state at the time of alignment work with a connected part (not shown). By performing the alignment operation in the first state in which no voltage is applied to the switch drive unit, the alignment operation can be performed efficiently.

The input waveguide 13 extends from the first port 12a of the switch 12 to the end 11a of the substrate 11, and emits an optical signal incident from a connected component (not shown) to the first port 12a of the switch 12.

The output waveguides 14a and 14b extend from the second and third ports 12b and 12c of the switch 12 to the end 11a of the substrate 11, respectively. When the output waveguide 14a is in the first state, the output waveguide 14a emits an optical signal incident from a connected component (not shown) via the switch 12 to the connected component. On the other hand, in the second state, the output waveguide 14b emits an optical signal incident from the connected component via the switch 12 to the connected component. Further, the output waveguide 14b emits an optical signal incident from the connected component to the switch 12 during the alignment operation with the connected component.

The adjustment waveguide 15 extends from the fourth port 12d of the switch 12 to the end portion 11b facing the end portion 11a of the substrate 11, and exits from the connected component via the switch 12 during alignment with the connected component. The optical signal thus emitted is emitted from the end 11 b side of the substrate 11.

The alignment system including the optical circuit configured as described above will be described. The block diagram of the alignment system which concerns on this embodiment is shown to FIG. 1B. In FIG. 1B, the alignment system 20 includes an optical circuit 21, a connected component 22, a measurement unit 23, and a control unit 24.

In FIG. 1B, the connected component 22 is disposed on the end 25 a side of the substrate 25 of the optical circuit 21, and the measuring means 23 is disposed at a position facing the adjustment waveguide 29 on the end 25 c side of the substrate 25. . The control means 24 is disposed below the connected component 22 and positions the connected component 22 in the up / down / left / right direction and the rotation direction.

In the alignment system 20 according to this embodiment, when performing alignment work between the optical circuit 21 and the connected component 22, first, the optical circuit 21 is set to the first state. Thereafter, the connected component 22 is brought into contact with the end 25a of the optical circuit 21, and the input waveguide 27 and the output waveguides 28a and 28b of the optical circuit 21 and the optical fibers 22a to 22c of the connected component 22 are coupled. Let In this state, an alignment optical signal is emitted from the optical fiber 22 b of the connected component 22 to the output waveguide 28 b of the optical circuit 21.

The alignment optical signal incident on the output waveguide 28b is emitted from the end 25c side of the substrate 25 to the outside through the third port 26c, the fourth port 26d, and the adjustment waveguide 29 of the switch 26. . The measuring means 23 measures the intensity of the alignment optical signal emitted from the adjustment waveguide 29 at the end 25 c of the substrate 25 and outputs the measurement result to the control means 24.

The control unit 24 adjusts the relative position between the optical circuit 21 and the connected component 22 based on the measurement result input from the measurement unit 23. In the present embodiment, the control unit 24 adjusts the position of the connected component 22 in the up / down / left / right direction and the rotation direction so that the measurement result input from the measurement unit 23 becomes the maximum value. Then, the optical circuit 21 and the connected component 22 are bonded and fixed at the position where the measurement result becomes the maximum value. The end face on the end 25c side of the adjustment waveguide 29 is processed so that unnecessary optical signals do not enter from the adjustment waveguide 29 of the optical circuit 21 after the optical circuit 21 and the connected component 22 are bonded and fixed. It is desirable to do.

In the optical circuit 21 and the connected component 22 that have been aligned, an optical signal enters the input waveguide 27 of the optical circuit 21 from the optical fiber 22c of the connected component 22 during normal operation. The optical signal that has entered the input waveguide 27 is output to either the output waveguide 28 a or 28 b depending on the state of the switch 21, and enters one of the optical fibers 22 a and 22 b of the connected component 22.

As described above, when the optical circuit 10 and the alignment system 20 according to the present embodiment connect the input waveguide and the output waveguide of the optical circuit on the same end surface side as the connected component, Alignment of the optical circuit and the connected component can be performed without providing a dedicated configuration for the connecting component.

That is, in the optical circuit 10 and the alignment system 20 according to the present embodiment, the adjustment waveguide is extended to an end different from the end where the connected component is arranged, so that the optical circuit and Connected parts can be bonded and fixed. In addition, since the optical fiber used during normal operation is used for alignment work, it is not necessary to arrange the optical fiber for alignment work in the connected parts, and it has a special wavelength as an optical signal for adjustment There is no need to use an optical signal.

Here, a plurality of the optical circuits described above can be combined. For example, FIG. 1C shows a configuration diagram of an optical circuit in which two optical circuits described above are combined. 1C, the optical circuit 30 includes a substrate 31, switches 32a and 32b, input waveguides 33a and 33b, output waveguides 34a to 34d, and adjustment waveguides 35a and 35b.

When aligning the above-described optical circuit 30 at the connected part (not shown) and the end face 31a, after setting the switches 32a and 32b to the first state, the aligning optical signal is incident from the output waveguides 34b and 34c. . The adjustment optical signals incident from the output waveguides 34b and 34c are emitted to the adjustment waveguides 35a and 35b through the switches 32a and 32b, respectively, and are emitted from the end portion 31b side of the substrate. Then, the intensity of the optical signal emitted from the adjustment waveguides 35a and 35b is measured by a measuring device (not shown) arranged on the end 31b side, and the optical circuit 30 is adjusted so that the intensity of the adjustment optical signal is maximized. Align.

In the aligned optical circuit 30, an optical signal enters the input waveguides 33a and 33b from a connected component (not shown) during normal operation. The optical signal that has entered the input waveguides 33a and 33b is incident on the switches 32a and 32b, and either one of the output waveguides 34a and 34b or the output waveguides 34c and 34d depending on the state of the switches 32a and 32b. The light is emitted to either one and enters an optical fiber of a connected component (not shown).

(Modification of the first embodiment)
A modification of the first embodiment will be described. First, as a first modification of the first embodiment, in the optical circuit 10 of FIG. 1A described in the first embodiment, a second switch is disposed at each stage subsequent to the output waveguides 14a and 14b. Will be described. FIG. 2A shows a configuration diagram of an optical circuit in which a second switch is disposed in the subsequent stage of the output waveguides 14a and 14b.

2A includes a substrate 41, a first switch 42, second switches 43a and 43b, an input waveguide 44, output waveguides 45a to 45d, connection waveguides 46a and 46b, and an adjustment waveguide 47. Is provided. The first switch 42 is configured in the same manner as the switch 10 shown in FIG. 1A. The second switches 43 a and 43 b are formed by terminating the fourth port 12 d of the switch 10. The connection waveguides 46a and 46b connect the first switch 42 and the second switches 43a and 43b, respectively.

When aligning the optical circuit 40 with a connected component (not shown), the first switch 42 and the second switches 43a and 43b are set to the first state, and then an optical signal for alignment is sent to the output waveguide 45d. Exit. Then, the adjustment optical signal incident on the output waveguide 45d is incident on the second switch 43b, and is emitted to the connection waveguide 46b because the second switch 43b is set to the first state. Is done.

The adjustment optical signal incident on the connection waveguide 46 b is emitted from the first switch 42 toward the adjustment waveguide 47, and is emitted from the end 41 b of the substrate 41. Then, the intensity of the adjustment optical signal emitted from the adjustment waveguide 47 is measured on the end 41b side, and the optical circuit 40 and the connected component are bonded and fixed at a position where the intensity becomes maximum.

Therefore, the optical circuit 40 according to the present embodiment aligns the measurement system and the connected component when the input waveguide and the output waveguide of the optical circuit 40 are connected on the same end face side as the connected component (not shown). The alignment of the optical circuit 40 and the connected component can be performed without providing a dedicated configuration.

In the aligned optical circuit 40, an optical signal enters the input waveguide 44 of the optical circuit 40 from an optical fiber of a connected component (not shown) during normal operation. The optical signal that has entered the input waveguide 44 enters the first switch 42, is output to one of the connection waveguides 46a and 46b depending on the state of the first switch 42, and the second switch 43a, It is incident on either of 43b. Further, the optical signal incident on either of the second switches 43a and 43b is emitted to one of the output waveguides 45a to 45d in accordance with the state of the second switches 43a and 43b, and is connected to a not-shown component. Is incident on the optical fiber.

Here, in the optical circuit 40 described above, the fourth ports of the second switches 43a and 43b are terminated. Instead of terminating, the fourth ports of the second switches 43a and 43b are connected to other than the end portion 41a. An adjustment waveguide extending to the end can also be added. An example of the added adjustment waveguides 47a and 47b is shown by a dotted line in FIG. 2A. When alignment is performed using the added adjustment waveguides 47 a and 47 b, adjustment optical signals are incident from the output waveguides 45 b and 45 c of the optical circuit 40. By performing alignment using the adjustment optical signals emitted from the three adjustment waveguides 47, 47a, and 47b, variations in coupling efficiency are reduced, and alignment with higher accuracy can be performed.

Here, a third switch may be further arranged in the subsequent stage of the output waveguides 45a to 45d of the optical circuit 40 described above. FIG. 2B shows a configuration diagram of the optical circuit 50 when the optical switches are arranged in three stages. An example of the adjustment waveguides 59a to 59d that can be added is shown by a dotted line in FIG. 2B. Detailed operation of the optical circuit 50 shown in FIG. 2B will be described in detail in the second embodiment.

Next, as a second modification of the first embodiment, a case will be described in which the second switch is arranged before the input waveguide 13 in the optical circuit 10 of FIG. 1A described in the first embodiment. . FIG. 3A shows a configuration diagram of an optical circuit in which a second switch is arranged in front of the input waveguide 13. The optical circuit 60 in FIG. 3A has a configuration in which a second optical switch 63 is added before the input waveguides 33a and 33b of the optical circuit 30 in FIG. 1C.

3A, an optical circuit 60 according to this embodiment includes a substrate 61, first switches 62a and 62b, a second switch 63, an input waveguide 64, output waveguides 65a to 65d, and connection waveguides 66a and 66b. And adjustment waveguides 67a and 67b.

When aligning the optical circuit 60 with a connected part (not shown), the first switches 62a and 62b and the second switch 63 are set to the first state, and then are aligned from the output waveguides 65b and 65c, respectively. An optical signal is incident. The adjustment optical signal incident from the output waveguide 65b is incident on the first switch 62a, and is emitted to the adjustment waveguide 67a side because the first switch 62a is set to the first state. The On the other hand, the adjustment optical signal incident from the output waveguide 65b is emitted to the adjustment waveguide 67b side.

Then, the intensity of the adjustment optical signal emitted from the adjustment waveguides 67a and 67b is measured by a measuring unit (not shown), and the total intensity of the adjustment optical signals emitted from the adjustment waveguides 67a and 67b is measured. The optical circuit 60 is positioned so that is maximized.

Therefore, it is possible to align the optical circuit 60 and the connected component without providing a dedicated configuration for the measuring system and the connected component, and the optical circuit 60 and the connected component are connected to the predetermined end surface 61a side of the substrate 61. can do.

In the aligned optical circuit 60, an optical signal enters the input waveguide 64 of the optical circuit 60 from the optical fiber of the connected component during normal operation. Then, the optical signal incident on the input waveguide 64 is incident on the second switch 63 and is emitted to either the connection waveguide 66a or 66b depending on the state of the second switch 63. Incident on either 62a or 62b. The optical signal incident on either of the first switches 62a and 62b is emitted to one of the output waveguides 65a to 65d in accordance with the state of the first switches 62a and 62b, and enters the optical fiber of the connected component. Incident.

Also, two optical circuits 60 described above can be combined. FIG. 3B shows a configuration diagram of the optical circuit 70 in which two optical circuits 60 are combined and the first switches 72a to 72d are nested. 3B, an optical circuit 70 according to the present embodiment includes a substrate 71, first switches 72a to 72d, second switches 73a and 73b, input waveguides 74a and 74b, output waveguides 75a to 75h, and connection guides. Waveguides 76a to 76d and adjustment waveguides 77a and 77b are provided.

When aligning the optical circuit 70 with a connected component (not shown), the first switches 72a to 72d and the second switches 73a and 73b are set to the first state, and then aligned to the output waveguides 75b and 75g, respectively. An optical signal for use is emitted. The adjustment optical signal incident on the output waveguide 75b is emitted from the end 71b via the first switch 72a and the adjustment waveguide 77a. On the other hand, the adjustment optical signal incident on the output waveguide 75g is emitted from the end portion 71b via the first switch 72d and the adjustment waveguide 77b. Then, the optical circuit 70 is positioned so that the total intensity of the adjustment optical signals emitted from the adjustment waveguides 77a and 77b is maximized.

Therefore, in the optical circuit 70 in which the input waveguides 74a and 74b and the output waveguides 75a to 75h are arranged on the predetermined end surface 71a side of the substrate 71, the optical system 70 is not provided with a configuration dedicated for alignment in the measurement system or the connected component. Alignment between the circuit 70 and a connected component (not shown) can be performed.

Here, an example of the adjustment waveguides 77c and 77d that can be added is shown by a dotted line in FIG. 3B. When the alignment work is performed using the added adjustment waveguides 77 c and 77 d, the adjustment optical signal is incident from the output waveguides 75 d and 75 e of the optical circuit 70.

In the aligned optical circuit 70, an optical signal enters the input waveguides 74a and 74b of the optical circuit 70 from the optical fiber of the connected component during normal operation. The optical signal incident on the input waveguide 74a enters the second switch 73a, and is output to either the connection waveguide 76a or 76b depending on the state of the second switch 73a. It is incident on either one of 72c. Then, an optical signal that has entered one of the first switches 72a and 72c enters one of the output waveguides 75a, 75b, 75e, and 75f depending on the state of the switch, and is emitted to the optical fiber of the connected component. Is done. Similarly, the optical signal incident on the input waveguide 74b enters one of the output waveguides 75c, 75d, 75g, and 75h, and is emitted to the optical fiber of the connected component.

Here, it is also possible to arrange an optical splitter downstream of the output waveguides 75a to 75h of the optical circuit 70 described above, and to switch the optical signal incident from the input waveguides 74a and 74b at the output end. FIG. 3C shows a configuration diagram of an optical circuit in the case where an optical splitter is arranged at the subsequent stage of the output waveguides 75a to 75h.

3C, an optical circuit 80 according to the present embodiment includes a substrate 81, first switches 82a to 82d, second switches 83a and 83b, input waveguides 84a and 84b, connection waveguides 85a to 85h, and 86a to 86a. 86d, adjustment waveguides 87a and 87b, optical splitters 88a to 88d, and output waveguides 89a to 89d. An example of the adjustment waveguides 87c and 87d that can be added is indicated by a dotted line in FIG. 3C.

Each of the optical splitters 88a to 88d includes two input ports and one output port. The optical splitters 88a to 88d select one of the two input ports and emit an optical signal incident from the selected input port to the output port. Then, the optical signal emitted from the output port is emitted from the output waveguides 89a to 89d to the end portion 81a side. In the optical splitters 88a to 88d according to the present embodiment, the two input ports operate in conjunction with each other. For example, when the optical splitter 88a selects the first input port, the other optical splitters 88b to 88d also select the first input port. By alternately switching the input ports of the optical splitters 88a to 88d, optical signals incident from the input waveguides 84a and 84b can be alternately emitted from the output waveguides 89a to 89d. Detailed operation of the optical circuit including the optical splitter will be described in a third embodiment.

(Second Embodiment)
A second embodiment will be described. In this embodiment, a 1 × 8 optical switch is applied as the optical circuit. FIG. 4 shows a configuration diagram in a state where the optical circuit according to the present embodiment is connected to the optical fiber array.

The optical circuit 100 according to this embodiment includes seven optical switch elements 110a to 110d, 120a, 120b, and 130, an input optical waveguide 140, eight output optical waveguides 150a to 150h, and two alignment optical waveguides 160. , 170 and six connection optical waveguides 180a to 180f for connecting the optical switch elements. Each optical waveguide has a core made of silicon and a clad made of quartz. The optical fiber array 200 includes a fixing glass block 210 and nine optical fibers 220a to 220i.

In FIG. 4, an optical fiber array 200 is disposed on the end face 101 side of the optical circuit 100, the output optical waveguides 150 a to 150 h and the input optical waveguide 140 of the optical circuit 100, and the nine optical fibers 220 a to 220 i of the optical fiber array 200. Are connected via a fixing glass block 210.

In the optical circuit 100, the input optical waveguide 140 and the eight output optical waveguides 150a to 150h extend toward the end face 101 where the optical fiber array 200 is disposed. On the other hand, the two aligning optical waveguides 160 and 170 extend to the end surface 102 side opposite to the end surface 101 where the optical fiber array 200 is not disposed.

In the optical switch elements 110a to 110d, 120a, 120b, and 130, the emission direction of the optical signal is switched according to the driving state. As the optical switch elements 110a to 110d, 120a, 120b, and 130, Mach-Zehnder type elements that change the light intensity using interference between two optical paths can be applied. In the present embodiment, the optical switch elements 110a to 110d, 120a, 120b, and 130 are driven by being heated using a heater.

The optical switch element 110a will be described in detail. A perspective view of the optical switch element 110a is shown in FIG. The optical switch element 110a forms an optical waveguide by forming a core 112a using silicon and a clad 113a using quartz on a silicon substrate 111a. In the optical switch element 110a, two input ports 114a and 115a are formed at one of a pair of opposing ends, and two output ports 116a and 117a are formed at the other end. In the optical switch element 110a according to the present embodiment, the input port 114a is connected to the output optical waveguide 150b in FIG. 4, the input port 115a is connected to the output optical waveguide 150a, the output port 116a is connected to the connection optical waveguide 180a, and the output port 117a is connected. Each is connected to the aligning optical waveguide 160. When an optical signal is input from the input port 114a, the input optical signal is joined again via the two arms of Mach-Zehnder and interferes at the output ports 116a and 117a. Also, a pair of electrode pairs 118a is disposed above one arm of the optical switch element 110a, and a heater 119a is disposed between the electrode pairs 118a.

By applying a voltage to the electrode pair 118a of the optical switch element 110a, a current flows through the heater 119a and the heater 119a generates heat. When the heater 119a generates heat and the optical waveguide directly below is maintained at a predetermined temperature, the refractive index of the core 112a changes, and the optical path lengths of both arms are shifted by a half wavelength. Therefore, the optical signal input from the input port 114a and passing through the two arms has a phase difference of 0 at the output port 116a, and the optical signals of each other are strengthened. On the other hand, the optical signal input from the input port 114a and passing through the two arms has a phase difference of π at the output port 117a, and the optical signals cancel each other. That is, when a predetermined voltage is applied to the electrode pair 118a, the optical signal input from the input port 114a is output to the output port 116a.

On the other hand, when no voltage is applied to the electrode pair 118a of the optical switch element 110a, the optical path lengths of both arms of the optical switch element 110a are equal. Therefore, the optical signal input from the input port 114a and passing through the two arms has a phase difference of π at the output port 116a, and the optical signals cancel each other. On the other hand, the optical signal input from the input port 114a and passing through the two arms has a phase difference of 0 at the output port 117a, and the optical signals of each other are strengthened. That is, when no voltage is applied to the electrode pair 118a, the optical signal input from the input port 114a is output to the output port 117a. The state in which no voltage is applied to the electrode pair 118a corresponds to the first state of the claims, and the state in which voltage is applied to the electrode pair 118a corresponds to the second state.

The optical switch element 130 is also formed in the same manner as the optical switch element 110a. Further, the optical switch element 110a is a 2 × 2 optical switch, but by terminating any one of the four ports 114a, 115a, 116a, and 117a, the 1 × 2 optical switch elements 110b to 110d are terminated. , 120a, 120b can be formed.

Next, the alignment procedure between the optical circuit 100 and the optical fiber array 200 will be described with reference to FIGS. When aligning the output optical waveguides 150a to 150h and the input optical waveguide 140 of the optical circuit 100 and the optical fibers 220a to 220i of the optical fiber array 200, no voltage is applied to each electrode pair of all the optical switch elements. After setting to the state (first state), alignment optical signals are emitted from the optical fibers 220b and 220h of the optical fiber array 200. Then, the optical fiber array 200 is brought close to the end face 101 of the optical circuit 100, and the output optical waveguides 150a to 150h and the input optical waveguide 140 of the optical circuit 100 and the optical fibers 220a to 220i of the optical fiber array 200 are coupled.

When the optical fiber 220b and the optical waveguide 150b are coupled, the alignment optical signal emitted from the optical fiber 220b is input to the optical waveguide 150b and input to the input port 114a of the optical switch element 110a. Since no voltage is applied to the electrode pair of the optical switch element 110a, the alignment optical signal input from the input port 114a is output to the output port 117a and output from the alignment optical waveguide 160 to the outside. The Then, on the end face 102 side, the aligning optical signal intensity output from the aligning optical waveguide 160 is measured using a measuring instrument (not shown).

On the other hand, when the optical fiber 220h and the optical waveguide 150h are coupled, the optical signal for alignment emitted from the optical fiber 220h is input to the optical waveguide 150h and input to the optical switch element 110d. The alignment optical signal input to the optical switch element 110d is output to the connection optical waveguide 180d because no voltage is applied to the electrode pair of the optical switch element 110d, and the optical switch element 120b, the connection optical waveguide 180f, The light is output from the alignment optical waveguide 170 to the outside via the optical switch element 130. Then, on the end face 102 side, the aligning optical signal intensity output from the aligning optical waveguide 170 is measured by a measuring instrument (not shown).

Then, the optical fiber array 200 is bonded and fixed to the optical circuit 100 at a position where the total intensity of the alignment optical signals output from the alignment optical waveguides 160 and 170 is maximized. By performing alignment using the optical signals for adjustment output from the two alignment optical waveguides 160 and 170, variations in coupling efficiency are reduced, and alignment with higher accuracy can be performed.

In the aligned optical circuit 100 and optical fiber array 200, during normal operation, an optical signal is input from the optical fiber 220 i of the optical fiber array 200 to the input optical waveguide 140, and from the input optical waveguide 140 to the optical switch element 130. Emitted. The optical signal incident on the optical switch element 130 is emitted to the optical switch element 120a or the optical switch element 120b side according to the driving state of the optical switch element 130, and the optical switch element 120a, 120b according to the driving state of the optical switch element 120a. The light is emitted to any one of 110a to 110d, and further emitted from any one of the output optical waveguides 150a to 150h according to the driving state of the optical switch elements 110a to 110d. The optical signal emitted from any one of the output optical waveguides 150a to 150h is incident on any one of the optical fibers 220a to 220h.

As described above, the optical circuit 100 and the optical fiber array 200 according to the present embodiment include the output optical waveguides 150a to 150h and the input optical waveguide 140 without providing a configuration dedicated for alignment in the measurement system or the connected component. The optical fibers 220a to 220i can be aligned.

In this embodiment, the aligning optical waveguides 160 and 170 are both drawn out to the end face 102 side facing the optical fiber array 200, but the present invention is not limited to this. The aligning optical waveguides 160 and 170 can be drawn to the upper end surface side or the lower end surface side where the optical fiber array 200 is not disposed. Further, a branch may be provided in the middle of the aligning optical waveguides 160 and 170 and drawn out to a plurality of end faces.

(Modification of the second embodiment)
A modification of the second embodiment will be described. FIG. 6 shows a configuration diagram of the state in which the optical circuit according to the present embodiment is connected to the optical fiber array. The optical circuit 300 shown in FIG. 6 is formed by disposing the optical switches 310a to 310d in the subsequent stage of the output waveguides 65a to 65d in FIG. 3A described in the modification of the first embodiment.

In FIG. 6, an optical circuit 300 according to this embodiment includes seven optical switch elements 310a to 310d, 320a, 320b, 330, an input optical waveguide 340, eight output optical waveguides 350a to 350h, and two alignments. Optical waveguides 360 and 370, and six connection optical waveguides 380a to 380f for connecting the optical switch elements. The optical fiber array 400 includes a fixing glass block 410 and nine optical fibers 420a to 420i. Here, the optical switch elements 310a to 310d, 320a, 320b, and 330 according to this embodiment are the same as the optical switch elements 110a to 110d, 120a, 120b, and 130 of FIGS. 4 and 5 described in the second embodiment. It is configured.

In FIG. 6, an optical fiber array 400 is arranged on one end face 301 side of the optical circuit 300. The input optical waveguide 340 and the eight output optical waveguides 350a to 350h of the optical circuit 300 extend toward the end face 301 on which the optical fiber array 400 is disposed. On the other hand, the two alignment optical waveguides 360 and 370 extend to the end surface 302 side opposite to the end surface 301 where the optical fiber array 400 is not disposed. The output optical waveguides 350 a to 350 h and the input optical waveguide 340 of the optical circuit 300 and the nine optical fibers 420 a to 420 i of the optical fiber array 400 are connected via a fixing glass block 410.

Next, the alignment procedure between the optical circuit 300 and the optical fiber array 400 will be described. When alignment is performed between the output optical waveguides 350a to 350h and the input optical waveguide 340 of the optical circuit 300 and the optical fibers 420a to 420i of the optical fiber array 400, no voltage is applied to the electrode pairs of all the optical switch elements. Thus, alignment optical signals are emitted from the optical fibers 420 b and 420 h of the optical fiber array 400, and the optical fiber array 400 is brought close to the end face 301 of the optical circuit 300.

When the optical fiber 420b and the optical waveguide 350b are coupled, an optical signal for alignment is input to the optical waveguide 350b and input to the optical switch element 310a. Since no voltage is applied to the electrode pair of the optical switch element 310a, the incident alignment optical signal is emitted to the alignment optical waveguide 360, and the intensity is measured on the end face 302 side.

Similarly, the aligning optical signal emitted from the optical fiber 420h is emitted from the aligning optical waveguide 370 to the outside via the optical waveguide 350g, the optical switch element 310d, and the aligning optical waveguide 370, and is end faced. The intensity is measured on the 302 side.

Then, the optical fiber array 400 is bonded and fixed to the optical circuit 300 at a position where the total intensity of the alignment optical signals emitted from the alignment optical waveguides 360 and 370 is maximized. The measurement of the light intensity at the time of alignment may be performed at only one location, but it is desirable to perform the measurement at two locations because the variation in coupling efficiency can be reduced.

In the aligned optical circuit 300 and optical fiber array 400, during normal operation, an optical signal is emitted from the optical fiber 420e of the optical fiber array 400, and the emitted optical signal is transmitted via the input optical waveguide 340. Depending on the driving state of the optical switch element 330, it is emitted to either the optical switch element 320a or the optical switch element 320b, and further depending on the driving state of the optical switch element 330a˜ It is emitted to any one of 310d. An optical signal incident on one of the optical switch elements 310a to 310d is emitted from one of the output optical waveguides 350a to 350h according to the driving state thereof, and is coupled to the optical fibers 420a to 420d of the optical fiber array 400 that is coupled. The light is emitted to any one of 420f to 420i.

As described above, the optical circuit 300 and the optical fiber array 400 according to the present embodiment align the optical circuit 300 and the optical fiber array 400 without providing a dedicated configuration for the measuring system or the connected component. be able to.

In the present embodiment, the aligning optical waveguides 360 and 370 are both drawn to the end face 302 side facing the optical fiber array 400, but the present invention is not limited to this. The aligning optical waveguides 360 and 370 can be drawn to the upper end surface side or the lower end surface side where the optical fiber array 400 is not disposed. Further, a branch may be provided in the middle of the aligning optical waveguides 360 and 370 and drawn out to a plurality of end faces.

(Third embodiment)
A third embodiment will be described. In this embodiment, a 4 × 4 optical switch is applied as the optical circuit. FIG. 7 shows a configuration diagram of the state in which the optical circuit according to the present embodiment is connected to the optical fiber array.

7, the optical circuit 500 according to the present embodiment includes twelve optical switch elements 510a to 510d, 520a to 520d, 530a to 530d, four 1 × 4 optical splitter elements 540a to 540d, and four input optical waveguides. Waveguides 550a to 550d, four output optical waveguides 560a to 560d, two alignment optical waveguides 570 and 580, and a plurality of connection optical waveguides respectively connecting the optical switch element and the optical splitter element are provided. The optical switch elements 510a to 510d, 520a to 520d, and 530a to 530d are configured in the same manner as the optical switch elements shown in FIG. The optical fiber array 600 includes a fixing glass block 610 and eight optical fibers 620a to 620h.

In FIG. 7, an optical fiber array 600 is arranged on one end face 501 side of the optical circuit 500. The input optical waveguides 550a to 550d and the output optical waveguides 560a to 560d of the optical circuit 500 extend to the end face 501 side where the optical fiber array 600 is disposed. On the other hand, the two aligning optical waveguides 570 and 580 extend toward the end face 502 where the optical fiber array 600 is not disposed. In this embodiment, each optical waveguide has a core made of silicon and a clad made of quartz. The input optical waveguides 550a to 550d and the output optical waveguides 560a to 560d of the optical circuit 500 are connected to the eight optical fibers 620a to 620h of the optical fiber array 600.

Each of the optical splitter elements 540a to 540d includes four input ports and one output port. The optical splitter elements 540a to 540d emit optical signals incident from the selected input port from the output port. The optical splitter elements 540a to 540d operate in conjunction with each other after the connection / fixation between the optical circuit 500 and the optical fiber array 600 is completed. For example, when the optical splitter element 540a selects the first input port, the other optical splitter elements 540b to 540d also select the first input port.

Next, the alignment procedure between the optical circuit 500 and the optical fiber array 600 will be described. When aligning the input optical waveguides 550a to 550d and the output optical waveguides 560a to 560d of the optical circuit 500 and the optical fibers 620a to 620h of the optical fiber array 600, voltages are applied to the electrode pairs of all the optical switch elements. The optical fiber 620b, 620g of the optical fiber array 600 is set to a state where no application is performed, and an optical signal for alignment is emitted, and the optical splitter element 540b selects the first input port, and the optical splitter element 540c performs the fourth operation. Select the input port. Then, the optical fiber array 600 is brought close to the end surface 501 of the optical circuit 500, and the input optical waveguides 550a to 550d and the output optical waveguides 560a to 560d of the optical circuit 500 and the optical fibers 620a to 620h of the optical fiber array 600 are coupled. .

When the optical fiber 620b and the optical waveguide 560b are coupled, the aligning optical signal enters the optical waveguide 560b and is input to the optical splitter element 540b. Since the optical splitter element 540b selects the first input port, the alignment optical signal input to the optical splitter element 540b is input to the optical switch element 510a via the first input port. Since no voltage is applied to the electrode pair of the optical switch element 510a, the input alignment optical signal is input to the alignment optical waveguide 570, and the intensity is measured on the end face 502 side.

On the other hand, when the optical fiber 620g and the optical waveguide 560c are coupled, the alignment optical signal is emitted to the outside through the optical waveguide 560c, the optical splitter element 540c, the optical switch element 520d, and the alignment optical waveguide 580. Then, the strength is measured at the end face 502.

The optical fiber array 600 is bonded and fixed to the optical circuit 500 at a position where the total intensity of the aligning optical signals emitted from the aligning optical waveguides 570 and 580 is maximized, and further, the optical splitter element 540a. ˜540d are associated with each other.

In the aligned optical circuit 300 and optical fiber array 400, during normal operation, an optical signal is emitted from the optical fiber 620d of the optical fiber array 600, and the emitted optical signal is transmitted via the input optical waveguide 550b. It enters the optical switch element 530b and enters the optical switch element 510c or the optical switch element 520c depending on the driving state of the optical switch element 530b. Further, the optical signal incident on the optical switch element 510c or the optical switch element 520c is output to the third input port of the optical splitter element 540a or 540b, 540c or 540d according to the driving state of the optical switch element 510c or 520c. .

As described above, since the optical splitter elements 540a to 540d operate in conjunction with each other, and all the four optical splitter elements 540a to 540d select the third input port, any one of the optical splitter elements 540a to 540d is selected. The optical signal incident on the third input port is output to the output optical waveguide 560a or 560b, 560c or 560d. That is, the optical signal incident from the optical fiber 620d is emitted from one of the output optical waveguides 560a to 560d in the optical circuit 500 according to the driving state of the optical splitter element, and the optical fibers 620a, 620b, 620g of the optical fiber array 600 are emitted. , 620h.

Similarly, optical signals emitted from the optical fibers 620c, 620e, and 620f of the optical fiber array 600 are incident on one of the optical splitter elements 540a to 540d in the optical circuit 500 according to the driving state of the optical splitter element. Then, by switching the four input ports of the optical splitter elements 540a to 540d in conjunction with each other, the optical signals incident from the input optical waveguides 550a to 550d can be appropriately selected and emitted to the optical fiber array 600.

In this embodiment, the aligning optical waveguides 570 and 580 are both drawn to the end face 502 side facing the optical fiber array 600, but the present invention is not limited to this. The aligning optical waveguides 570 and 580 can be drawn to the upper end surface side or the lower end surface side where the optical fiber array 600 is not disposed. Further, a branch may be provided in the middle of the aligning optical waveguides 570 and 580 and drawn out to a plurality of end faces.

Here, in the above embodiment, the core of the optical circuit is formed of silicon and the cladding is formed of quartz glass, but the present invention is not limited to this. For example, the core and the clad can be formed of quartz glass, a compound semiconductor, an organic material, or the like. Even when the core and the clad are formed of these materials, the same effect as the optical circuit described in the above embodiment can be obtained.

In the above embodiment, the optical path of the optical switch element is switched by heating the optical waveguide using a heater, but the present invention is not limited to this. For example, the optical path of the optical switch element can be switched by applying a voltage to the optical waveguide or injecting carriers.

The invention of the present application is not limited to the above-described embodiment, and any design change or the like within a range not departing from the gist of the invention is included in the invention. This application claims priority based on Japanese Patent Application No. 2012-011228 filed on January 23, 2012, the entire disclosure of which is incorporated herein.

The present invention can be applied to all optical devices including a circuit including an optical switch and a connected component connected to the switch.

10, 30, 40, 60 Optical circuit 11, 31, 41, 61 Substrate 12, 32a, 32b Switch 42, 62a, 62b First switch 43a, 43b, 63 Second switch 13, 33a, 33b, 44, 64 Input waveguides 14a, 14b, 34a to 34d, 45a to 45d, 65a to 65d Output waveguides 46a, 46b, 66a, 66b Connection waveguides 15, 35a, 35b, 47, 67a, 67b Adjustment waveguides 20 Alignment System 21 Optical circuit 22 Connected component 23 Measuring means 24 Control means 100, 300, 500 Optical circuit 110a to 110d, 120a, 120b, 130, 310a to 310d, 320a,
320b, 330, 510a to 510d, 520a to 520d, 530a to 530d
Optical switch element 111a Silicon substrate 112a Core 113a Clad 114a, 115a Input port 116a, 117a Output port 140, 340, 550a-550d Input optical waveguide 150a-150h, 350a-350h, 560a-560d Output optical waveguide 160, 170, 360, 370, 570, 580 Alignment optical waveguide 180a to 180f, 380a to 380f Connection optical waveguide 540a to 540d Optical splitter element 200, 400, 600 Optical fiber array 210, 410, 610 Fixed glass block 220a to 220i, 420a to 420i 620a-620h Optical fiber

Claims (10)

1. A substrate,
   In the first state, the first port is connected to the second port and the fourth port is connected to the third port. In the second state, the first port is connected to the third port and the fourth port is connected to the second port. A switch to
   An input waveguide extending from the first port to a predetermined end of the substrate;
   Two output waveguides each extending from the second and third ports to the predetermined end;
   An adjustment waveguide extending from the fourth port to an end other than the predetermined end of the substrate;
   With
   At the time of alignment, the switch is set to the first state, and an optical signal for alignment is input to an output waveguide extending from the third port.
2. The switch includes two optical paths and a switch driving unit disposed in the vicinity of one of the optical paths, and the switch driving unit is switched from the first state to the second state by applying a heat source, applying a voltage, or injecting carriers. The optical circuit according to claim 1, wherein the optical circuit changes to a state.
3. The optical circuit according to claim 1, wherein the switch and the two output waveguides are further arranged on the predetermined end portion side of the output waveguide.
4. The optical circuit according to claim 3, wherein the switch and the two output waveguides are arranged in multiple stages.
5. The optical circuit according to claim 1, further comprising the switch, an input waveguide, two output waveguides, and an adjustment waveguide.
6. The optical circuit according to claim 5, wherein the switch and the input waveguide are further arranged on the predetermined end portion side of the two input waveguides.
7. The optical circuit according to claim 6, wherein the plurality of switches are arranged in parallel, and the plurality of switches connected to the input waveguide are sequentially connected to other switches.
8. At least 4 provided with the some input port and output port which are arrange | positioned at the said predetermined end part side of the output waveguide connected to the said other switch, and each correspond to the some switch connected with the said input waveguide. One optical splitter,
   The optical circuit according to claim 7, wherein a plurality of input ports of the four optical splitters are associated with each other.
9. An optical circuit according to any one of claims 1 to 8,
   A connected component including optical fibers connected to the input waveguide and the output waveguide of the optical circuit, and
   A measuring means disposed at a position opposite to the adjustment waveguide and measuring the intensity of the adjustment optical signal emitted from the adjustment waveguide;
   Control means for controlling the relative position between the optical circuit and the connected component so that the measured intensity is maximized;
   With
   When aligning the optical circuit and the connected component,
   The alignment system according to claim 1, wherein the switch is set in the first state, and the connected component outputs an alignment optical signal to an output waveguide extending from the third port.
10. In the first state, the first port is connected to the second port, and the fourth port is connected to the third port. In the second state, the first port is connected to the third port, and the fourth port is the second port. The connected component is brought close to a predetermined end of the substrate of the optical circuit having a switch to be connected to
    In the first state,
    An optical signal is input from an output waveguide extending from the third port;
    Measuring the intensity of the optical signal output from the adjustment waveguide extending from the fourth port to an end other than the predetermined end of the substrate;
    The position where the measured intensity is maximum is the alignment position,
    Optical circuit alignment method.

Images