JP3031307B2 - Optical waveguide device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical waveguide device used in an optical communication system using wavelength division multiplexing.

[0002]

2. Description of the Related Art With the advent of the multimedia society, the demand for an increase in information transmission capacity has been rapidly increasing. As a means for this, an optical communication system using wavelength division multiplexing (WDM) has attracted attention and has been developed by many organizations. Is being promoted. In particular, WD
Attempts have been made to adopt the M method in an optical communication network to greatly increase the total information transmission throughput.

In such a situation, for example, an optical ADM in which some signals are extracted and received from 16 multiplexed signal lights, and optical signals of different bit patterns of the same wavelength are inserted at the same port. (ADD DROP MULTIPLEXING)
Functionality has been strongly demanded. As one example, an optical waveguide device in which a plurality of arrayed waveguide grating (AWG) type wavelength filters are integrated is disclosed in JP-A-7-3189.
No. 87 is disclosed.

Hereinafter, this optical waveguide device will be described.
This will be described with reference to FIG. FIG. 7 is a plan view of a conventional optical waveguide device.

In the example shown in FIG. 7, first to third AWGs 102a, 102b and 102c, first and second input optical waveguides 103 and 105, and first and second output Optical waveguides 104 and 106 and a plurality of 2 ×
It has a structure in which the two-optical switch 107 is integrated.
The first input optical waveguide 103 is connected to the input side of the first AWG 102a. The first output optical waveguide 104 is connected to the output side of the second AWG 102b,
A second output optical waveguide 10 is provided on the output side of the AEG 102c.
6 are connected. The first AWG 102a is one input port of the 2 × 2 optical switch 107, and the second and third AWGs 102b and 102c are 2 × 2 optical switches 1
07 output port. Further, the other input port of the 2 × 2 optical switch 107 is the second input optical waveguide 1
05. As the 2 × 2 optical switch 107, a switch using a thermo-optic effect of a quartz system is used.

[0006] The WDM signal input from the first input optical waveguide 103 is wavelength-separated by the first AWG 102a, and on the output side, the 2 × 2 optical switch 1 is used for each channel.
07, the second AWG 102b or the third AWG
102c. For example, 16 multiplexed WDM
In the signal light, if the signals of the fifth and eighth channels are extracted (DROP) and a signal of the same wavelength but a different bit pattern is newly introduced (ADD), the second input optical waveguide is used. A signal may be introduced into the channel of the wave path 105 where a new signal is to be introduced, that is, the fifth and eighth channels. As a result, a desired optical signal can be extracted or introduced from among a large number of different signal lights having light of different wavelengths as carriers and transmitted to the loop network.

The operation principle of the above-described optical waveguide device will be described with reference to FIG. FIG. 8 is a schematic diagram for explaining the operation principle of a conventional optical waveguide device having an optical ADM function. Although FIG. 8 shows a case where two AWGs are provided for simplification of description, the optical waveguide device shown in FIG. 7 is different from the second output optical waveguide 116 shown in FIG. Is equivalent to another AWG being connected to the end of the AWG.

[0008] In the optical waveguide device shown in FIG.
The signal input from the input optical waveguide 113 is input side AW
After wavelength separation by G112a, the optical switch 11
7 and is output to either the output side AWG 112b or the second optical output waveguide 116. For example, when extracting the signal of the wavelength of the seventh channel by 16-wavelength multiplexing, only the optical signal of that channel is cross-ported (off state) by the optical switch 117.
If all the other channels are in the bar port state (ON state), only the seventh signal is output to the second output optical waveguide 116, and the signals of the other channels are introduced to the output side AWG 112b. Here, if an optical signal having the same wavelength as that of the seventh channel but having a different bit pattern is introduced from the second input optical waveguide 115, the optical switch 117 for the seventh channel is in the OFF state. The optical signal introduced from the second input optical waveguide 115 is introduced to the output side AWG 112b. As a result, from the first output optical waveguide 114, a new optical signal of the seventh channel and an optical signal of another channel flowing on the network are added and output.

[0009]

However, in the above-described conventional optical waveguide device, a high-speed response in nanoseconds cannot be obtained because an optical switch utilizing the thermo-optic effect of quartz is used. There was a point. In general, such an optical switch has a crosstalk of -30.
It is difficult to suppress the noise to as low as about -40 dB, and there is a case where the waveform is deteriorated due to the interference between the signal lights.

In an optical network, the original W
There is also a demand for operating a DM signal in a broadcast mode utilizing the network as it is, and extracting a signal of a certain wavelength. In a conventional optical waveguide device, switching is performed by an optical switch.
0% was switched, and it was not possible to leave a part of the broadcast mode as it was on the network.

Further, since the ends of the input optical waveguide and the output optical waveguide are located at various positions on the plurality of surfaces of the substrate, the mounting of the input and output optical fibers becomes complicated.

An object of the present invention is to provide an optical waveguide device having an optical ADM function, which can provide a high-speed response in a nanosecond order, sufficiently suppress crosstalk, and can be used even in a broadcast mode. I do.

[0013]

In order to achieve the above object, an optical waveguide device of the present invention separates an optical signal input from a first input optical waveguide for each wavelength, and separates the optical signal separated for each wavelength. Wavelength multiplexing / demultiplexing means for superimposing and outputting from the first output optical waveguide, and an optical waveguide connected to an output side and an input side of the wavelength multiplexing / demultiplexing means to constitute a loop circuit together with the wavelength multiplexing / demultiplexing means And an optical gate for blocking an optical signal of an arbitrary wavelength among the optical signals separated by the wavelength multiplexing / demultiplexing means, and an optical signal having the same wavelength as the optical signal blocked by the optical gate. A second input optical waveguide connected to one of the input side and the output side of the wavelength multiplexing / demultiplexing means, and all the optical signals separated by the wavelength multiplexing / demultiplexing means, Before passing through the light gate, And a second output optical waveguide for outputting by branching from the road.

In the optical waveguide device of the present invention configured as described above, the optical signal input from the first input optical waveguide is separated for each wavelength by the wavelength multiplexing / demultiplexing means, and then the optical gate is provided. And output to the loop circuit and the second output optical waveguide. From the optical signal output to the loop circuit, an optical signal having a desired wavelength is extracted by the optical gate, and is again output from the first output optical waveguide through the wavelength multiplexing / demultiplexing means. Here, if a new optical signal having the same wavelength as the wavelength of the extracted optical signal is input from the second input optical waveguide, the optical signal of the desired wavelength is replaced from the first output optical waveguide. An optical signal is output. On the other hand, optical signals of all wavelengths are output from the second output optical waveguide irrespective of extraction of optical signals at the optical gate. Further, since an optical gate is used for extracting an optical signal, crosstalk is suppressed and the response speed is high.

In a preferred embodiment, the second input optical waveguide comprises a plurality of optical waveguides corresponding to the number of optical signals separated by the wavelength multiplexing / demultiplexing means, and is connected to the input side of the wavelength multiplexing / demultiplexing means. You. Alternatively, the second input optical waveguide is constituted by one optical waveguide, and is joined and connected to the first output waveguide in the middle of the first output waveguide. Preferably, the wavelength multiplexing / demultiplexing means is an arrayed waveguide grating. Furthermore, a light receiving element is connected to the second output optical waveguide through a second optical gate and an optical combiner that selectively transmit an optical signal of an arbitrary wavelength among optical signals passing through the second output optical waveguide. May be adopted.

Further, by forming each of the above elements on a single semiconductor substrate, the optical waveguide device of the present invention can
Implemented in chips. Further, by arranging the input end of the input optical waveguide and the output end of the output optical waveguide on one end surface of the semiconductor substrate, it becomes easy to mount the optical fiber on each of the input end and the output end.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Before that, the basic concept of the present invention will be described with reference to FIG.

FIG. 1 is a schematic view for explaining the operation principle of the optical waveguide device of the present invention. In FIG. 1, an optical signal input from a first input optical waveguide 1 is wavelength-separated by an input-side AWG 2a which is a wavelength demultiplexing device,
Each of the Y-branch optical waveguides 8 divides the optical gate 7 and the second output optical waveguide 6 at a ratio of about 1: 1. The output side of the optical gate 7 is connected to an output side AWG 2b, which is a wavelength multiplexing device, via a Y-branch optical waveguide 9 to which the second input optical waveguide 5 is connected. As the optical gate 7, for example, a semiconductor amplifier is used.

In the optical waveguide device configured as described above, of the optical signals wavelength-separated by the input side AWG 2a,
By blocking the optical signal of a certain channel by the optical gate 7, the optical signal of that channel can be extracted. Then, by introducing an optical signal having the same wavelength as the extracted channel but a different bit pattern from the second input optical waveguide 5, the optical signal from the optical gate 7 and the optical signal from the second input optical waveguide 5 are introduced. Of the output side AW
The signals are added at G2b and output from the second output optical waveguide 4.

On the other hand, regardless of which channel an optical signal is extracted, the second output optical waveguide 6 has an input side AWG.
Since optical signals of all wavelengths separated by the wavelength 2a are output, communication in the broadcast mode becomes possible. Further, since the optical gate 7 is used instead of the conventional optical switch, it is easy to suppress the crosstalk to -50 dB or less, and the response speed is as high as nanoseconds.

(First Embodiment) FIG. 2 is a plan view of an optical waveguide device according to a first embodiment of the present invention.

As shown in FIG. 2, the optical waveguide device according to the present embodiment comprises, on a substrate 11 made of Si, an AWG 12 made of an optical waveguide, an optical gate 17, a first and a second input optical waveguides 13, 15, first and second output optical waveguides 14 and 16, AWG output-side optical waveguide 18, AE
The configuration is such that the G input side optical waveguide 19 is integrated.

The AWG 12 has a function of separating an input wavelength-division multiplexed optical signal for each wavelength, and superimposing and outputting the separated optical signals.

On the input side of the AWG 12, a first input optical waveguide 13 and an array of second input optical waveguides 15 corresponding to the number of signals separated by the AWG 12 are connected.
On the output side of the AWG 12, a first output optical waveguide 14,
The arrayed second output optical waveguides 16 corresponding to the number of signals separated by the AWG 12 are connected. Input ends of the first and second input optical waveguides 13 and 15;
The output ends of the output optical waveguides 14 and 16 are
1 are located on the same end face. This facilitates mounting of the optical fiber at each of the input and output ends.

Further, an AWG output-side optical waveguide 18 in an array is connected to the output side of the AWG 12 so as to be branched from the second output optical waveguide 16. AWG
The output-side optical waveguide 18 is connected to an array-shaped AWG input-side optical waveguide 19 via an optical gate 17, and the AWG input-side optical waveguide 19 is connected to the input of the AWG 12 in such a manner as to merge with the second input optical waveguide 15. Connected to the side. Thus, a loop circuit is formed by the AWG 12, the AWG output side optical waveguide 18, the optical gate 17, and the AWG input side optical waveguide 19.

A typical example of the optical waveguide formed on the substrate is a silica-based optical waveguide. The cross-sectional structure of the quartz optical waveguide will be described with reference to FIG.

A lower cladding layer 2 made of PSG (phosphorus-doped quartz glass) is formed on a substrate 11 made of Si.
1 formed thereon, and a GPS obtained by adding Ge to PSG
A core layer 22 made of G is formed by patterning into a shape of an optical waveguide. Then, an upper clad layer 23 having the same composition as that of the lower clad layer 21 is formed on the lower clad layer 21 on which the core layer 22 is formed, thereby covering the core layer 22.

On the other hand, the optical gate 17 is formed of a semiconductor optical amplifier. The structure of the optical coupling portion between the optical gate and the quartz optical waveguide will be described with reference to FIG. As described above, the silica-based optical waveguide includes the core layer 22 sandwiched between the lower clad layer 21 and the upper clad layer 23. The optical gate 17 has an active layer 31 buried so that the active layer 31 is at the same height as the end face of the core layer 22. The positions of the active layer 31 and the core layer 22 in the height direction are aligned by solder bumps 32 fixing the optical gate 17.

The operation of the optical waveguide device according to the present embodiment will be described below by taking, as an example, a case where only the signal of the seventh channel is extracted or newly introduced by 16-wavelength multiplexing.

The wavelength-division multiplexed signal introduced from the first input optical waveguide 13 travels from the right to the left in the AWG 12 in the figure, and after being wavelength-separated, is separated into the second output optical waveguide 16 and the AWG output-side optical waveguide 18. It is split and output. That is, the signals of all the separated wavelengths are output to the second output optical waveguide 16 and the AWG output side optical waveguide 18. Thus, signals of all wavelengths can be output from the second output optical waveguide 16, so that broadcast mode communication is also possible.

The signal input to the AWG output side optical waveguide 18 reaches the optical gate 17. Here, when the signal of the seventh channel is blocked by the optical gate 17, only the signals of the other channels are introduced again into the AWG 12 through the AWG input side optical waveguide 19, and the first output optical waveguide 1
4 is wavelength-multiplexed and output. An optical gate 1 is used to extract a signal of a predetermined channel from the wavelength-separated signal.
7, the crosstalk can be kept extremely low, and a high-speed response in a nanosecond unit can be achieved.

When a new optical signal having the same wavelength as the signal of the seventh channel is input from the port corresponding to the seventh channel of the second input optical waveguide 15, the signal passes through the AWG 12 and The signal is wavelength-multiplexed with a signal of another channel and output from the first output optical waveguide 14.

Further, the optical waveguide device of the present embodiment comprises an AWG 12, an optical gate 17, first and second input optical waveguides 13 and 15, first and second output optical waveguides 14 and 16, AWG output side optical waveguide 18 and AE
Since the configuration is such that the G-input-side optical waveguide 19 and the G-input-side optical waveguide 19 are integrated on one substrate 11, the above-described functions can be realized by one chip.

In this embodiment, the signal passes through one AWG 12 twice. However, a plurality of AWGs are provided, and the signal after wavelength selection and the newly added signal are combined by another AWG. It is good also as a structure which performs. The substrate 11 is made of Si, but is not limited thereto.
A substrate made of nP may be used.

(Second Embodiment) FIG. 5 is a plan view of a second embodiment of the optical waveguide device according to the present invention.

The optical waveguide device of this embodiment is an AWG
42, a configuration for inputting a signal from the outside and a configuration for outputting a signal to the outside with respect to a loop circuit including the AWG output side optical waveguide 48, the optical gate 47 and the AWG input side optical waveguide 49. , Is different from the first embodiment.

Hereinafter, the present embodiment will be described focusing on parts different from the first embodiment. The first optical waveguide 43 and an AWG input optical waveguide 49 in an array are connected to the input side of the AWG 42. Further, the second input optical waveguide 45 is formed of one optical waveguide, and the first input optical waveguide 45 is connected to the output side of the AWG 42 in the middle of the first output optical waveguide 44.
And is connected to the output optical waveguide 44. An optical amplifier 51 is provided on the distal end side of the first output optical waveguide 44 with respect to the junction with the second input optical waveguide 45.

The second output optical waveguide 46 connected to the output side of the AWG 42 is provided with a second optical gate 52. Further, an optical combiner 53 is connected to the end of the second optical gate 52, and a light receiving element 54 is connected to the optical combiner 53. The second optical gate 52 selectively transmits only a signal having a desired wavelength among signals passing through the second output optical waveguide 46 and blocks a signal having another wavelength.

The optical combiner 53 will be described with reference to FIG. The optical combiner 53 is a multi-input, one-output type. The input side is a single-mode optical waveguide 62, and the output side is a multi-mode optical waveguide 63, which are coupled by an optical coupler 61. The input portion of the single mode optical waveguide 62 to the optical coupler 61 has a structure in which the width of the waveguide is widened in order to increase the light spot size.

For example, when handling 16-wavelength multiplexed signals,
The number of single mode optical waveguides 62 is 16, each width is 6 μm, and the width of multimode optical waveguide 63 is 50 μm.
Assuming m, the total loss is 1.5 dB, which can be suppressed to a much lower loss than the 12 dB principle loss in a method combining a normal coupler.

As the light receiving element 54, an InGaAs-based waveguide PIN-PD, APD, or the like is used.

Each of the above-mentioned elements is made of Si or In.
It is integrated on one substrate 41 made of P or the like.

In the optical waveguide device of the present embodiment configured as described above, the wavelength multiplexed signal introduced from the first input optical waveguide 43 is wavelength-separated by the AWG 42, and each of the separated signals is output to the AWG output side. The light is split into an optical waveguide 48 and a second output optical waveguide 46 and output.

The signal input to the AWG output side optical waveguide 48 is again introduced into the AWG 42 through the optical gate 47 and the AWG input side optical waveguide 49. At this time, if the signal of the desired channel is blocked by the optical gate 47, only the signal of the unblocked channel is A
Introduced to WG42. Here, a new signal having the same wavelength as the signal of the channel blocked by the optical gate 47 is set to the second signal.
Input from the input optical waveguide 45, the signal is AW
The signal is multiplexed with the wavelength-division multiplexed signal output from G42 to the first output optical waveguide 44, amplified by the optical amplifier 51, and output from the first output optical waveguide 44 to the outside.

On the other hand, only the signal of a desired wavelength is transmitted by the second optical gate 52 from the signal input to the second output optical waveguide 46, and the light is received by the light receiving element 5 through the optical combiner 53.
4 is input. The signal input to the light receiving element 54 is converted into an electric signal by the light receiving element 54, amplified by an external electric receiving amplifier, and operates as a receiver. Light receiving element 54
Are received with high reception sensitivity because the loss due to the optical combiner 53 is small. Here, the amplifier is provided outside, but it may be flip-chip mounted on the substrate 41.

The second optical gate 52, the optical combiner 53 and the light receiving element 54 provided in the present embodiment are applied to the first embodiment, and the second output optical waveguide 16 ( These may be connected to (see FIG. 2).

[0047]

Embodiments of the present invention will be described below.

This embodiment is an embodiment of the embodiment shown in FIG. As the substrate 11, a Si substrate was used.
Various optical waveguides formed on the substrate 11 were quartz optical waveguides.

The step of forming a silica-based optical waveguide in this embodiment will be described with reference to FIG. First, on the substrate 11, a normal pressure CVD method using TEOS and ozone is used.
A lower clad layer 21 made of PSG was laminated with a thickness of 15 μm, and a GPSG film was further laminated with a thickness of 6 μm. This GPSG film is patterned into the shape of an optical waveguide, and the
Etching was performed by an E (reactive ion etching) method to form the core layer 22. The width of the core layer 22 is 6 μm
And the refractive index with the cladding layer was 0.35%. Further, an upper clad layer 23 made of PSG is laminated thereon with a thickness of 15 μm, whereby an optical waveguide is formed on the substrate 11.

As a result of forming the optical waveguide in this manner, the second
Output optical waveguide 16 and AWG output-side optical waveguide 18, and second input optical waveguide 15 and AWG input-side optical waveguide 1
Excess loss at the branching point with No. 9 was 0.3 db or less, and good characteristics were obtained. The AWG 12 has 17 ports on both the input side and the output side. That is,
On the input side, the port for the first input optical waveguide is 1
First, there are 16 ports for the second input optical waveguide, and on the output side, there is one port for the first output optical waveguide and 16 ports for the second output optical waveguide. AW
G12 has a wavelength interval of 0.8 nm (100 GHz) and a crosstalk of -30 dB or less.

As the optical gate 17, an InGaAsP-based semiconductor optical amplifier was used. The length of the optical gate 17 is 500 μ
m, number of channels is 16, pitch in left and right direction is 125μ
m. A signal gain of 25 dB or more is obtained as a signal gain by current injection of 50 mA. A spot size converter is formed in an input / output part for high-efficiency coupling with a silica-based optical waveguide. At 15
A gain of about dB was realized. The end face of the optical waveguide at the optical coupling portion between the optical gate 17 and the optical waveguide is formed by RIE, and the height direction and the lateral direction of the active layer 31 of the optical gate 17 and the optical waveguide are aligned with solder bumps. 32, using a passive alignment technique.

Using such an optical waveguide device, 1
When the reception evaluation of the wavelength multiplexed signal of 6 channels was performed, the reception sensitivity of −30 dBm was obtained for the signal light of 2.5 Gb / s, and the high-speed operation of 3 ns or less was performed as the signal channel switching speed. I realized it. The crosstalk at the optical gate 17 is -45 dB.
Met. Comprehensively, it was confirmed that a good optical ADM operation was performed.

[0053]

As described above, according to the present invention, a loop circuit is connected to the output side and the input side of the wavelength multiplexing / demultiplexing means together with the wavelength multiplexing / demultiplexing means for extracting an optical signal having a desired wavelength. All optical signals separated by the wavelength multiplexing / demultiplexing means are branched off from the optical waveguide before passing through the optical gate and output from the second output optical waveguide using the optical gate provided in the optical waveguide to be constituted. With this configuration, it is possible to provide an optical waveguide device having an optical ADM function, capable of high-speed response in nanosecond units, sufficiently suppressing crosstalk, and being usable even in a broadcast mode.

Further, by forming each element such as the optical waveguide on one semiconductor substrate, the optical waveguide device of the present invention can be realized by one chip. Further, by disposing the input end of the input optical waveguide and the output end of the output optical waveguide on one end surface of the semiconductor substrate, an optical fiber can be easily mounted on each input end and output end.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining the operation principle of an optical waveguide device according to the present invention.

FIG. 2 is a plan view of the first embodiment of the optical waveguide device of the present invention.

FIG. 3 is a cross-sectional view illustrating a structure of a silica-based optical waveguide.

FIG. 4 is a cross-sectional view showing an optical coupling structure between an optical gate and a silica-based waveguide.

FIG. 5 is a plan view of a second embodiment of the optical waveguide device of the present invention.

FIG. 6 is a plan view of the optical combiner.

FIG. 7 is a plan view of a conventional optical waveguide device.

FIG. 8 is a schematic diagram for explaining the operation principle of a conventional optical waveguide device.

[Explanation of symbols]

 2a Input side AWG 2b Output side AWG 3,13,43 First input optical waveguide 4,14,44 First output optical waveguide 5,15,45 Second input optical waveguide 6,16,46 Second output Optical waveguide 7, 17, 47 Optical gate 8, 9 Y branch optical waveguide 11, 41 Substrate 12, 42 AWG 18, 48 AWG output optical waveguide 19, 49 AWG input optical waveguide 21 Lower cladding layer 22 Core layer 23 Upper cladding Layer 31 Active layer 32 Solder bump 51 Optical amplifier 52 Second optical gate 53 Optical combiner 54 Light receiving element 61 Optical coupler 62 Single-mode optical waveguide 63 Multi-mode optical waveguide

Claims (9)

(57) [Claims] 1. A wavelength multiplexing / demultiplexing means for separating an optical signal input from a first input optical waveguide for each wavelength, superimposing optical signals separated for each wavelength, and outputting from a first output optical waveguide. An optical signal connected to an output side and an input side of the wavelength multiplexing / demultiplexing means, and provided in an optical waveguide forming a loop circuit together with the wavelength multiplexing / demultiplexing means, An optical gate that blocks an optical signal of an arbitrary wavelength, and either one of the input side or the output side of the wavelength multiplexing / demultiplexing means to input an optical signal having the same wavelength as the optical signal blocked by the optical gate. A second input optical waveguide to be connected, and a second optical signal branching out all the optical signals separated by the wavelength multiplexing / demultiplexing means from the optical waveguide before the optical signal passes through the optical gate. Waveguide having two output optical waveguides device. 2. The second input optical waveguide includes a plurality of optical waveguides corresponding to the number of optical signals separated by the wavelength multiplexing / demultiplexing means, and is connected to an input side of the wavelength multiplexing / demultiplexing means. The optical waveguide device according to claim 1, wherein: 3. The second input optical waveguide is constituted by one optical waveguide, and the first output waveguide is provided in the middle of the first output waveguide.
2. The optical waveguide device according to claim 1, wherein the optical waveguide device is connected to the output waveguide of the optical waveguide. 4. The optical waveguide device according to claim 1, wherein said wavelength multiplexing / demultiplexing means is an arrayed waveguide grating. 5. The second output optical waveguide further includes a second output optical waveguide.
5. The light receiving element according to claim 1, wherein the light receiving element is connected via a second optical gate and an optical combiner which selectively transmit an optical signal of an arbitrary wavelength among the optical signals passing through the output optical waveguide. An optical waveguide device according to any of the preceding claims. 6. The optical waveguide device according to claim 1, wherein each of the optical waveguides, the wavelength multiplexing / demultiplexing means, and the optical gate are formed on a single semiconductor substrate. 7. The semiconductor device according to claim 6, wherein the input terminals of the first and second input optical waveguides and the output terminals of the first and second output optical waveguides are arranged on one end surface of the semiconductor substrate.
3. The optical waveguide device according to claim 1. 8. Each of the optical waveguides, the wavelength multiplexing / demultiplexing means,
The optical waveguide device according to claim 5, wherein the optical gate, the second optical gate, the optical combiner, and the light receiving element are formed on one semiconductor substrate. 9. The semiconductor device according to claim 8, wherein the input terminals of the first and second input optical waveguides and the output terminal of the first output waveguide are arranged on one end surface of the semiconductor substrate. Optical waveguide device.