JP4916571B2 - Optical circuit and optical signal processing apparatus using the same - Google Patents

Description

  The present invention relates to an optical circuit and an optical signal processing apparatus using the same, and more specifically, an optical circuit capable of extracting a part of an input or output optical signal as a monitor optical signal and an optical signal processing apparatus using the optical circuit. About.

  With the development of information communication technology, there is a demand for an increase in communication capacity and speed. As a technology that meets these demands, the introduction of a wavelength division multiplexing (WDM) system that transmits and receives wavelength multiplexed optical signals (WDM optical signals) in which optical signals of different wavelengths are multiplexed is being promoted. Various nodes in a WDM system that transmits and receives WDM optical signals monitor each optical signal before and after multiplexing to the WDM optical signal or before and after wavelength separation from the WDM optical signal. Level adjustment is performed.

  As shown in FIG. 1A, a signal having a different wavelength from the input of a conventional device 102 (hereinafter also referred to as MUX (multiplexer)) that multiplexes signal light having different wavelengths into a WDM optical signal. Taps 104 (for example, directional couplers and optical couplers) corresponding to the number of wavelengths of the optical signal multiplexed into the WDM optical signal are output to the output of the device 103 for wavelength separation into light (hereinafter also referred to as DEMUX (de-multiplexer)). Etc.) and a method for extracting a part of the optical signal as a monitor optical signal is known. Further, as shown in FIG. 1B, conventionally, a tap 104 is arranged at the output of the MUX 102 or the input of the DEMUX 103 to extract a part of the WDM optical signal, and the WDM optical signal extracted by the tap 104 is separated from another. A method is known in which each signal light is extracted as a monitor light signal after wavelength separation by the DEMUX 106.

  In addition, as shown in FIG. 2, conventionally, an arrayed waveguide grating 202 (AWG: Arrayed Waveguide Grating) in the DEMUX is configured to generate high-order diffracted light together with zero-order diffracted light of each optical signal to be wavelength-separated, A method for extracting high-order diffracted light of each optical signal as a monitor optical signal is known (see, for example, Patent Document 1).

  Furthermore, as shown in FIG. 3, after tapping a plurality of WDM optical signals output from a wavelength selection device (WSR: wavelength-separating routing or WSS: Wavelength Selective Switch) for each WDM optical signal, each wavelength is further separated. A method for monitoring the optical signal is known (see, for example, Patent Document 2).

Japanese Patent No. 3687529 (paragraph 0076, Fig. 1) US Pat. No. 6,549,699 (column 11, lines 11 to 34, FIG. 4A)

  However, the conventional example shown in FIG. 1 has a problem that more elements or members are added to the MUX or DEMUX in order to extract the monitor optical signal.

  Further, the conventional example shown in FIG. 2 has a problem that the tap ratio is not uniform because the branching ratio to the higher-order diffracted light is sensitive to the structure of the AWG. In addition, since the branching ratio to the higher-order diffracted light has a high wavelength dependency, there is a problem that the tap ratio has a wavelength dependency.

  Further, the conventional example shown in FIG. 3 has a problem that the number of elements or members to be added to the wavelength selection device increases as in the conventional example shown in FIG.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an optical circuit in which additional elements or additional members for extracting a monitor optical signal are reduced or an optical signal processing apparatus using the optical circuit. The purpose is to provide. Another object of the present invention is to provide an optical circuit that extracts 0th-order diffracted light instead of high-order diffracted light as monitor light, or an optical signal processing device using the same.

  An optical circuit according to one aspect of the present invention includes an optical branching unit for branching input light at a predetermined ratio, a slab waveguide, and a predetermined optical path length connected to the slab waveguide. An arrayed waveguide having a difference, and coupling means for coupling light from the arrayed waveguide to a predetermined optical path or coupling light from a predetermined optical path to the arrayed waveguide.

  In one embodiment, the optical branching unit branches a WDM optical signal in which optical signals of a plurality of wavelengths are multiplexed, the arrayed waveguide wavelength-separates each of the branched WDM optical signals, and the coupling unit includes The optical signals wavelength-separated from one of the branched WDM optical signals and the optical signals wavelength-separated from the other of the branched WDM optical signals are coupled to different optical paths.

  In one reference example, the optical branching unit branches a WDM optical signal in which optical signals of a plurality of wavelengths are multiplexed, and the slab waveguide passes one of the branched WDM optical signals to the arrayed waveguide. And the coupling means couples the other of the branched WDM optical signals to the arrayed waveguide, the arrayed waveguide wavelength-separating each of the branched WDM optical signals, and the branched WDM. Each optical signal wavelength-separated from one of the optical signals is coupled to the coupling means, and each optical signal wavelength-separated from the other of the branched WDM optical signals is coupled to the slab waveguide, and the slab waveguide And the coupling means couples each optical signal wavelength-separated from one of the branched WDM optical signals and each optical signal wavelength-separated from the other of the branched WDM optical signals to different optical paths.

  In one embodiment, the coupling means couples optical signals of a plurality of wavelengths to the arrayed waveguide, and the arrayed waveguide synthesizes the optical signals of the plurality of wavelengths into a WDM optical signal, and performs the slab guiding. A waveguide couples the WDM optical signal to the branching means, the branching means branches the WDM optical signal, and the coupling means couples one of the branched WDM optical signals to the arrayed waveguide. The arrayed waveguide wavelength-separates one of the branched WDM optical signals, couples the wavelength-separated optical signals to the slab waveguide, and the slab waveguide outputs the WDM optical signal. The wavelength-separated optical signals are coupled to an optical path different from the optical path.

  In one embodiment, the coupling means couples optical signals of a plurality of wavelengths to the arrayed waveguide, and the arrayed waveguide synthesizes the optical signals of the plurality of wavelengths into a WDM optical signal, and performs the slab guiding. The waveguide couples the WDM optical signal to the branching means, the branching means branches the WDM optical signal, couples one of the branched WDM optical signals to the slab waveguide, and the slab waveguide. Couples one of the branched WDM optical signals to the arrayed waveguide, the arrayed waveguide wavelength-separates one of the branched WDM optical signals, and combines the wavelength-separated optical signals. The coupling means couples the wavelength-separated optical signals to an optical path different from the optical path to which the optical signals having the plurality of wavelengths are input.

  In one embodiment, the coupling means may be a second slab waveguide connected to the arrayed waveguide fabricated on the same substrate as the substrate on which the arrayed waveguide is fabricated. It can also be.

  An optical signal processing apparatus according to an aspect of the present invention includes the optical circuit in which the coupling unit is configured by a spatial optical element, a light detection unit, and a signal processing element, and the spatial optical element includes the array waveguide. The light from the waveguide is coupled to the optical path for inputting to the signal processing element, or the light from the signal processing element is coupled to the optical path for inputting to the array waveguide, and the light from the array waveguide is transmitted to the light detection means. It is characterized by being coupled to an input optical path.

  As described above, according to the present invention, it is possible to provide an optical circuit in which additional elements or additional members for extracting a monitor optical signal are reduced. Further, according to the present invention, it is possible to provide an optical circuit that extracts 0th-order diffracted light instead of high-order diffracted light as monitor light. In addition, it is possible to provide an optical signal processing device using these optical circuits.

(A) And (b) is a figure for demonstrating the outline of the conventional wavelength multiplexing apparatus and a wavelength separation apparatus. It is a figure for demonstrating the outline of the conventional wavelength separation apparatus. It is a figure for demonstrating the outline of the conventional wavelength selection apparatus. It is a schematic block diagram of the optical circuit of the 1st reference example of this invention. FIG. 5 is an external schematic diagram of an optical circuit of a second reference example of the present invention and an optical signal processing device using the optical circuit. It is a schematic block diagram of the optical circuit of the 3rd reference example of this invention. FIG. 10 is an outer schematic diagram of an optical circuit and an optical signal processing apparatus using the optical circuit according to a fourth reference example of the present invention. It is a schematic block diagram of the optical circuit of the 1st Example of this invention. FIG. 5 is an external schematic diagram of an optical circuit and an optical signal processing apparatus using the same according to a second embodiment of the present invention. It is a schematic block diagram of the optical circuit of the 3rd Example of this invention. FIG. 6 is an external schematic diagram of an optical circuit and an optical signal processing apparatus using the same according to a fourth embodiment of the present invention. It is a schematic block diagram of the optical circuit of the 5th Example of this invention. FIG. 10 is an external schematic diagram of an optical circuit and an optical signal processing apparatus using the same according to a sixth embodiment of the present invention. It is a schematic block diagram of the optical circuit of the 7th Example of this invention. FIG. 10 is an external schematic diagram of an optical circuit and an optical signal processing apparatus using the same according to an eighth embodiment of the present invention. It is a schematic block diagram of the optical signal processing apparatus using the optical circuit of the Example of this invention. It is a schematic block diagram of the optical signal processing apparatus using the optical circuit of the Example of this invention. It is a schematic block diagram of the optical signal processing apparatus using the optical circuit of the Example of this invention. It is a schematic block diagram of the optical signal processing apparatus using the optical circuit of the Example of this invention. It is a schematic block diagram of the optical signal processing apparatus using the optical circuit of the Example of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or similar reference numerals are used for the same or similar elements, and repeated description is omitted.

  An optical circuit (500) according to the present invention includes an optical branching unit (504), a slab waveguide (506), and a slab waveguide, which are respectively fabricated on a substrate (501) and branch input light at a predetermined ratio. An array waveguide (508) connected to the waveguide, and coupling means for coupling light from the array waveguide (508) to a predetermined optical path or coupling light from the predetermined optical path to the array waveguide (508) B; 510; 902, 904).

  The coupling means can be composed of a slab waveguide (510) fabricated on the same substrate as the arrayed waveguide (508) or a spatial optical element (902, 904) such as a lens. The branching means can be constituted by a directional coupler (504) or a multimode interference coupler.

  The optical circuit according to the present invention can be used as one element constituting the MUX or DEMUX.

  The optical circuit according to the present invention can be used together with the signal processing element (906) to constitute an optical signal processing device.

  In this specification, the horizontal direction of the signal light emission end face on the substrate of the optical circuit is x, the vertical direction is y, and the traveling direction of the light wave, that is, the optical axis is z.

  A first reference example of the present invention will be described with reference to FIG. FIG. 4 is a diagram illustrating a schematic configuration of the optical circuit 500 of the reference example. The optical circuit 500 of this reference example outputs each optical signal obtained by wavelength-separating a part of the input WDM optical signal as a main optical signal, and each wavelength-separated part of the remaining part of the input WDM optical signal. It is an optical circuit that can output signal light as a monitor optical signal, and can be used as a component constituting a DEMUX device.

  The optical circuit 500 of the present reference example shown in FIG. 4 includes a 4-port directional coupler 504, which is fabricated on a substrate 501 and branches incident light at a predetermined ratio, a slab waveguide 506, and a slab guide. And an arrayed waveguide 508 connected to the waveguide 506. Furthermore, the optical circuit of this reference example includes a slab waveguide 510 as a coupling means for coupling an optical signal output from the arrayed waveguide 508 to a predetermined optical path. In the optical circuit of this reference example, the coupling means B is constituted by a slab waveguide 510 fabricated on the same substrate 501 as the substrate on which the arrayed waveguide 508 is fabricated.

  The optical circuit 500 of this reference example includes an optical waveguide 502 for inputting an optical signal, an optical waveguide 512 for outputting a main optical signal branched from the optical signal, and monitor light branched from the optical signal. And an optical waveguide 514 for outputting a signal. Optical waveguides 512 and 514 are each connected to slab waveguide 510. That is, the main optical signal and the monitor optical signal from the arrayed waveguide 508 are coupled to the optical waveguides 512 and 514 that are the respective predetermined optical paths by the slab waveguide 510 and output. When the number of wavelengths of a WDM optical signal multiplexed with optical signals of a plurality of wavelengths input from the optical waveguide 502 is N (integer of 2 or more), the number of optical waveguides 512 and 514 is N.

  The arrayed waveguide 508 has a predetermined optical path length difference, and outputs the WDM signal input from the slab waveguide 506 after wavelength separation. When the bandwidth of a WDM optical signal multiplexed with optical signals of a plurality of wavelengths input from the waveguide 502 is F (Hz), the arrayed waveguide 508 has a free spectral region of at least 2 F (Hz). It is configured.

  The directional coupler 504 includes optical waveguides 504-1 to 504-4 respectively corresponding to the ports 1 to 4, and splits the input light into two at a predetermined branching ratio (for example, 9 to 1) and outputs the branched light. For example, in the directional coupler 504, 9/10 of the optical signal input from the port 1 is output to the port 3, and 1/10 of the optical signal input from the port 1 is output to the port 4. Similarly, nine tenths of the optical signal input from port 3 is output to port 1, and one tenth of the optical signal input from port 3 is output to port 2.

  In this reference example, the optical waveguide 504-1 is connected to the optical waveguide 502, and the optical waveguide 504-3 is input from the port 1 and 9/10 of the WDM optical signal (main optical signal) is the slab waveguide 506, array. It is connected to the slab waveguide 506 at a position where it passes through the waveguide 508 and the slab waveguide 510 and is coupled to the optical waveguide 512 that is a predetermined optical path of the main optical signal. In the optical waveguide 504-4, one-tenth (monitor optical signal) of the WDM optical signal input from the port 1 is transmitted through the slab waveguide 506, the arrayed waveguide 508, and the slab waveguide 510. The slab waveguide 506 is connected at a position where it is coupled to the optical waveguide 514 which is an optical path.

  With the above configuration, in the optical circuit of this reference example, the WDM optical signal input from the optical waveguide 502 is branched into the main optical signal and the monitor optical signal in the directional coupler 504. The main optical signal is input to the arrayed waveguide 508 via the optical waveguide 504-3 and the slab waveguide 506, and wavelength-separated in the arrayed waveguide 508. Each optical signal wavelength-separated from the main optical signal is coupled to the optical waveguide 512 by the slab waveguide 510 and output. On the other hand, the monitor optical signal is input to the arrayed waveguide 508 via the optical waveguide 504-4 and the slab waveguide 506, and wavelength-separated in the arrayed waveguide 508. Each optical signal wavelength-separated from the monitor optical signal is coupled to the optical waveguide 514 by the slab waveguide 510 and output. Therefore, the DEMUX can be configured using the optical circuit of this reference example as one element.

  As described above, it is possible to provide an optical circuit in which additional elements or additional members for extracting a monitor optical signal are reduced. Further, it is possible to provide an optical circuit that extracts 0th-order diffracted light instead of high-order diffracted light as monitor light.

  Next, a second reference example of the present invention will be described with reference to FIG. FIG. 5 is a diagram showing a schematic configuration of an optical circuit 500 of this reference example and a schematic configuration of a part of an optical signal processing apparatus 900 using the same. The optical circuit 500 of this reference example outputs each optical signal obtained by wavelength-separating a part of the input WDM optical signal as a main optical signal, and each wavelength-separated part of the remaining part of the input WDM optical signal. This is an optical circuit capable of outputting signal light as a monitor light signal. The optical signal processing apparatus 900 of this reference example is an optical signal processing apparatus that monitors the monitor optical signal output from the optical waveguide circuit 500 and performs signal processing on the main signal output from the optical waveguide circuit 500.

  The optical circuit 500 of this reference example can be used as a DEMUX unit in the optical signal processing device illustrated in FIG.

  The optical signal processing apparatus 900 of this reference example shown in FIG. 5 includes an arrayed waveguide connected to a 4-port directional coupler 504, a slab waveguide 506, and a slab waveguide 506 that branch incident light at a predetermined ratio. 508, a cylindrical lens 902 and a condenser lens 904 through which a main light signal and a monitor light signal from the substrate 501 are transmitted, a photodetector array 908 for detecting the monitor light signal, and a main light signal, respectively. And a signal processing element 906 for processing.

  The terminal A of the arrayed waveguide 508 shown in FIG. 5 corresponds to the terminal A of the arrayed waveguide 508 shown in FIG. 4, and the directional coupler 504, the slab waveguide 506, and the arrayed waveguide 508 manufactured on the substrate 501. Is the same as FIG. The optical circuit 500 of the present reference example shown in FIG. 5 includes the light shown in FIG. 4 in that it includes a cylindrical lens 902 and a condenser lens 904 as coupling means B that couples light output from the arrayed waveguide 508 to a predetermined optical path. Different from the circuit 500. That is, the cylindrical lens 902 and the condensing lens 904 act so as to couple each optical signal wavelength-separated from the monitor optical signal to the optical path incident on the photodetector element of the corresponding photodetector array 908, and the main light. Each optical signal wavelength-separated from the signal acts to be coupled to the optical path incident on the corresponding signal processing element 906.

  More specifically, the cylindrical lens 902 acts so that the main optical signal and the monitor optical signal output from the arrayed waveguide 508 at an angle corresponding to the wavelength are incident on the condenser lens 904 without spreading in the y direction.

  The condensing lens 904 functions to condense each of the optical signals demultiplexed from the monitor optical signal onto the corresponding photodetector elements of the photodetector array 908. The condenser lens 904 acts to condense each of the optical signals demultiplexed from the main optical signal onto the corresponding signal processing element 906.

  The photodetector array 908 can be, for example, a photodiode array in which a plurality of photodiodes are arranged in the y direction.

  As the signal processing element 906, a phase control element, an intensity control element, or an optical path conversion element such as a liquid crystal, a piezo, an electro-optic crystal, or a micromirror can be used. The signal processing element 906 can be configured to control a processing amount (for example, a phase shift amount, an attenuation amount, an amplification amount) or the like for the main optical signal based on a detection value from the photodetector array 908.

  With the above configuration, in the signal processing apparatus of this reference example, the WDM optical signal input from the optical waveguide 502 of the optical circuit 500 is branched into the main optical signal and the monitor optical signal in the directional coupler 504. The main optical signal is input to the arrayed waveguide 508 via the optical waveguide 504-3 and the slab waveguide 506, and wavelength-separated in the arrayed waveguide 508. Each optical signal wavelength-separated from the main optical signal is coupled to the optical path to the signal processing element 906 by the cylindrical lens 902 and the condenser lens 904, and is input to the signal processing element 906 to be subjected to processing such as phase shift. On the other hand, the monitor optical signal is input to the arrayed waveguide 508 via the optical waveguide 504-4 and the slab waveguide 506, and wavelength-separated in the arrayed waveguide 508. Each optical signal wavelength-separated from the monitor optical signal is coupled to the optical path to the photodetector array 908 by the cylindrical lens 902 and the condenser lens 904, and the optical signal intensity and phase are detected by the photodetector array 908.

  As described above, it is possible to provide an optical circuit and a signal processing device with fewer additional elements or additional members for extracting a monitor optical signal. Further, it is possible to provide an optical circuit and a signal processing apparatus that extract 0th-order diffracted light instead of high-order diffracted light as monitor light.

  Next, a third reference example of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing a schematic configuration of the optical circuit 500 of this reference example. The optical circuit 500 of this reference example outputs each optical signal obtained by wavelength-separating a part of the input WDM optical signal as a main optical signal, and each wavelength-separated part of the remaining part of the input WDM optical signal. It is an optical circuit that can output signal light as a monitor optical signal, and can be used as a component constituting a DEMUX device.

  The optical circuit 500 of the present reference example shown in FIG. 6 includes a 4-port directional coupler 504, which is fabricated on a substrate 501 and branches incident light at a predetermined ratio, a slab waveguide 506, and a slab guide. And an arrayed waveguide 508 connected to the waveguide 506. Furthermore, the optical circuit of this reference example includes a slab waveguide 510 as a coupling means for coupling a part branched from the optical signal output from the arrayed waveguide 508 and the input WDM optical signal to a predetermined optical path. In the optical circuit of this reference example, the coupling means B is constituted by a slab waveguide 510 fabricated on the same substrate 501 as the substrate on which the arrayed waveguide 508 is fabricated.

  In the optical circuit 500 of this reference example, an optical waveguide 504-4 corresponding to the port 4 of the directional coupler 504 is connected to the slab waveguide 510, and an optical waveguide 514 for outputting a monitor optical signal is provided. It differs from the optical circuit shown in FIG. 4 in that it is connected to the slab waveguide 506.

  When the number of wavelengths of a WDM optical signal multiplexed with optical signals of a plurality of wavelengths input from the optical waveguide 502 is N (integer of 2 or more), the number of optical waveguides 512 and 514 is N.

  The arrayed waveguide 508 has a predetermined optical path length difference, and outputs the WDM signal input from the slab waveguide 506 after wavelength separation. When the bandwidth of a WDM optical signal multiplexed with optical signals of a plurality of wavelengths input from the waveguide 502 is F (Hz), the arrayed waveguide 508 has at least F × (N + 1) / N (Hz). It is configured to have a free spectral region.

  The directional coupler 504 bifurcates and outputs the light input from the optical waveguide 504-1 at a predetermined branching ratio (for example, 9 to 1). For example, in the directional coupler 504, 9/10 of the optical signal input from the port 1 is output to the port 3, and 1/10 of the optical signal input from the port 1 is output to the port 4. Similarly, nine tenths of the optical signal input from port 3 is output to port 1, and one tenth of the optical signal input from port 3 is output to port 2.

  In this reference example, the optical waveguide 504-1 is connected to the optical waveguide 502. In the optical waveguide 504-3, 9/10 of the optical signal input from the port 1 and branched (main optical signal) is the slab waveguide 506. The slab waveguide 506 is connected at a position where it passes through the arrayed waveguide 508 and the slab waveguide 510 and is coupled to the optical waveguide 512 which is a predetermined optical path of the main optical signal. In the optical waveguide 504-4, one-tenth (monitor optical signal) of the WDM optical signal input from the port 1 is transmitted through the slab waveguide 510, the arrayed waveguide 508, and the slab waveguide 506. It is connected to the slab waveguide 510 at a position where it is coupled to the optical waveguide 514 which is an optical path.

  With the above configuration, in the optical circuit of this reference example, the WDM optical signal input from the optical waveguide 502 is branched into the main optical signal and the monitor optical signal in the directional coupler 504. The main optical signal is input to the arrayed waveguide 508 via the optical waveguide 504-3 and the slab waveguide 506, and wavelength-separated in the arrayed waveguide 508. Each optical signal wavelength-separated from the main optical signal is coupled to the optical waveguide 512 by the slab waveguide 510 and output. On the other hand, the monitor optical signal is input to the arrayed waveguide 508 via the optical waveguide 504-4 and the slab waveguide 510, and wavelength-separated in the arrayed waveguide 508. Each optical signal wavelength-separated from the monitor optical signal is coupled to the optical waveguide 514 by the slab waveguide 506 and output. Therefore, the DEMUX can be configured using the optical circuit of this reference example as one element.

  Compared with the optical circuit shown in FIG. 4, the optical circuit of this reference example improves the distribution of the optical waveguides connected to the slab waveguides 506 and 510 and improves the degree of integration on the substrate 501. In the optical circuit of this reference example, since the traveling directions of the main optical signal and the monitor optical signal in the two slab waveguides and the arrayed waveguide are different, crosstalk between the two signals is reduced.

  As described above, it is possible to provide an optical circuit in which additional elements or additional members for extracting a monitor optical signal are reduced. Further, it is possible to provide an optical circuit that extracts 0th-order diffracted light instead of high-order diffracted light as monitor light.

  Next, a fourth reference example of the present invention will be described with reference to FIG. FIG. 7 is a diagram showing a schematic configuration of an optical circuit 500 of the present reference example and a schematic configuration of a part of an optical signal processing apparatus 900 using the optical circuit 500. The optical circuit 500 of this reference example outputs each optical signal obtained by wavelength-separating a part of the input WDM optical signal as a main optical signal, and each wavelength-separated part of the remaining part of the input WDM optical signal. This is an optical circuit capable of outputting signal light as a monitor light signal. The optical signal processing apparatus 900 of this reference example is an optical signal processing apparatus that monitors the monitor optical signal output from the optical waveguide circuit 500 and performs signal processing on the main signal output from the optical waveguide circuit 500.

  The optical circuit 500 of this reference example can be used as a DEMUX unit in the optical signal processing device illustrated in FIG.

  The optical signal processing apparatus 900 of this reference example shown in FIG. 7 includes an arrayed waveguide connected to a 4-port directional coupler 504, a slab waveguide 506, and a slab waveguide 506 that branch incident light at a predetermined ratio. A substrate 501 on which 508 is manufactured, a cylindrical lens 902 and a condenser lens 904 through which a main light signal and a monitor light signal from the substrate 501 are transmitted, and a photodetector array (not shown) for detecting the monitor light signal, And a signal processing element 906 for processing the main optical signal. The terminal A of the arrayed waveguide 508 shown in FIG. 7 corresponds to the terminal A of the arrayed waveguide 508 shown in FIG. 6, and the directional coupler 504, the slab waveguide 506, and the arrayed waveguide 508 manufactured on the substrate 501. Is the same as FIG.

  The optical circuit 500 of this reference example shown in FIG. 7 couples an optical signal output from the arrayed waveguide 508 (each optical signal wavelength-separated from the main optical signal) to a predetermined optical path, and from the directional coupler 504. 6 is different from the optical circuit 500 shown in FIG. 6 in that it includes a cylindrical lens 902 and a condenser lens 904 as coupling means B for coupling the output monitor optical signal to a predetermined optical path. That is, the cylindrical lens 902 and the condensing lens 904 act so as to couple each optical signal wavelength-separated from the monitor optical signal to an optical path incident on a photodetector element of a corresponding photodetector array (not shown), In addition, each optical signal wavelength-separated from the main optical signal acts to be coupled to the optical path incident on the corresponding signal processing element 906.

  In addition, the light output from the optical waveguide 504-4 corresponding to the port 4 of the directional coupler 504 is coupled to the arrayed waveguide 508 via the condenser lens 904 and the cylindrical lens 902 constituting the condenser means B. 6 is different from the optical circuit shown in FIG. 6 in that a fiber collimator 910 is provided.

  The monitor optical signal output from the optical waveguide 514 has its optical signal intensity and phase detected by a photodetector array (not shown) (for example, a photodiode array in which a plurality of photodiodes are arranged in the y direction).

  As the signal processing element 906, a phase control element, an intensity control element, or an optical path conversion element such as a liquid crystal, a piezo, an electro-optic crystal, or a micromirror can be used. The signal processing element 906 is configured to control a processing amount (for example, a phase shift amount, an attenuation amount, an amplification amount) or the like for the main optical signal based on a detection value from a photodetector array (not shown). Can do.

  With the above configuration, in the signal processing apparatus of this reference example, the WDM optical signal input from the optical waveguide 502 of the optical circuit 500 is branched into the main optical signal and the monitor optical signal in the directional coupler 504. The main optical signal is input to the arrayed waveguide 508 via the optical waveguide 504-3 and the slab waveguide 506, and wavelength-separated in the arrayed waveguide 508. Each optical signal wavelength-separated from the main optical signal is coupled to the optical path to the signal processing element 906 by the cylindrical lens 902 and the condenser lens 904, and is input to the signal processing element 906 to be subjected to processing such as phase shift. On the other hand, the monitor optical signal is input to the arrayed waveguide 508 via the optical waveguide 504-4, the condenser lens 904, and the cylindrical lens 902, and is wavelength-separated in the arrayed waveguide 508. Each optical signal wavelength-separated from the monitor optical signal is coupled to the optical waveguide 514 by the slab waveguide 506 and output. The optical signal intensity and phase of each optical signal output from the optical waveguide 514 is detected by a photodetector array (not shown).

  As described above, it is possible to provide an optical circuit and a signal processing device with fewer additional elements or additional members for extracting a monitor optical signal. Further, it is possible to provide an optical circuit and a signal processing apparatus that extract 0th-order diffracted light instead of high-order diffracted light as monitor light.

  Further, in the optical circuit of this reference example, crosstalk between the main optical signal and the monitor optical signal is reduced as compared with the optical circuit shown in FIG.

  In the case of configuring an optical signal processing device functioning as a wavelength selective switch as shown in FIG. 18, there arises a problem that the arrangement of a plurality of fiber collimators 910 interfere with each other. In such a case, as shown in FIG. 20, the problem can be solved by disposing the fiber collimator 910 in the y direction with respect to the signal processing element 906 as a reference. 20A is a plan view of the optical signal processing device, and FIG. 20B is a cross-sectional view of the optical signal processing device. As shown in FIG. 20, in the optical signal processing device, by using a part of the condensing lens 904 as a cylindrical lens 918, the fiber collimator 910 can be arranged shifted in the y direction.

Example 1
Next, a first embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram showing a schematic configuration of the optical circuit 500 of the present embodiment. The optical circuit 500 according to this embodiment outputs a part of a WDM optical signal obtained by wavelength combining optical signals having a plurality of input wavelengths as a main optical signal and is wavelength-separated from the other part of the WDM optical signal. It is an optical circuit that can extract a part of each signal light as a monitor optical signal, and can be used as a component constituting a MUX device.

  The optical circuit 500 of the present embodiment shown in FIG. 8 includes a 4-port directional coupler 504, which is fabricated on a substrate 501 and branches incident light at a predetermined ratio, a slab waveguide 506, and a slab guide. And an arrayed waveguide 508 connected to the waveguide 506. Furthermore, the optical circuit of this embodiment includes a slab waveguide 510 as a coupling means for coupling the optical signal input from the optical waveguide 512 and the optical signal output from the directional coupler 504 to a predetermined optical path. In the optical circuit of this embodiment, the coupling means B is constituted by a slab waveguide 510 fabricated on the same substrate 501 as the substrate on which the arrayed waveguide 508 is fabricated.

  Further, the optical circuit 500 of this embodiment includes an optical waveguide 502 for outputting a main optical signal, and an optical waveguide 514 for outputting a monitor optical signal. Optical waveguides 512 and 514 are connected to slab waveguides 510 and 506, respectively.

  In the optical circuit 500 of the present embodiment, the directional coupler 504 splits the light input from the port 3 into two at a predetermined branching ratio (for example, 9 bodies 1) and outputs the branched light. For example, in the directional coupler 504, 9/10 of the optical signal input from the port 3 is output to the port 1, and 1/10 of the optical signal input from the port 3 is output to the port 2.

  The optical waveguide 504-2 corresponding to the port 2 is connected to the slab waveguide 510, and the optical waveguide 504-1 corresponding to the port 1 of the directional coupler 504 is connected to the optical waveguide 502.

  When the number of wavelengths of the optical signal input from the optical waveguide 512 is N (integer of 2 or more), the number of optical waveguides 512 and 514 is N.

  The arrayed waveguide 508 has a predetermined optical path length difference, synthesizes the optical signals of a plurality of wavelengths input from the slab waveguide 510, outputs a WDM signal, and is input from the slab waveguide 510. The WDM optical signal is wavelength-separated and output.

  When the bandwidth of a WDM optical signal multiplexed with optical signals of a plurality of wavelengths input from the optical waveguide 512 is F (Hz), the arrayed waveguide 508 has at least F × (N + 1) / N (Hz). It is configured to have a free spectral region.

  In the optical circuit 500 of this embodiment, the optical waveguide 504-3 of the directional coupler 504 is connected to the slab waveguide 506 at a position where a WDM optical signal is output. The optical waveguide 504-1 is connected to the optical waveguide 502, and outputs 9/10 (main optical signal) of the branched WDM optical signal input from the port 3. In the optical waveguide 504-2, one-tenth (monitor optical signal) of the WDM optical signal input from the port 3 and branched is transmitted through the slab waveguide 510, the arrayed waveguide 508, and the slab waveguide 506, and the monitor optical signal is transmitted. Is connected to the slab waveguide 510 at a position where it is coupled to the optical waveguide 514 which is a predetermined optical path.

  With the above configuration, in the optical circuit of the present embodiment, the optical signals of a plurality of wavelengths input from the optical waveguide 512 are wavelength-synthesized in the arrayed waveguide 508. The wavelength-synthesized WDM optical signal is branched by the directional coupler 504 into a main optical signal and a monitor optical signal. The main optical signal is output from the optical waveguide 502. The monitor optical signal is wavelength-separated in the arrayed waveguide 508. Each optical signal wavelength-separated from the monitor optical signal is output from the optical waveguide 514. Therefore, the MUX can be configured using the optical circuit of this embodiment as one element.

  As described above, it is possible to provide an optical circuit in which additional elements or additional members for extracting a monitor optical signal are reduced. Further, it is possible to provide an optical circuit that extracts 0th-order diffracted light instead of high-order diffracted light as monitor light.

(Example 2)
Next, a second embodiment will be described with reference to FIG. FIG. 9 is a diagram showing a schematic configuration of an optical circuit 500 of this embodiment and an optical signal processing apparatus 900 using the same. The optical circuit 500 according to the present embodiment outputs a part of a WDM optical signal synthesized by inputting an optical signal having a plurality of wavelengths as a main optical signal and is wavelength-separated from the other part of the WDM optical signal. It is an optical circuit that can extract a part of each signal light as a monitor optical signal, and can be used as a component constituting a MUX device. Further, the optical signal processing apparatus 900 of this embodiment combines the wavelengths of the optical signals having a plurality of wavelengths subjected to the signal processing by the signal processing element 906 in the optical waveguide circuit 500 and outputs them as a WDM optical signal, and also the WDM optical signal. Is an optical signal processing apparatus that monitors an optical signal wavelength-separated from a part of the optical signal as a monitor optical signal.

  The optical circuit 500 of this embodiment can be used as a MUX unit in the optical signal processing apparatus illustrated in FIG.

  The optical signal processing apparatus 900 of the present embodiment shown in FIG. 9 includes an arrayed waveguide connected to a 4-port directional coupler 504, a slab waveguide 506, and a slab waveguide 506 that branch incident light at a predetermined ratio. 508, a signal processing element 906 for processing an optical signal, a cylindrical lens 902 through which an optical signal having a plurality of wavelengths from the signal processing element 906 and a monitor optical signal from the directional coupler 504 are transmitted. And a condensing lens 904 and a photodetector array (not shown) for detecting a monitor light signal.

  The cylindrical lens 902 and the condensing lens 904 constitute coupling means B that couples light from the waveguide 504-2, which is a predetermined optical path of the monitor optical signal, to the arrayed waveguide (508).

  The terminal A of the arrayed waveguide 508 shown in FIG. 9 corresponds to the terminal A of the arrayed waveguide 508 shown in FIG.

  In the optical circuit 500 of this embodiment, the light output from the optical waveguide 504-2 corresponding to the port 2 of the directional coupler 504 is arrayed via the condensing lens 904 and the cylindrical lens 902 constituting the condensing means B. 5 is different from the optical circuit shown in FIG. 5 in that a fiber collimator 910 for coupling to the waveguide 508 is provided and an optical waveguide 514 for outputting a monitor optical signal is connected to the slab waveguide 506. Further, the optical signal subjected to signal processing by the signal processing element 906 is input from the arrayed waveguide 508 via the condenser lens 904 and the cylindrical lens 902, and the main optical signal corresponds to the port 1 of the directional coupler 504. It is different from the optical circuit shown in FIG. 7 in that it is output from the optical waveguide 502 connected to the optical waveguide 504-1.

  When the number of wavelengths of a WDM optical signal multiplexed with optical signals of a plurality of wavelengths input through the cylindrical lens 902 and the condenser lens 904 is N (integer of 2 or more), the number of the optical waveguides 514 is N. It becomes.

  The arrayed waveguide 508 has a predetermined optical path length difference, and combines the optical signals of a plurality of wavelengths input through the cylindrical lens 902 and the condenser lens 904, and outputs the resultant as a WDM optical signal, and The WDM optical signal input through the cylindrical lens 902 and the condenser lens 904 is wavelength-separated and output. When the bandwidth of a WDM optical signal in which optical signals of a plurality of wavelengths input through the cylindrical lens 902 and the condenser lens 904 are multiplexed is F (Hz), the arrayed waveguide 508 has at least F × (N + 1). ) / N (Hz) free spectral region.

  In the optical circuit 500 of this embodiment, the optical waveguide 504-3 of the directional coupler 504 is connected to the slab waveguide 506, and the directional coupler 504 receives a WDM optical signal input from the optical waveguide 504-3 as a predetermined signal. Two branches are output at a branching ratio (for example, 9 to 1). Therefore, the optical waveguide 504-3 is connected to the slab waveguide 506 at a position where the WDM optical signal is output. The optical waveguide 504-1 is connected to the optical waveguide 502, and outputs 9/10 (main optical signal) of the branched WDM optical signal input from the port 3. The optical waveguide 504-2 is connected to an optical waveguide (for example, an optical fiber) that connects one-tenth (monitor optical signal) of the WDM optical signal input from the port 3 and branched to the fiber collimator 910. The fiber collimator 910 includes a condensing lens 904 and a condensing lens 904 disposed at a position where the monitor optical signal passes through the arrayed waveguide 508 and the slab waveguide 506 and is coupled to the optical waveguide 514 which is a predetermined optical path of the monitor optical signal. It is arranged at a position where the cylindrical lens 902 is incident.

  With the above configuration, the optical circuit of the present embodiment outputs, from the optical waveguide 502, a WDM optical signal obtained by combining the optical signals of a plurality of wavelengths subjected to signal processing by the signal processing device 906 as a main optical signal. Each optical signal wavelength-separated from a part of the WDM optical signal is output from the optical waveguide 514 as a monitor optical signal. Therefore, the MUX can be configured by using the optical circuit of this embodiment as one element, or can be used as one element of the optical signal processing apparatus.

  As described above, it is possible to provide an optical circuit in which additional elements or additional members for extracting a monitor optical signal are reduced. Further, it is possible to provide an optical circuit that extracts 0th-order diffracted light instead of high-order diffracted light as monitor light.

  An optical signal processing device that functions as a wavelength selective switch can be configured by using a plurality of optical circuits 500 of this embodiment to configure the MUX unit in the optical signal processing device illustrated in FIG.

  FIG. 18A is a plan view of an optical signal processing device functioning as a wavelength selective switch, and FIG. 18B is a cross-sectional view. By using a liquid crystal element and a birefringent crystal element as the signal processing element 906, the optical signal can be routed in the y direction, and a desired optical signal of the optical circuit 500 stacked in the y direction can be switched. The same applies to the following embodiments.

(Example 3)
Next, a third embodiment will be described with reference to FIG. FIG. 10 is a diagram showing a schematic configuration of the optical circuit 500 of the present embodiment. The optical circuit 500 of this embodiment inputs a plurality of wavelengths of optical signals and outputs a wavelength-synthesized WDM optical signal as a main optical signal, and monitors each signal light by wavelength-separating a part of the WDM optical signal. It is an optical circuit that can be taken out as an optical signal, and can be used as a component constituting a MUX device.

  The optical circuit 500 of the present embodiment shown in FIG. 10 includes a 4-port directional coupler 504, which is fabricated on a substrate 501 and branches incident light at a predetermined ratio, a slab waveguide 506, and a slab guide. And an arrayed waveguide 508 connected to the waveguide 506. Furthermore, the optical circuit of the present embodiment couples a plurality of optical signals input from the input waveguide 512 to the arrayed waveguide 508 which is a predetermined optical path, and outputs the optical signal output from the arrayed waveguide 508 through the predetermined optical path. A slab waveguide 510 is provided as a coupling means for coupling to a certain optical waveguide 514. The coupling means B is constituted by a slab waveguide 510 manufactured on the same substrate 501 as the substrate on which the arrayed waveguide 508 is manufactured.

  The optical circuit 500 according to the present embodiment includes an optical waveguide 512 for inputting an optical signal, an optical waveguide 502 for outputting a main optical signal, and an optical waveguide 514 for outputting a monitor optical signal. . Optical waveguides 512 and 514 are each connected to slab waveguide 510. When the number of wavelengths of a WDM optical signal in which optical signals of a plurality of wavelengths input from the optical waveguide 512 are multiplexed is N (integer of 2 or more), the number of optical waveguides 512 and 514 is N.

  The arrayed waveguide 508 has a predetermined optical path length difference, and synthesizes and outputs optical signals of a plurality of wavelengths input from the optical waveguide 512, and outputs the WDM signal input from the slab waveguide 506. Outputs after wavelength separation. When the bandwidth of a WDM optical signal in which optical signals having a plurality of wavelengths input from the waveguide 512 are multiplexed is F (Hz), the arrayed waveguide 508 has a free spectral region of at least 2 F (Hz). It is configured.

  The optical circuit 500 of this embodiment shown in FIG. 10 corresponds to the point where the optical signal is input from the optical waveguide 512, the point where the main optical signal is output from the optical waveguide 502, and the port 2 of the directional coupler 504. 4 is different from the optical circuit shown in FIG. 4 in that the optical waveguide 504-2 is connected to the slab waveguide 506.

  In the optical circuit of the present embodiment, the optical waveguide 512 is coupled to the arrayed waveguide 508 by the slab waveguide 510 to combine the optical signals having a plurality of wavelengths, and synthesizes the wavelength to pass through the slab waveguide 506 as a WDM optical signal. The slab waveguide 510 is connected to the optical waveguide 504-3 corresponding to the port 3 of the directional coupler.

  The directional coupler 504 bifurcates and outputs the optical signal input to the port 3 at a predetermined branching ratio (for example, 9 to 1). The optical waveguide 504-3 corresponding to the port 3 is connected to the slab waveguide 506 at a position where the WDM optical signal output from the slab waveguide 506 is input. The optical waveguide 504-1 connected to the optical waveguide 502 outputs 9/10 (main optical signal) of the optical signal input from the port 3 and branched. In the optical waveguide 504-2 corresponding to the port 2, one-tenth (monitor optical signal) of the optical signal input from the port 3 and branched is transmitted through the slab waveguide 506, the arrayed waveguide 508, and the slab waveguide 510. The slab waveguide 506 is connected to the optical waveguide 514 that is a predetermined optical path of the monitor optical signal.

  With the above configuration, the optical circuit of the present embodiment wavelength-synthesizes optical signals of a plurality of wavelengths input from the optical waveguide 512, and outputs a WDM optical signal as a part of the main optical signal from the optical waveguide 512. The other part of the main optical signal is wavelength-separated and the corresponding monitor optical signal is output from the optical waveguide 514. Therefore, the MUX can be configured using the optical circuit of this embodiment as one element.

  As described above, it is possible to provide an optical circuit in which additional elements or additional members for extracting a monitor optical signal are reduced. Further, it is possible to provide an optical circuit that extracts 0th-order diffracted light instead of high-order diffracted light as monitor light. In the optical circuit of this embodiment, the crosstalk between the main optical signal and the monitor optical signal is reduced.

  Next, a fourth embodiment will be described with reference to FIG. FIG. 11 is a diagram showing a schematic configuration of an optical circuit 500 of the present embodiment and an optical signal processing apparatus 900 using the same. The optical circuit 500 of this embodiment inputs a plurality of wavelengths of optical signals and outputs a wavelength-synthesized WDM optical signal as a main optical signal, and monitors each signal light by wavelength-separating a part of the WDM optical signal. It is an optical circuit that can be taken out as an optical signal, and can be used as a component constituting a MUX device. The optical signal processing apparatus 900 according to the present embodiment monitors the monitor optical signal output from the optical waveguide circuit 500, and performs signal processing on the optical signals of a plurality of wavelengths input to the optical waveguide circuit 500 by the signal processing element 906. An optical signal processing device.

  The optical circuit 500 of this embodiment can be used as a MUX unit in the optical signal processing apparatus illustrated in FIG.

  An optical signal processing apparatus 900 of this embodiment shown in FIG. 11 includes a signal processing element 906 that processes an input optical signal, a 4-port directional coupler 504 that branches incident light at a predetermined ratio, and a slab waveguide. 506 and the substrate 501 on which the arrayed waveguide 508 connected to the slab waveguide 506 is manufactured, and the monitor optical signal from the substrate 501 and the optical signals of a plurality of wavelengths subjected to signal processing by the signal processing device are transmitted. A cylindrical lens 902 and a condenser lens 904, and a photodetector array 908 for detecting a monitor light signal are provided. The terminal A of the arrayed waveguide 508 shown in FIG. 11 corresponds to the terminal A of the arrayed waveguide 508 shown in FIG.

  In the optical circuit 500 of this embodiment shown in FIG. 11, the cylindrical lens 902 and the condensing lens 904 couple a plurality of optical signals subjected to signal processing by the signal processing element 906 to an arrayed waveguide 508 which is a predetermined optical path. And a coupling means B that couples the monitor optical signal output from the arrayed waveguide 508 to a predetermined optical path incident on the photodetector array 908.

  Further, in the optical circuit 500 shown in FIG. 11, the optical signals of a plurality of wavelengths subjected to signal processing in the signal processing element 906 are input to the arrayed waveguide 508 via the condenser lens 904 and the cylindrical lens 902, 5 differs from the optical circuit shown in FIG. 5 in that the main optical signal is output from the optical waveguide 502 and the optical waveguide 504-2 corresponding to the port 2 of the directional coupler 504 is connected to the slab waveguide 506. .

  The photodetector array 908 can be, for example, a photodiode array in which a plurality of photodiodes are arranged in the y direction.

  As the signal processing element 906, a phase control element, an intensity control element, or an optical path conversion element such as a liquid crystal, a piezo, an electro-optic crystal, or a micromirror can be used. The signal processing element 906 can be configured to control the amount of processing for the main optical signal, that is, the amount of phase shift, based on the detection value from the photodetector array 908.

  With the above configuration, the optical signal processing apparatus 900 according to the present embodiment performs signal processing on the input optical signals having a plurality of wavelengths in the signal processing element 906, and then synthesizes the wavelength into a WDM optical signal in the optical circuit 500, The optical coupler 504 branches the main optical signal and the monitor optical signal at a ratio of 9 to 1, and the array optical waveguide 508 separates the wavelength of the monitor optical signal. The wavelength-synthesized main optical signal is output from the optical waveguide 502. On the other hand, the wavelength-separated monitor optical signal is coupled to the optical path to the photodetector array 908, and the optical signal intensity and phase are detected by the photodetector array 908.

  As described above, it is possible to provide an optical circuit and a signal processing device with fewer additional elements or additional members for taking out a monitor optical signal signal. Further, it is possible to provide an optical circuit and a signal processing apparatus that extract 0th-order diffracted light instead of high-order diffracted light as monitor light.

  When an optical signal processing device functioning as a wavelength selective switch as shown in FIG. 18 is configured, there arises a problem that the arrangement of the plurality of photodetector arrays 908 interfere with each other. In such a case, as shown in FIG. 19, the problem can be solved by disposing the photodetector array 908 in the y direction with reference to the signal processing element 906. FIG. 19A is a plan view of the optical signal processing device, and FIG. 19B is a cross-sectional view of the optical signal processing device. As shown in FIG. 19, in the optical signal processing device, by using a part of the condensing lens 904 as a cylindrical lens 918, the photodetector array 908 can be shifted in the y direction.

(Example 5)
Next, a fifth embodiment will be described with reference to FIG. FIG. 12 is a diagram showing a schematic configuration of the optical circuit 500 of the present embodiment. The optical circuit 500 of the present embodiment is an optical circuit that can wavelength-separate a WDM optical signal and output it as a main optical signal, and extract a part of each wavelength-separated signal light as a monitor optical signal, An optical circuit that inputs optical signals of a plurality of wavelengths and outputs a wavelength-synthesized WDM optical signal as a main optical signal, and can extract a part of the WDM optical signal as a monitor optical signal by wavelength-separating a part of the WDM optical signal. is there. Therefore, the optical waveguide circuit 500 of this embodiment is also an optical circuit that can be used as a component constituting the DEMUX device or the MUX device.

  The optical circuit 500 of the present embodiment shown in FIG. 12 includes a four-port directional coupler 504, which is fabricated on a substrate 501 and branches incident light at a predetermined ratio, a slab waveguide 506, and a slab guide. And an arrayed waveguide 508 connected to the waveguide 506. Further, the optical circuit of the present embodiment couples the plurality of optical signals 1 input from the input / output waveguide 512 to the arrayed waveguide 508 which is a predetermined optical path and outputs the monitor optical signal 1 output from the arrayed waveguide 508. The main optical signal and the monitor optical signal of the optical signal 2 (WDM optical signal) input from the input / output optical waveguide 502 and output from the arrayed waveguide 508 are respectively connected to the optical waveguide 514 which is a predetermined optical path. A slab waveguide 510 serving as a coupling means B coupled to the optical waveguides 512 and 514, which are the optical paths of the first and second optical paths. The coupling means B is constituted by a slab waveguide 510 manufactured on the same substrate 501 as the substrate on which the arrayed waveguide 508 is manufactured.

  The number of wavelengths of optical signals having a plurality of wavelengths input from the optical waveguide 512 or the number of wavelengths of WDM optical signals in which optical signals having a plurality of wavelengths input from the optical waveguide 502 are multiplexed is N (integer of 2 or more). In this case, the number of optical waveguides 512 is N, and the number of optical waveguides 514 is N + 1.

  The arrayed waveguide 508 has a predetermined optical path length difference, and synthesizes and outputs the optical signals 1 having a plurality of wavelengths input from the optical waveguide 512. The arrayed waveguide 508 wavelength-separates and outputs the WDM optical signal (optical signal 2) input from the optical waveguide 502. Further, the arrayed waveguide 508 wavelength-separates the monitor optical signals 1 and 2 (WDM signals) input from the optical waveguides 504-2 and 504-4 corresponding to the ports 2 and 4 of the directional coupler 504, respectively. Output. The arrayed waveguide 508 is configured to have a free spectral region of at least (2N + 1) F / N (Hz) when the bandwidth of the WDM optical signal is F (Hz).

  In the optical circuit of the present embodiment, the optical waveguide 512 is coupled to the arrayed waveguide 508 by the slab waveguide 510 to combine the optical signals having a plurality of wavelengths, and synthesizes the wavelength to pass through the slab waveguide 506 as a WDM optical signal. The slab waveguide 512 is connected to the optical waveguide 504-3 corresponding to the port 3 of the directional coupler.

  The directional coupler 504 bifurcates the optical signal input to the port 1 with a predetermined branching ratio (for example, 9 to 1) and outputs it from the ports 3 and 4, and the optical signal input to the port 3 is predetermined. The output is output from ports 1 and 2 after branching into two at the branching ratio.

  The optical waveguide 504-3 corresponding to the port 3 is at a position where the WDM optical signal output from the slab waveguide 506 is input, and wavelength-separated from the WDM optical signal input to the slab waveguide 506. The optical signal is connected to the slab waveguide 506 at a position where each optical signal is output from the optical waveguide 512.

  The optical waveguide 504-1 is connected to the optical waveguide 502, and outputs 9/10 (main optical signal) of the optical signal input from the port 3 and branched. In the optical waveguide 504-2 corresponding to the port 2, one-tenth (monitor optical signal 1) of the optical signal input from the port 3 and branched is transmitted through the slab waveguide 506, the arrayed waveguide 508, and the slab waveguide 510. Then, it is connected to the slab waveguide 506 at a position where it is coupled to the optical waveguide 514 (for example, the 1st to Nth optical waveguides of N + 1 arranged on the substrate 501) which is a predetermined optical path of the monitor optical signal. Has been. In the optical waveguide 504-4 corresponding to the port 4, one-tenth of the input and branched optical signal input from the port 1 (monitor optical signal 2) is the slab waveguide 506, the arrayed waveguide 508, and the slab waveguide. A slab waveguide at a position that passes through 510 and is coupled to an optical waveguide 514 (for example, the 2nd to N + 1th optical waveguides of N + 1 arrayed on the substrate 501), which is a predetermined optical path of the monitor optical signal 506 is connected.

  With the above configuration, the optical circuit of the present embodiment combines the optical signals of a plurality of wavelengths input from the optical waveguide 512 and outputs a part of the optical signal as a WDM optical signal from the optical waveguide 502 as the main optical signal. The other part of the WDM optical signal is wavelength-separated and the corresponding monitor optical signal is output from the optical waveguide 514. Alternatively, the optical circuit of the present embodiment wavelength-separates a part of a WDM optical signal in which optical signals of a plurality of wavelengths input from the optical waveguide 502 are multiplexed, and outputs the result as a main optical signal from the optical waveguide 512. The other part of the WDM optical signal is wavelength-separated and output from the optical waveguide 514 as a monitor optical signal. Therefore, the MUX and DEMUX can be configured using the optical circuit of this embodiment as one element.

  As described above, it is possible to provide an optical circuit in which additional elements or additional members for extracting a monitor optical signal are reduced. Further, it is possible to provide an optical circuit that extracts 0th-order diffracted light instead of high-order diffracted light as monitor light.

(Example 6)
Next, a sixth embodiment will be described with reference to FIG. FIG. 13 is a diagram showing a schematic configuration of an optical circuit 500 of the present embodiment and an optical signal processing device 900 using the same. The optical circuit 500 according to the present embodiment couples each optical signal obtained by wavelength-separating a part of a WDM optical signal obtained by wavelength synthesis of input optical signals having a plurality of wavelengths, to the signal processing device 906, and the signal processing device 906 performs signal processing. Each processed optical signal is input again, wavelength synthesized and output as the main optical signal, and each optical signal obtained by wavelength-separating another part of the input WDM optical signal can be extracted as a monitor optical signal The optical circuit is an optical circuit that can be used as a component constituting the optical signal processing device. The optical signal processing apparatus 900 according to the present embodiment monitors the monitor optical signal output from the optical waveguide circuit 500, and performs signal processing on the optical signals of a plurality of wavelengths input to the optical waveguide circuit 500 by the signal processing element 906. An optical signal processing device.

  The optical circuit 500 of this embodiment can be used as a DEMUX / MUX unit in the optical signal processing apparatus illustrated in FIG.

  The optical signal processing apparatus 900 of this embodiment shown in FIG. 13 includes a signal processing element 906 that processes an input optical signal, a 4-port directional coupler 504 that branches the input light at a predetermined ratio, and a slab. The substrate 501 on which the arrayed waveguide 508 connected to the waveguide 506 and the slab waveguide 506 is manufactured, the monitor optical signal and the main optical signal from the substrate 501, and signal processing by the signal processing device 906 and reflection by the mirror 912. A cylindrical lens 902 and a condensing lens 904 through which the optical signals having a plurality of wavelengths are transmitted, and a photodetector array 908 that detects the monitor optical signal. The terminal A of the arrayed waveguide 508 shown in FIG. 13 corresponds to the terminal A of the arrayed waveguide 508 shown in FIG.

  In the optical circuit 500 of the present embodiment shown in FIG. 13, the cylindrical lens 902 and the condenser lens 904 send the main optical signal and the monitor optical signal output from the arrayed waveguide 508 to the signal processing element 906 and the photodetector array, respectively. A coupling means B is configured to couple a plurality of optical signals coupled to a predetermined optical path to be incident and subjected to signal processing by the signal processing element 906 to an arrayed waveguide 508 which is a predetermined optical path.

  In the signal processing apparatus 900 shown in FIG. 13, an optical signal and a main optical signal are input / output from the optical waveguide 502 via the circulator 914, and optical signals having a plurality of wavelengths subjected to signal processing in the signal processing element 906 are received. Optical waveguides 504-2 and 504 corresponding to the points reflected by the mirror 912 and input to the arrayed waveguide 508 via the condenser lens 904 and the cylindrical lens 902 and the ports 2 and 4 of the directional coupler 504, respectively. 11 is different from the optical signal processing apparatus shown in FIG. 11 in that 4 is connected to the slab waveguide 506.

  The photodetector array 908 can be, for example, a photodiode array in which a plurality of photodiodes are arranged in the y direction.

  As the signal processing element 906, a phase control element or an intensity control element such as a liquid crystal, a piezo, an electro-optic crystal, or a micromirror can be used. The signal processing element 906 can be configured to control the amount of processing for the main optical signal, that is, the amount of phase shift, based on the detection value from the photodetector array 908.

  With the above configuration, a WDM optical signal obtained by wavelength-multiplexing optical signals of a plurality of wavelengths input to the optical signal processing apparatus 900 of this embodiment is input to the port 1 of the directional coupler 504 and is 9: 1. The main optical signal and the monitor optical signal 1 are branched at a ratio.

  The monitor optical signal 1 is output from the port 4 and input to the arrayed waveguide 508 via the slab waveguide 506. The monitor optical signal 1 is wavelength-separated by the array waveguide 508 and coupled to the optical path to the photodetector array 908, and the optical signal intensity and phase are detected by the photodetector array 908.

  The main optical signal is output from the port 3 of the directional coupler 504, input to the slab waveguide 506, wavelength-separated in the arrayed waveguide 508 and output. Each optical signal wavelength-separated from the main optical signal is condensed at a position corresponding to each wavelength of the signal processing element 906 by a cylindrical lens 902 and a condensing lens 904, and subjected to signal processing such as phase shift, and further a mirror 912. As a result, the optical path is inverted and coupled to the arrayed waveguide 508 via the condenser lens 904 and the cylindrical lens 902 again. The optical signals of the respective wavelengths subjected to the signal processing are wavelength-synthesized in the arrayed waveguide 508, transmitted through the slab waveguide 506, and input to the port 3 of the directional coupler, and nine tenths of them are optical waveguides. 502 and the circulator 914.

  One-tenth of the wavelength-combined optical signal of each wavelength input to the directional coupler port 3 is input to the directional coupler port 2 for slab conduction. The light is transmitted through the waveguide 506, is wavelength-separated in the arrayed waveguide 508, and is coupled to the optical path to the photodetector array 908 as the monitor optical signal 2, and the optical signal intensity and phase are detected in the photodetector array 908.

  When the optical waveguides 504-3 and 504-4 are connected to the slab waveguide 506 at an interval of one channel, the optical signals having the same wavelength of the monitor optical signals 1 and 2 are transmitted through one channel of the photodetector array 908. Each is detected at a position shifted by a minute.

  When the optical waveguides 504-3 and 504-4 are connected to the slab waveguide 506 at an interval corresponding to the WDM signal wavelength band, the optical signals having the same wavelength of the monitor optical signals 1 and 2 are output from the photodetector array 908. Each is detected at a position shifted by the WDM signal wavelength band.

  As described above, it is possible to provide an optical circuit and a signal processing device with fewer additional elements or additional members for taking out a monitor optical signal signal. Further, it is possible to provide an optical circuit and a signal processing apparatus that extract 0th-order diffracted light instead of high-order diffracted light as monitor light.

(Example 7)
Next, a seventh embodiment will be described with reference to FIG. FIG. 14 is a diagram showing a schematic configuration of the optical circuit 500 of the present embodiment. The optical circuit 500 of the present embodiment is an optical circuit that can wavelength-separate a WDM optical signal and output it as a main optical signal, and extract a part of each wavelength-separated signal light as a monitor optical signal, An optical circuit that inputs optical signals of a plurality of wavelengths and outputs a wavelength-synthesized WDM optical signal as a main optical signal, and can extract a part of the WDM optical signal as a monitor optical signal by wavelength-separating a part of the WDM optical signal. is there. Therefore, the optical waveguide circuit 500 of this embodiment is also an optical circuit that can be used as a component constituting the DEMUX device or the MUX device.

  The optical circuit 500 of the present embodiment shown in FIG. 14 includes a 4-port directional coupler 504, which is fabricated on a substrate 501 and branches incident light at a predetermined ratio, a slab waveguide 506, and a slab guide. And an arrayed waveguide 508 connected to the waveguide 506. Further, in the optical circuit of this embodiment, a plurality of optical signals 1 input from the input / output waveguide 512 are coupled to the arrayed waveguide 508 which is a predetermined optical path, and are connected to the ports 2 and 4 of the directional coupler 504. A slab waveguide 510 as a coupling means B for coupling the monitor optical signals 1 and 2 (WDM optical signals) respectively output from the corresponding optical waveguides 504-2 and 504-4 to the arrayed waveguide 508, which is a predetermined optical path, is provided. Prepare. The coupling means B is constituted by a slab waveguide 510 manufactured on the same substrate 501 as the substrate on which the arrayed waveguide 508 is manufactured.

  In the optical circuit 500 of this embodiment, an optical waveguide 514 that outputs a monitor optical signal is connected to the slab waveguide 506.

  The number of wavelengths of optical signals having a plurality of wavelengths input from the optical waveguide 512 or the number of wavelengths of WDM optical signals in which optical signals having a plurality of wavelengths input from the optical waveguide 502 are multiplexed is N (integer of 2 or more). In this case, the number of optical waveguides 512 is N, and the number of optical waveguides 514 is N + 1.

  The arrayed waveguide 508 has a predetermined optical path length difference, and synthesizes and outputs the optical signals 1 having a plurality of wavelengths input from the optical waveguide 512. The arrayed waveguide 508 wavelength-separates and outputs the WDM optical signal (optical signal 2) input from the optical waveguide 502. Further, the arrayed waveguide 508 wavelength-separates the monitor optical signals 1 and 2 (WDM signals) input from the optical waveguides 504-2 and 504-4 corresponding to the ports 2 and 4 of the directional coupler 504, respectively. Output. The arrayed waveguide 508 is configured to have a free spectral region of at least (2N + 1) F / N (Hz) when the bandwidth of the WDM optical signal is F (Hz).

  In the optical circuit of the present embodiment, the optical waveguide 512 is coupled to the arrayed waveguide 508 by the slab waveguide 510 to combine the optical signals having a plurality of wavelengths, and synthesizes the wavelength to pass through the slab waveguide 506 as a WDM optical signal. The slab waveguide 512 is connected to the optical waveguide 504-3 corresponding to the port 3 of the directional coupler.

  The directional coupler 504 bifurcates the optical signal input to the port 1 with a predetermined branching ratio (for example, 9 to 1) and outputs it from the ports 3 and 4, and the optical signal input to the port 3 is predetermined. The output is output from ports 1 and 2 after branching into two at the branching ratio.

  The optical waveguide 504-3 corresponding to the port 3 is a position where the WDM optical signal output from the slab waveguide 506 is input, and the waveguide 504-2 and the waveguide 504-4 are slab waveguides. The optical signal is wavelength-separated from the monitor optical signal 1 or 2 (WDM optical signal) input to 510 and is connected to the slab waveguide 510 at a position where the optical signal is output from the optical waveguide 514.

  The optical waveguide 504-1 is connected to the optical waveguide 502, and outputs 9/10 (main optical signal) of the optical signal input from the port 3 and branched. In the optical waveguide 504-2 corresponding to the port 2, one-tenth of the optical signal input from the port 3 and branched (monitor optical signal 1) is transmitted through the slab waveguide 510, the arrayed waveguide 508, and the slab waveguide 506. Then, it is connected to the slab waveguide 510 at a position where it is coupled to the optical waveguide 514 (for example, the 1st to Nth optical waveguides of N + 1 arranged on the substrate 501) which is a predetermined optical path of the monitor optical signal. Has been.

  The optical waveguide 504-3 corresponding to the port 3 is at a position where the WDM optical signal output from the slab waveguide 506 is input, and 10 of the input optical signal 2 branched from the port 1 is input. The slab waveguide at a position where 9 / (WDM optical signal) passes through the slab waveguide 506, the arrayed waveguide 508 and the slab waveguide 510 and is coupled to the optical waveguide 512 which is a predetermined optical path of the main optical signal. 506 is connected.

  In the optical waveguide 504-4 corresponding to the port 4, one-tenth (monitor optical signal 2) of the input and branched WDM optical signal input from the port 1 is the slab waveguide 510, the arrayed waveguide 508, and the slab waveguide. The slab is guided at a position where it passes through the waveguide 506 and is coupled to the optical waveguide 514 (for example, the 2nd to N + 1th optical waveguides of N + 1 arrayed on the substrate 501) which is a predetermined optical path of the monitor optical signal. It is connected to the waveguide 510.

  With the above configuration, the optical circuit of the present embodiment combines the optical signals of a plurality of wavelengths input from the optical waveguide 512 and outputs a part of the optical signal as a WDM optical signal from the optical waveguide 502 as the main optical signal. The other part of the WDM optical signal is wavelength-separated and the corresponding monitor optical signal is output from the optical waveguide 514. Alternatively, the optical circuit of the present embodiment wavelength-separates a part of a WDM optical signal in which optical signals of a plurality of wavelengths input from the optical waveguide 502 are multiplexed, and outputs the result as a main optical signal from the optical waveguide 512. The other part of the WDM optical signal is wavelength-separated and output from the optical waveguide 514 as a monitor optical signal. Therefore, the MUX and DEMUX can be configured using the optical circuit of this embodiment as one element.

  As described above, it is possible to provide an optical circuit in which additional elements or additional members for extracting a monitor optical signal are reduced. Further, it is possible to provide an optical circuit that extracts 0th-order diffracted light instead of high-order diffracted light as monitor light.

  Further, in the optical circuit of this embodiment, the distribution of the optical waveguides connected to the slab waveguides 506 and 510 is improved and the degree of integration on the substrate 501 is improved as compared with the optical circuit shown in FIG. In the optical circuit of this embodiment, the crosstalk between the main optical signal and the monitor optical signal is reduced.

(Example 8)
Next, an eighth embodiment will be described with reference to FIG. FIG. 15 is a diagram showing a schematic configuration of an optical circuit 500 of the present embodiment and an optical signal processing apparatus 900 using the same. The optical circuit 500 according to the present embodiment couples each optical signal obtained by wavelength-separating a part of a WDM optical signal obtained by wavelength synthesis of input optical signals having a plurality of wavelengths, to the signal processing element 906, and the signal processing element 906 outputs a signal. Each processed optical signal is input again, wavelength synthesized and output as the main optical signal, and each optical signal obtained by wavelength-separating another part of the input WDM optical signal can be extracted as a monitor optical signal The optical circuit is an optical circuit that can be used as a component constituting the optical signal processing device. The optical signal processing apparatus 900 according to the present embodiment monitors the monitor optical signal output from the optical waveguide circuit 500, and performs signal processing on the optical signals of a plurality of wavelengths input to the optical waveguide circuit 500 by the signal processing element 906. An optical signal processing device.

  The optical circuit 500 of this embodiment can be used as a DEMUX / MUX unit in the optical signal processing apparatus illustrated in FIG.

  An optical signal processing apparatus 900 of this embodiment shown in FIG. 15 includes a signal processing element 906 that processes an input optical signal, a 4-port directional coupler 504 that branches the input light at a predetermined ratio, and a slab. The substrate 501 on which the arrayed waveguide 508 connected to the waveguide 506 and the slab waveguide 506 is manufactured, the monitor optical signal and the main optical signal from the substrate 501, and signal processing by the signal processing device 906 and reflection by the mirror 912. A cylindrical lens 902 and a condensing lens 904 through which the optical signals having a plurality of wavelengths are transmitted, and a photodetector array (not shown) for detecting the monitor optical signal. The terminal A of the arrayed waveguide 508 shown in FIG. 15 corresponds to the terminal A of the arrayed waveguide 508 shown in FIG.

  In the optical circuit 500 of the present embodiment shown in FIG. 15, the cylindrical lens 902 and the condensing lens 904 are a predetermined light that enters the main optical signal output from the arrayed waveguide 508 into the signal processing element 906 and the photodetector array, respectively. A plurality of optical signals that are coupled to the optical path and subjected to signal processing by the signal processing element 906 are coupled to the arrayed waveguide 508 that is a predetermined optical path, and the monitor optical signals 1 and 2 branched by the directional coupler 504 Is coupled to the arrayed waveguide 508.

  The optical signal processing apparatus 900 shown in FIG. 15 is configured such that optical waveguides 504-2 and 504-4 corresponding to ports 2 and 4 of the directional coupler 504 are connected to fiber collimators 916 and 910, respectively. 13 is different from the optical signal processing apparatus shown in FIG. 13 in that an optical waveguide 514 that outputs optical signals 1 and 2 is connected to a slab waveguide 506.

  The photodetector array (not shown) can be, for example, a photodiode array in which a plurality of photodiodes are arranged in the y direction, and detects a monitor light signal output from the optical waveguide 514.

  As the signal processing element 906, a phase control element or an intensity control element such as a liquid crystal, a piezo, an electro-optic crystal, or a micromirror can be used. The signal processing element 906 can be configured to control the amount of processing for the main optical signal, that is, the amount of phase shift, based on the detection value from the photodetector array 908.

  With the above configuration, a WDM optical signal obtained by wavelength-multiplexing optical signals of a plurality of wavelengths input to the optical signal processing apparatus 900 of this embodiment is input to the port 1 of the directional coupler 504 and is 9: 1. The main optical signal and the monitor optical signal 1 are branched at a ratio.

  The monitor optical signal 1 is output from the port 4 and input to the arrayed waveguide 508 via the fiber collimator 910, the condenser lens 904, and the cylindrical lens 902. The monitor optical signal 1 is wavelength-separated by the array waveguide 508 and coupled to the optical path to the photodetector array, and the optical signal intensity and phase are detected in the photodetector array.

  The main optical signal is output from the port 3 of the directional coupler 504, input to the slab waveguide 506, wavelength-separated in the arrayed waveguide 508 and output. Each optical signal wavelength-separated from the main optical signal is condensed at a position corresponding to each wavelength of the signal processing element 906 by a cylindrical lens 902 and a condensing lens 904, and subjected to signal processing such as phase shift, and further a mirror 912. As a result, the optical path is inverted and coupled to the arrayed waveguide 508 via the condenser lens 904 and the cylindrical lens 902 again. The optical signals of the respective wavelengths subjected to the signal processing are wavelength-synthesized in the arrayed waveguide 508, transmitted through the slab waveguide 506, and input to the port 3 of the directional coupler, and nine tenths of them are optical waveguides. 502 and the circulator 914.

  One-tenth of the wavelength-combined optical signal of each wavelength that has been subjected to signal processing and input to port 3 of the directional coupler is input to port 2 of the directional coupler and is then used as a fiber collimator. 916, the condenser lens 904, and the cylindrical lens 902 are input to the arrayed waveguide 508, and are wavelength-separated in the arrayed waveguide 508 and coupled to the optical path to the photodetector array as the monitor optical signal 2, and the photodetector The optical signal intensity and phase are detected in the array.

  The fiber collimators 910 and 916 and the condensing lens 904 are arranged so that the monitor optical signals 1 and 21 output from the optical waveguides 504-3 and 504-4 are incident on the arrayed waveguide 508 at an interval of one channel. When the cylindrical lens is arranged, the optical signals having the same wavelength of the monitor optical signals 1 and 2 are detected at positions shifted by one channel of the photodetector array.

  The fiber collimators 910 and 916, the collector optical signals 1 and 2 respectively output from the optical waveguides 504-3 and 504-4 are incident on the arrayed waveguide 508 at an interval corresponding to the wavelength band of the WDM signal light. When the optical lens 904 and the cylindrical lens are arranged, the optical signals having the same wavelength of the monitor optical signals 1 and 2 are detected at positions shifted by the WDM signal light wavelength band of the photodetector array.

  As described above, it is possible to provide an optical circuit and a signal processing device with fewer additional elements or additional members for taking out a monitor optical signal signal. Further, it is possible to provide an optical circuit and a signal processing apparatus that extract 0th-order diffracted light instead of high-order diffracted light as monitor light. In the optical circuit of this embodiment, the crosstalk between the main optical signal and the monitor optical signal is reduced.

DESCRIPTION OF SYMBOLS 500 Optical circuit 501 Board | substrate 502,512,514 Optical waveguide 504 Directional coupler 506,510 Slab waveguide 508 Array waveguide 900 Optical signal processing apparatus 902 Cylindrical lens 904 Condensing lens 906 Signal processing element 908 Photodetector array

Claims (5)

An optical circuit,
An optical branching means each branching input light at a predetermined ratio, a slab waveguide, and an arrayed waveguide having a predetermined optical path length difference connected to the slab waveguide;
Coupling means for coupling light from the arrayed waveguide to a predetermined optical path or coupling light from a predetermined optical path to the arrayed waveguide;
The coupling means couples optical signals of a plurality of wavelengths to the arrayed waveguide;
The arrayed waveguide synthesizes the optical signals of the plurality of wavelengths into a WDM optical signal,
The slab waveguide couples the WDM optical signal to the optical branching means,
The optical branching means branches the WDM optical signal,
The coupling means couples one of the branched WDM optical signals to the arrayed waveguide;
The arrayed waveguide wavelength-separates one of the branched WDM optical signals, and couples the wavelength-separated optical signals to the slab waveguide,
The slab waveguide couples the wavelength-separated optical signals to an optical path different from the optical path where the WDM optical signal is coupled to the optical branching unit ,
The input port of the optical branching means is connected to a position where the 0th-order diffracted light of the WDM optical signal is output in the slab waveguide,
The output port of the optical branching unit to which one of the branched WDM optical signals is coupled is connected to the position of the coupling unit where the zero-order diffracted light of each wavelength-separated optical signal is coupled to the different optical path. An optical circuit characterized by that. An optical circuit,
An optical branching means each branching input light at a predetermined ratio, a slab waveguide, and an arrayed waveguide having a predetermined optical path length difference connected to the slab waveguide;
Coupling means for coupling light from the arrayed waveguide to a predetermined optical path or coupling light from a predetermined optical path to the arrayed waveguide;
The coupling means couples optical signals of a plurality of wavelengths to the arrayed waveguide;
The arrayed waveguide synthesizes the optical signals of the plurality of wavelengths into a WDM optical signal,
The slab waveguide couples the WDM optical signal to the optical branching means,
The optical branching means branches the WDM optical signal,
The slab waveguide couples one of the branched WDM optical signals to the arrayed waveguide,
The arrayed waveguide wavelength-separates one of the branched WDM optical signals, couples the wavelength-separated optical signals to the coupling means,
The coupling means couples the wavelength-separated optical signals to an optical path different from the optical path to which the optical signals of the plurality of wavelengths are input ,
The input port of the optical branching means is connected to a position where the 0th-order diffracted light of the WDM optical signal is output in the slab waveguide,
The output port of the optical branching means to which one of the branched WDM optical signals is coupled is connected to the position of the slab waveguide where the zero-order diffracted light of each wavelength-separated optical signal is coupled to the different optical path. An optical circuit characterized by that.   The said coupling | bonding means is a 2nd slab waveguide connected to the said array waveguide produced on the same board | substrate as the said board | substrate with which the said array waveguide was produced, The claim 1 or 2 characterized by the above-mentioned. The optical circuit described.   The optical circuit according to claim 1, wherein the coupling unit is a spatial optical element. An optical circuit according to claim 4,
An optical signal processing device comprising a light detection means and a signal processing element,
The spatial optical element is
Coupling light from the array waveguide to an optical path that inputs to the signal processing element or coupling light from the signal processing element to an optical path that inputs to the array waveguide;
An optical signal processing apparatus, wherein light from the arrayed waveguide is coupled to an optical path for inputting the light to the light detecting means.

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