Optical signal processing device

Abstract

An optical signal processing device (10) comprises a 1-1th slab waveguide (12A), a 1-2th slab waveguide (12B), a first array waveguide (12C), a connection circuit (13), a 2-1th slab waveguide (14A), a 2-2th slab waveguide (14B), and a second array waveguide (14C). The waveguides (12A) to (12C) constitute a first AWG (12). The waveguides (14A) to (14C) constitute a second AWG (14). The first AWG (12) and the second AWG (14) are connected in tandem by the connection circuit (13). The first AWG (12) and the second AWG (14) intersect at the slab waveguides (12A) and (14B) and at the slab waveguides (12B) and (14A). This configuration reduces the size of the optical signal processing device (10).

Description

[Technical Field]

[0001] The present invention relates to an optical signal processing device in which two AWGs (Arrayed Waveguide Gratings) are connected in tandem. [Background technology]

[0002] As disclosed in Non-Patent Document 1, an optical signal processing device in which two AWGs are connected in tandem is known. In such an optical signal processing device, the AWG at the front stage samples multiple light beams with different wavelengths from an input optical signal, and the AWG at the rear stage multiplexes at least some of the sampled multiple light beams. This sampling and multiplexing process enables an optical signal to be obtained that has a highly rectangular wavelength spectrum in a desired wavelength band. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Christopher Richard Doerr, M. Cappuzzo, L. Gomez, E. Chen, A. Wong-Foy, C. Ho, J. Lam, and K. McGreer, "Planar Lightwave Circuit Eight-Channel CWDM Multiplexer With < 3.9-dB Insertion Loss," J. Lightwave Technol. 23, 62- (2005) Summary of the Invention [Problem to be solved by the invention]

[0004] The optical signal processing device disclosed in Non-Patent Document 1 has two tandemly connected AWGs aligned in a row along the longitudinal direction, which disadvantageously increases its size, particularly its length in the longitudinal direction.

[0005] An object of the present invention is to reduce the size of an optical signal processing device. [Means for solving the problem]

[0006] In order to solve the above problems, an optical signal processing device according to the present invention includes a first AWG, a second AWG, and a connection circuit consisting of a plurality of connection waveguides, which connects the first AWG and the second AWG in tandem, wherein the first AWG has a first end connected to the first slab waveguide, a first-1 slab waveguide connected to the first optical waveguide, and a first-2 slab waveguide connected to the connection circuit, and a second end opposite to the first end connected to the first-2 slab waveguide. the second AWG comprises a 2-1 slab waveguide connected to the connection circuit, a 2-2 slab waveguide connected to a second optical waveguide, and a second waveguide array having a first end connected to the 2-1 slab waveguide and a second end opposite to the first end connected to the 2-2 slab waveguide, wherein the 1-1 slab waveguide and the 2-2 slab waveguide intersect, and the 1-2 slab waveguide and the 2-1 slab waveguide intersect. [Effects of the Invention]

[0007] According to the present invention, the size of the optical signal processing device is reduced. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a configuration diagram of an optical signal processing device according to one embodiment of the present invention. [Figure 2] FIG. 2 is a graph showing an example of the wavelength spectrum of light demultiplexed by tandemly connected AWGs. [Figure 3] FIG. 3 is a diagram comparing the sizes of the optical signal processing device of FIG. 1 and an optical signal processing device of a comparative example. [Figure 4] FIG. 4 is a diagram for explaining a method for setting the optical path lengths of the connection waveguides of the connection circuit to be the same. [Figure 5]FIG. 5 is a diagram for explaining a method for setting the optical path lengths of the connection waveguides of the connection circuit to be the same. [Figure 6] FIG. 6 is a diagram for explaining a method for setting the optical path lengths of the connection waveguides of the connection circuit to be the same. [Figure 7] FIG. 7 is a diagram for explaining a method for setting the optical path lengths of the connection waveguides of the connection circuit to be the same. [Figure 8] FIG. 8 is a table showing various parameters when the optical path lengths of the connection waveguides of the connection circuit are set to be the same. DETAILED DESCRIPTION OF THE INVENTION

[0009] An optical signal processing device 10 according to an embodiment of the present invention will be described below with reference to the drawings. First, an overview of the optical signal processing device 10 will be described, and then the optical signal processing device 10 will be described in detail.

[0010] As shown in Fig. 1, an optical signal processing device 10 according to one embodiment of the present invention includes an input waveguide 11, a 1-1 slab waveguide 12A, a 1-2 slab waveguide 12B, a first arrayed waveguide 12C, and a connection circuit 13. The optical signal processing device 10 further includes a 2-1 slab waveguide 14A, a 2-2 slab waveguide 14B, a second arrayed waveguide 14C, and an output waveguide 15. The optical signal processing device 10 is configured as a planar lightwave circuit (PLC) including a silicon or quartz substrate and optical waveguides provided on the substrate that constitute the above-mentioned elements 11 to 15. The optical waveguides are made up of cladding and cores provided on the substrate.

[0011] The waveguides 12A to 12C constitute a first AWG 12, which is a first arrayed waveguide grating. The waveguides 14A to 14C constitute a second AWG 14, which is a second arrayed waveguide grating. The first AWG 12 and the second AWG 14 are connected in tandem by a connection circuit 13. A characteristic configuration of this embodiment is that the first AWG 12 and the second AWG 14 intersect at slab waveguides 12A and 14B and also at slab waveguides 12B and 14A. As a result, the first AWG 12, the second AWG 14, and the connection circuit 13 are formed into an eight-shape as a whole.

[0012] The optical signal processing device 10 will be described in detail below.

[0013] The input waveguide 11 includes a single waveguide into which an optical signal, such as a WDM (Wavelength Division Multiplexing) signal, in which multiplexed light beams each having a different wavelength is input. The optical signal is a signal including light beams with wavelengths λ1 to λ8. The input waveguide 11 may be composed of a plurality of waveguides that propagate the optical signal.

[0014] The first AWG 12 demultiplexes or samples eight light beams with different wavelengths, namely, light beams with wavelength λ1, light beams with wavelength λ2, ..., light beams with wavelength λ8, from the optical signal (input light) input from the input waveguide 11, and outputs the eight sampled light beams to the connection circuit 13. Hereinafter, these eight light beams will also be referred to as light beams λ1 to λ8.

[0015] The 1-1 slab waveguide 12A and the 1-2 slab waveguide 12B of the first AWG 12 are formed in a plate shape. The first arrayed waveguide 12C of the first AWG 12 is composed of a plurality of waveguides of different lengths. One end of the 1-1 slab waveguide 12A is connected to the input waveguide 11, and the other end is connected to one end of the first arrayed waveguide 12C, i.e., one end of each of the plurality of waveguides. The other end of the first arrayed waveguide 12C, i.e., the other end of each of the plurality of waveguides, is connected to one end of the 1-2 slab waveguide 12B. The other end of the 1-2 slab waveguide 12B is connected to one end of the connection circuit 13 (one end of each of connection waveguides 13-1 to 13-8, described later).

[0016] In the first AWG 12, the optical signal from the input waveguide 11 passes through the 1-1 slab waveguide 12A and then through each waveguide of the first arrayed waveguide 12C. The transmitted optical signal is diffracted by the connection between the first arrayed waveguide 12C and the 1-2 slab waveguide 12B, and light λ1 to λ8 is sampled from the optical signal.

[0017] The connection circuit 13 includes eight connection waveguides 13-1 to 13-8 that input the light λ1 to λ8 sampled by the first AWG 12 to the second AWG 14. The eight connection waveguides 13-1 to 13-8 are connected to the other end of the first-second slab waveguide 12B at positions where the light λ1 to λ8 arrive, respectively.

[0018] The second AWG 14 multiplexes at least some of the light beams λ1 to λ8 input from the connection circuit 13 and outputs the multiplexed light to the output waveguide 15. The second AWG 14 separately multiplexes the group of light beams λ1 to λ4 and the group of light beams λ5 to λ8 and outputs the multiplexed light to the output waveguide 15. For this multiplexing, at the connection portion of the connection circuit 13 with the second AWG 14, a gap larger than the gap between the connection waveguides in each group is provided between the group of connection waveguides 13-1 to 13-4 that guide the light beams λ1 to λ4, respectively, and the group of connection waveguides 13-5 to 13-8 that guide the light beams λ5 to λ8, respectively.

[0019] The 2-1 slab waveguide 14A and the 2-2 slab waveguide 14B of the second AWG 14 are formed in a plate shape. The second arrayed waveguide 14C of the second AWG 14 is composed of a plurality of waveguides of different lengths. One end of the 2-1 slab waveguide 14A is connected to the other end of the connection circuit 13 (the other end of each of the connection waveguides 13-1 to 13-8). One end of the second arrayed waveguide 14C, i.e., one end of each of the plurality of waveguides, is connected to the other end of the 2-1 slab waveguide 14A. The other end of the second arrayed waveguide 14C, i.e., the other end of each of the plurality of waveguides, is connected to one end of the 2-2 slab waveguide 14B. The other end of the 2-2 slab waveguide 14B is connected to the output waveguide 15.

[0020] In the second AWG 14, the light λ5 to λ8 from the connection circuit 13 passes through the 2-1 slab waveguide 14A and then through each waveguide of the second arrayed waveguide 14C. The transmitted light λ5 to λ8 is diffracted by the connection portion between the second arrayed waveguide 14C and the 2-2 slab waveguide 14B, thereby multiplexing the light λ1 to λ4 and multiplexing the light λ5 to λ8.

[0021] The output waveguide 15 includes a first output waveguide 15A for guiding the combined light λ1 to λ4 to the outside of the optical signal processing device 10, and a second output waveguide 15B for guiding the combined light λ5 to λ8 to the outside of the optical signal processing device 10. The first output waveguide 15A is connected to the other end of the 2-2 slab waveguide 14B at a position where the light λ1 to λ4 is combined, and receives the light λ1 to λ4. The second output waveguide 15B is connected to the other end of the 2-2 slab waveguide 14B at a position where the light λ5 to λ8 is combined, and receives the light λ5 to λ8. Each of the first output waveguide 15A and the second output waveguide 15B may be composed of a plurality of waveguides.

[0022] As described above, the 1-1 slab waveguide 12A of the first AWG 12 intersects with the 2-2 slab waveguide 14B of the second AWG 14, and both are formed into a plate-like X-shape as a whole. The 1-2 slab waveguide 12B intersects with the 2-1 slab waveguide 14A, and both are formed into a plate-like X-shape as a whole. The slab waveguides 12A and 14B intersect with each other with a sufficient width to prevent crosstalk. The crossing angle is arbitrary. Similarly, the slab waveguides 12B and 14A intersect with each other with a sufficient width to prevent crosstalk, and the crossing angle is arbitrary.

[0023] Due to the above intersection, the first AWG 12 and the second AWG 14 are folded back by the connection circuit 13, and the input waveguide 11 and the output waveguide 15 are arranged on the same side of the first AWG 12 and the second AWG 14. Furthermore, the first AWG 12, the connection circuit, and the second AWG 14 are formed into an eight shape as a whole.

[0024] In the optical signal processing device 10, the first AWG 12 and the second AWG 14 are connected in tandem by the connection circuit 13, and the optical signals output from the waveguides 15A and 15B of the output waveguide 15 have a highly rectangular wavelength spectrum, as shown in FIG. 2. The graph in FIG. 2 shows the transmission intensity of the optical signal transmitted through the optical signal processing device 10 and output from the first output waveguide 15A, for each wavelength. The dashed line graph in FIG. 2 shows the wavelength spectrum when light of a predetermined wavelength is extracted using one AWG. The highly rectangular wavelength spectrum narrows the guard band width, which affects the multiplexing / demultiplexing performance of optical signals. Therefore, the optical signal processing device 10 has high performance as an optical filter that transmits light in a desired wavelength range.

[0025] Furthermore, due to the above-mentioned intersection, the length of the entire optical signal processing device 10 in the X-axis direction (longitudinal direction) is shorter than that of the optical signal processing device 910 according to the comparative example in which the first AWG 12 and the second AWG 14 are arranged in a row, as shown in Fig. 3. Furthermore, the first AWG 12, the connection circuit 13, and the second AWG 14 are formed in an eight-shape as a whole, and if the lengths in the Y-axis direction of the optical signal processing device 10 and the optical signal processing device 910 are the same, the area of ​​the formation region for forming the optical signal processing device is also smaller in the former. For example, assuming L1 = L3 = 10 mm, L2 = 5 mm, and W = 12 in Fig. 3, and ignoring the input waveguide 11 and the output waveguide 15, the area of ​​the formation region for the optical signal processing device 10 is 180 mm 2 The area of ​​the formation region of the optical signal processing device 910 is 300 mm 2 The area of ​​the former is reduced to 60 percent of the area of ​​the latter.

[0026] For the reasons described above, the optical signal processing device 10 has high performance as an optical filter and is small in size (here, length in the X-axis direction and area). When the size of the optical signal processing device 10 is reduced, the size of the chip on which the optical signal processing device 10 is formed also becomes smaller, resulting in a reduction in the cost of the optical signal processing device 10.

[0027] The optical path lengths of the connecting waveguides 13-1 to 13-8 constituting the connecting circuit 13 are preferably equal. The optical path lengths of the connecting waveguides 13-1 to 13-8 may be longer than the optical path length of the reference connecting waveguide mp by an integral multiple (including 1) of the wavelength of the light propagating through that connecting waveguide, except for the optical path length of the shortest connecting waveguide (e.g., connecting waveguide 13-1 propagating light λ1). However, considering that the optical path lengths of the connecting waveguides 13-1 to 13-8 may increase due to changes in ambient temperature, it is desirable that the optical path lengths of the connecting waveguides 13-1 to 13-8 be equal. By making the optical path lengths equal, even if the optical path lengths change due to changes in ambient temperature, the optical path lengths change by the same amount, and the relationship between the optical path lengths remains equal.

[0028] The number of connection waveguides constituting connection circuit 13 may be N, which is an integer equal to or greater than 2. N is set as the number of light beams sampled by first AWG 12. Hereinafter, the first to Nth connection waveguides constituting connection circuit 13 will be referred to as connection waveguides 13-1 to 13-N, respectively.

[0029] An example of a design method for making the optical path lengths of the connection waveguides equal will be described with reference to Figures 4 to 6. In Figures 4 to 6, N=4.

[0030] First, for the j-th (j=1, 2, . . . N) connecting waveguide 13-j, the first straight line S 1j、 The first arc (radius R 1j , central angle θ 1j In order to determine the distance L, the following basic equations (1) and (2) are defined. Here, the distance in the X-axis direction from the center P1 of one end of the first-second slab waveguide 12B of the first AWG 12 on the first arrayed waveguide 12C side to the line Y is defined as L. slab1 The length along the central axis passing through the center P1 of the first-second slab waveguide 12B is f1, and the angle of this central axis with respect to the X axis is β1. Furthermore, the pitch between one end of adjacent connection waveguides 13-j of the connection circuit 13 connected to the first-second slab waveguide 12B is d, and the pitch between one end of adjacent S 1j +R 1j *θ 1j The path difference is Δl 1j Let Δl 1j is assumed to be determined in advance.

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[0031] By solving the simultaneous equations of the above formulas (1) and (2), the first straight line S 1j , the first arc (radius R 1j , central angle θ 1j ) are determined for each of j = 1 to N.

[0032] Also, the sixth straight line S of the above connecting circuit 6j , the sixth arc (radius R 6j , central angle θ 6j ) in Fig. 5. 6j、 The sixth arc (radius R 6j , central angle θ 6j In order to determine the distance L, the following basic equations (3) and (4) are defined. Here, the distance in the X-axis direction from the center P2 of one end of the 2-1 slab waveguide 14A of the second AWG 14 on the second arrayed waveguide 14C side to the line Y is defined as L. slab2 The length along the central axis passing through the center P2 of the 2-1 slab waveguide 14A is f2, and the angle of this central axis with respect to the X axis is β2. Furthermore, the pitch between one ends of the connection waveguides 13-j of the connection circuit 13 connected to the 2-1 slab waveguide 14A is d, and the pitch between the adjacent S 6j +R 6j *θ 6j The path difference is Δl 6j Let Δl 6j is assumed to be determined in advance. g in the formula (4) is g of g numbers described later.

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[0033] Here, the second AWG 14 separately multiplexes a group of light transmitted through the connecting waveguides 13-1 and 13-2 and a group of light transmitted through the connecting waveguides 13-3 and 13-4, and outputs the multiplexed light to waveguides 15A and 15B of the output waveguide 15, respectively. Therefore, at the connection portion of the connecting circuit 13 with the second AWG 14, g connecting waveguides (1 connecting waveguide in this case) are virtually set between the group of connecting waveguides 13-1 and 13-2 and the group of connecting waveguides 13-3 and 13-4, thereby providing a physical distance between them. For this reason, here, the maximum value of J is set to N+g only here.

[0034] By solving the simultaneous equations (3) and (4), the sixth straight line S 6j , the sixth arc (radius R 6j , central angle θ 6j ) are determined. These are determined for each of j=1 to N+g. However, the parameters for the above virtual g connecting waveguides will not be used later, and the sixth arcs of j=N-Q+1+g to N+g are determined for each of the curves C j where Q is the number of connecting waveguides grouped by the above spacing (here, connecting waveguides 13-1 and 13-2, and connecting waveguides 13-3 and 13-4), which is 2 here. If g=1, the sixth circular arc where j=4 here is connected to the subsequent curve C3, and the sixth circular arc where j=5 is connected to the subsequent curve C4. Note that the above equation j= can be changed as appropriate depending on the number of groups of connecting waveguides, etc.

[0035] In this way, by providing g virtual connection waveguides between two adjacent groups of the plurality of groups 13-1 to 13-N of connection waveguides, a larger distance is provided between each group than the distance between connection waveguides within the same group. This allows the optical signals transmitted through each of the plurality of connection waveguides 13-1 to 13-N to be effectively multiplexed separately for each group. g does not have to be an integer, such as 1.5. In this case, for example, g in the above equation j=··· is set to the integer closest to g among integers larger than g (for example, "2" when g=1.5).

[0036] Then, point Y j and point Y′ j Curve C between j Find the point Y'. j is a distance w' in the Y direction from the X axis passing through the intersection of the central axis of the 1-2 slab waveguide 12B and the central axis of the 2-1 slab waveguide 14A. j From the viewpoint of design difficulty, j is the w in Figure 4j It is recommended to set it equal to w j is the intersection point between the X axis and the second line S 2j The distance between point Y′ and point Y′ is j The coordinates of are w′ j (X coordinate is set arbitrarily), point Y j The coordinates of the sixth line S 6j , the sixth arc (radius R 6j , central angle θ 6j ) parameters. From these, point Y j From point Y' j Extends continuously to point Y j and point Y′ j Curve C connecting j Determine the curve C j For example, the curve C can be made up of two circular arcs as shown in Figure 6. j is calculated for each of J=1 to N.

[0037] curve C j is the point Y j and point Y′ j Any curve can be used as long as the optical path length is known, but by defining it with two arcs as shown in Figure 5, the point Y j From point Y' j and R cj If the central angle δ of the arc is determined in advance, it can be calculated using the following formula (5): j is easily found.

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[0038] Then, referring to the design value and size of the optical signal processing device 10, the second straight line S of the connection circuit 13 in FIGS. 2j , W j , w j (=w′ j ) is determined in advance. Furthermore, the second arc (radius R 2j , central angle θ 2j +π / 2), the third line S 3j , the third arc (radius R 3j , central angle θ 3j) is determined in advance. For the sake of simplicity, R 2j =R 5j , R 3j =R 4j , θ 2j =θ 3j =θ 4j =θ 5j Then, the remaining unknown parameters can be derived by solving the simultaneous equations of the following equations (6) to (8). This derivation is performed for each of j=1 to N.

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[0039] Parameters other than those derived above are desirably determined in advance within a range that does not pose a problem in terms of the layout of the connection circuit 13. Specifically, it is desirable to determine these parameters in advance within a range that does not cause problems such as overlapping of adjacent connection waveguides and overlapping of the first-second slab waveguide 12B and the second-first slab waveguide 14A with the connection circuit 13. From the viewpoint of design difficulty, R 2j , R 5j may be determined in advance.

[0040] R 2j , and R 5j When the waveguide is designed with a constant curvature, adjacent connecting waveguides often overlap each other. To ease the design difficulty, we set the R 2j R' 2j and R′ is fixed regardless of j. Tj In this case, multiple curvatures may be used, such as dividing the curvature into R' Tj It is desirable to determine this in advance.

[0041] An example of some of the parameters derived in this manner is shown in FIG.

[0042] In this way, the optical path lengths of the connection waveguides 13-1 to 13-N of the connection circuit 13 can be made the same. In particular, the seven curved portions (the first to sixth arcs and the curved line C) j ) by using a plurality of curved portions, the optical path lengths of the connecting waveguides 13-1 to 13-N can be set to be the same by a relatively easy method.

[0043] The optical path lengths of the connecting waveguides 13-1 to 13-N of the connecting circuit 13 may be made different, and the connecting circuit 13 may have a dispersion compensation function for compensating for the chromatic dispersion of the light propagating through each of the connecting waveguides 13-1 to 13-N. In this case, the right side of the above formula (8) may be defined as in the following formula (9), and various parameters may be set. Here, l1 is the optical path length of the connecting waveguide 13-1 where j=1, and ΔL j is the difference in optical path length between the connection waveguide 13-j and the connection waveguide 13-(j-1) adjacent to the connection waveguide 13-j in the direction where j is subtracted by 1.

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[0044] The above embodiment can be modified in various ways. The optical signal processing device 10 may operate as an optical wavelength multiplexer / demultiplexer in which the traveling direction of light is reversed. The shape of each element (waveguide) constituting the optical signal processing device 10 may be modified as appropriate. The optical path length may be adjusted by making at least some of the connection waveguides 13-1 to 13-N meander. Even when the optical path lengths of the connection waveguides 13-1 to 13-N are different, the connection circuit 13 has multiple curved portions, so that the relationship between the lengths of the optical path lengths can be easily defined. The second AWG 14 may multiplex light of all wavelengths sampled by the first AWG 12 into a single optical signal. Even in this case, light of wavelengths not sampled is removed from the input optical signal, and an output with a highly rectangular wavelength spectrum is obtained.

[0045] Although the optical signal processing device 10 has been described above as a demultiplexer that demultiplexes an input optical signal, the input and output can be reversed based on the principle of reverse optical propagation. That is, the output waveguide 15 may be the input optical waveguide, and the input waveguide 11 may be the output optical waveguide. In this case, the optical signal processing device 10 operates as a multiplexer that multiplexes optical signals input from the waveguides 15A and 15B of the output waveguide 15. Such a multiplexer outputs a multiplexed optical signal with a highly rectangular wavelength spectrum. In this way, the optical signal processing device 10 is also an optical wavelength multiplexer / demultiplexer that can operate as either a demultiplexer or a multiplexer, or both, depending on the installation location.

[0046] The present invention is not limited to the above-described embodiments and modifications. For example, the present invention includes various modifications to the above-described embodiments and modifications that can be understood by a person skilled in the art within the scope of the technical concept of the present invention. The configurations listed in the above-described embodiments and modifications can be combined as appropriate within a range that does not cause contradictions. Furthermore, any of the above-described configurations can be deleted.

[0047] (Addendum) The configurations disclosed in this specification, taking the above-described embodiments and modifications as examples, will be exemplified below. (Appendix 1) a first AWG, a second AWG, and a connection circuit consisting of a plurality of connection waveguides and connecting the first AWG and the second AWG in tandem, wherein the first AWG comprises a 1-1 slab waveguide connected to a first optical waveguide, a 1-2 slab waveguide connected to the connection circuit, and a first arrayed waveguide having a first end connected to the 1-1 slab waveguide and a second end opposite to the first end connected to the 1-2 slab waveguide, the second AWG comprises a 2-1 slab waveguide connected to the connection circuit, a 2-2 slab waveguide connected to a second optical waveguide, and a second waveguide array having a first end connected to the 2-1 slab waveguide and a second end opposite to the first end connected to the 2-2 slab waveguide, wherein the 1-1 slab waveguide and the 2-2 slab waveguide intersect, and the 1-2 slab waveguide and the 2-1 slab waveguide intersect. (Appendix 2) 2. The optical signal processing device according to claim 1, wherein the plurality of connecting waveguides have the same optical path length. (Appendix 3) 3. The optical signal processing device according to claim 2, wherein the connection circuit comprises a plurality of curved portions. (Appendix 4) The optical signal processing device according to claim 1, wherein the plurality of connection waveguides are made up of a first connection waveguide and one or more second connection waveguides different from the first connection waveguide, and the optical path length of each of the one or more second connection waveguides is longer than the optical path length of the first connection waveguide by an integer multiple of the wavelength of light guided by the second connection waveguide. Note that in this case, the connection circuit may include a plurality of curved sections. (Appendix 5) The optical signal processing device according to claim 1, wherein the connection circuit compensates for chromatic dispersion of light propagating through each of the plurality of connection waveguides by varying the optical path length of each of the plurality of connection waveguides. Note that in this case, the connection circuit may include a plurality of curved portions. (Appendix 6) 6. The optical signal processing device according to claim 1, wherein the first AWG, the second AWG, and the connection circuit form an eight-shape as a whole. (Appendix 7) The first AWG is configured to sample a plurality of optical signals having different wavelengths from an input optical signal when the input optical signal is input via the first optical waveguide. The second AWG is configured to multiplex at least some of the plurality of optical signals sampled by the first AWG and output the multiplexed optical signals to the second optical waveguide. The plurality of connection waveguides of the connection circuit are configured to guide the plurality of light beams sampled by the first AWG, respectively, and input the multiple light beams to the second AWG. [Explanation of symbols]

[0048] 10...optical signal processing device, 11...input waveguide, 12...first AWG, 12A...slab waveguide, 12B...slab waveguide, 12C...first arrayed waveguide, 13...connection circuit, 13-1 to 13-8, 13-j, 13-N...connection waveguides, 14...second AWG, 14A...slab waveguide, 14B...slab waveguide, 14C...second arrayed waveguide, 15...output waveguide, 15A...first output waveguide, 15B...second output waveguide, 910...optical signal processing device.

Claims

1. a first AWG; and a second AWG; and a connection circuit including a plurality of connection waveguides for tandemly connecting the first AWG and the second AWG; the first AWG comprises a first-1 slab waveguide connected to a first optical waveguide, a first-2 slab waveguide connected to the connection circuit, and a first arrayed waveguide having a first end connected to the first-1 slab waveguide and a second end opposite to the first end connected to the first-2 slab waveguide; the second AWG comprises a second-1 slab waveguide connected to the connection circuit, a second-2 slab waveguide connected to a second optical waveguide, and a second waveguide array having a first end connected to the second-1 slab waveguide and a second end opposite to the first end connected to the second-2 slab waveguide; the first-1 slab waveguide and the second-2 slab waveguide intersect; the first-2 slab waveguide and the second-1 slab waveguide intersect; one end of each of the plurality of connecting waveguides is directly connected to the first and second slab waveguides; the other end opposite to the one end of each of the plurality of connecting waveguides is directly connected to the second-1 slab waveguide, Each of the plurality of connecting waveguides has a plurality of curved portions and has the same optical path length. Optical signal processing device.

2. the first AWG, the second AWG, and the connection circuit form an eight-shaped configuration as a whole; The optical signal processing device according to claim 1 .

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