Optical circuit

Abstract

The optical loop can improve versatility and user convenience at the same time. An optical circuit is provided with: an optical switching circuit including N * N Mach-Zehnder interferometers arranged in a matrix of N rows and N columns (where N is an integer of 8 or more); a first switching unit that switches objects to be connected to the outside of each of M Mach-Zehnder interferometers among N Mach-Zehnder interferometers included in a first column of a matrix comprising the N * N Mach-Zehnder interferometers, where M is an integer of 1 or more and N or less; and a second switching unit that switches connection objects to the outside of each of L Mach-Zehnder interferometers among the N Mach-Zehnder interferometers included in the Nth column of the matrix, where L is an integer from 1 to N (inclusive).

Description

Technical Field

[0001] This invention relates to optical circuits.

[0002] This application claims priority based on Japanese Patent Application No. 2023-123531, filed in Japan on July 28, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] In recent years, research and development of optical circuits have been ongoing. These optical circuits are used for processing optical signals.

[0004] In this regard, there are known optical switching circuits that maintain the state of the optical signal without photoelectric conversion and efficiently perform the optical signal exchange required for optical communication, optical interconnection and other applications (see Non-Patent Literature 1, 2).

[0005] In addition, as unitary matrix operation loops required for efficient deep learning and other matrix operations using optical signals, Clements-type optical loops and Bell-type optical loops are known (see Non-Patent Literature 3, 4).

[0006] [Existing Technical Documents] [Non-patent literature] Non-patent literature 1: Keijiro Suzuki, et al., "Ultra-compact 8 × 8 strictly-non-blocking Si-wire PILOSS switch," OPTICS EXPRESS, Vol. 22, Issue 4, 24 February 2014, pp. 3887-3894. Non-Patent Literature 2: Ken Tanizawa, et al., "Ultra-compact 32 × 32 strictly-non-blocking Si-wire optical switch with fan-out LGA interposer," OPTICS EXPRESS, Vol. 23, Issue 13, 29 June 2015, pp.17599-17606. Non-patent literature 3: William R. Clements, et al., “Optimal design for universal multiport interferometers,” Optica, Vol. 3, Issue 12, 6 December 2016, pp. 1460-1465. Non-Patent Literature 4: BA Bell, and IA Walmsley., “Further compactifying linear optical unitaries,” APL Photonics, Vol. 6, Issue 7, 13 July 2021, 070804. Summary of the Invention The problem the invention aims to solve Here, optical circuits such as optical switch circuits and unitary matrix operation circuits are mostly used for a single purpose. Therefore, if the user of such an optical circuit wants to change its purpose, the connected objects must also be changed, which can sometimes take a lot of time and effort.

[0007] This disclosure was made with the consideration of such circumstances, and its objective is to provide an optical circuit that can simultaneously improve versatility and user convenience.

[0008] Methods for solving problems According to the scheme disclosed herein, the optical circuit comprises: an optical switching circuit, the optical switching circuit including N×N Mach-Zehnder interferometers configured in an N-row N-column matrix, where N is an integer greater than or equal to 8; a first switching unit, the first switching unit switching the connection pairs of each of M Mach-Zehnder interferometers among the N Mach-Zehnder interferometers included in the first column of the matrix composed of the N×N Mach-Zehnder interferometers with external connections, where M is any integer greater than or equal to 1 and less than N; and a second switching unit, the second switching unit switching the connection pairs of each of L Mach-Zehnder interferometers among the N Mach-Zehnder interferometers included in the Nth column of the matrix with external connections, where L is any integer greater than or equal to 1 and less than N.

[0009] The effects of the invention According to this disclosure, both versatility and user convenience can be improved. Attached Figure Description

[0010] Figure 1 This is a diagram showing an example of the structure of optical loop 1.

[0011] Figure 2 This is a diagram showing an example of optical circuit 1 operating as a PILOSS optical switch circuit, where the PILOSS optical switch circuit outputs eight first optical signals by inputting eight first optical signals.

[0012] Figure 3 This is a diagram showing another example of the state of optical circuit 1 operating as a PILOSS optical switch circuit, where the PILOSS optical switch circuit outputs 8 first optical signals by inputting 8 first optical signals.

[0013] Figure 4 This diagram illustrates an example of 32 first Mach-Zehnder interferometers operating as first unitary matrix operation loops.

[0014] Figure 5 This diagram illustrates an example of 32 second Mach-Zehnder interferometers operating as second unitary matrix operation loops.

[0015] Figure 6 This is a diagram showing an example of an MZI matrix with cross waveguides CS connected to the third and fourth ports of each Mach-Zehnder interferometer.

[0016] Figure 7 This is a diagram showing another example of the structure of optical loop 1.

[0017] Figure 8 It is shown Figure 7The diagram shows an example of optical loop 1 operating as a unitary matrix operation loop for the first unitary matrix operation.

[0018] Figure 9 It is shown Figure 7 The diagram shows an example of optical loop 1 operating as a unitary matrix operation loop for the second unitary matrix operation.

[0019] Figure 10 This is another example of the structure of optical loop 1. Detailed Implementation

[0020] Implementation Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0021] <An Overview of Optical Circuits> First, an overview of the optical circuitry in the implementation method will be provided.

[0022] The optical circuit of the embodiment includes: an optical switching circuit comprising N×N Mach-Zehnder interferometers arranged in an N-row N-column matrix, where N is an integer greater than or equal to 8; a first switching unit that switches the connection of each of M Mach-Zehnder interferometers out of the N Mach-Zehnder interferometers in the first column of the matrix composed of the N×N Mach-Zehnder interferometers with an external connection object, where M is any integer greater than or equal to 1 and less than N; and a second switching unit that switches the connection of each of L Mach-Zehnder interferometers out of the N Mach-Zehnder interferometers in the Nth column of the matrix with an external connection object, where L is any integer greater than or equal to 1 and less than N.

[0023] Therefore, by allowing the user to change the connection object of the optical circuit using the first switching unit and the second switching unit, the application of the optical circuit can be easily changed. As a result, the optical circuit can improve both versatility and user convenience. Furthermore, this application can be represented, for example, by the type of optical signal that is the target of processing by the optical circuit, and the operation of the optical circuit on the optical signal.

[0024] The structure of the optical circuit in the following embodiment will be described in detail.

[0025] <Structure of an optical circuit> The structure of the optical circuit in this embodiment will be described below using optical circuit 1 as an example. Furthermore, in this embodiment, the connection between various components refers to the connection via waveguides that transmit optical signals. For example, in this embodiment, when two Mach-Zehnder interferometers are connected to each other, it means that these two Mach-Zehnder interferometers are connected via waveguides. Similarly, in this embodiment, when a Mach-Zehnder interferometer is connected to an amplitude modulator, it means that the Mach-Zehnder interferometer and the amplitude modulator are connected via waveguides.

[0026] Figure 1 This is a diagram showing an example of the structure of optical loop 1.

[0027] Optical loop 1 is an optical loop that can switch its operation according to its purpose. For example, optical loop 1 can selectively switch between two operations: one is the operation of exchanging optical signals required for optical communication, optical interconnection, etc., and the other is the operation of performing unitary matrix operations using optical signals, according to control from a control device communicatively connected to optical loop 1.

[0028] Here, the control device is an information processing device that controls optical loop 1. Regarding the control device, it can be any device capable of controlling optical loop 1, such as a dedicated information processing device for controlling optical loop 1, a workstation, a desktop PC (Personal Computer), a laptop PC, etc., but is not limited to these. Alternatively, the control device can also be a processor such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array). Therefore, in this embodiment, the description of the control device is omitted.

[0029] Optical circuit 1 includes optical switch circuit 10, first switching unit 11, and second switching unit 12. In addition, optical circuit 1 may also have other circuits, other components, other devices, etc.

[0030] The optical switching circuit 10 is a switching circuit comprising N×N Mach-Zehnder interferometers arranged in an N-row, N-column matrix. Hereinafter, as an example, the case where the optical switching circuit 10 is a PILOSS (Path Independent Insertion Loss) optical switching circuit will be described. Furthermore, the optical switching circuit 10 can be any switching circuit comprising N×N Mach-Zehnder interferometers arranged in an N-row, N-column matrix, or other types of optical switching circuits can be used instead of the PILOSS optical switching circuit. Here, N is an integer of 8 or more. Hereinafter, as an example, the case where N is 8 will be described. Furthermore, in this embodiment, since the Mach-Zehnder interferometer is a known interferometer, detailed descriptions are omitted.

[0031] In this case, such as Figure 1 As shown, the optical switching circuit 10 includes 8×8 Mach-Zehnder interferometers (i.e., 64 Mach-Zehnder interferometers) arranged in an 8x8 matrix. For ease of explanation, the matrix formed by the 8×8 Mach-Zehnder interferometers included in the optical switching circuit 10 will be referred to as the MZI (Mach-Zehnder Interferometer) matrix. Furthermore, for ease of explanation, the direction from the Nth column of the MZI matrix to the first column of the MZI matrix, one of the two directions parallel to each row of the MZI matrix, will be called the first row direction; the direction from the first column of the MZI matrix to the Nth column of the MZI matrix will be called the second row direction; unless it is necessary to distinguish between these two directions, they will be collectively referred to as row directions. Furthermore, for ease of explanation, the direction from the Nth row of the MZI matrix toward the first row of the MZI matrix, which is parallel to each column of the matrix, will be referred to as the first column direction. The direction from the first row of the MZI matrix toward the Nth row of the MZI matrix will be referred to as the second column direction. Unless it is necessary to distinguish between the two directions, they will be referred to as column directions for explanation. Figure 1 The arrows shown represent respectively Figure 1The directions are: first row direction, second row direction, first column direction, and second column direction. For ease of explanation, the port on the first row and first column direction side of the four ports (i.e., the four ports provided in all Mach-Zehnder interferometers capable of optical signal input and output) appearing in this embodiment will be referred to as the first port, and the port on the first row and second column direction side of these four ports will be referred to as the second port. For ease of explanation, the port on the second row and first column direction side of these four ports will be referred to as the third port, and the port on the second row and second column direction side of these four ports will be referred to as the fourth port. Furthermore, for ease of explanation, the eight rows of the MZI matrix will be referred to sequentially from the first column direction towards the second column direction as the first row, second row, third row, fourth row, fifth row, sixth row, seventh row, and eighth row. Furthermore, for ease of explanation, the eight columns of the MZI matrix will be referred to as column 1, column 2, column 3, column 4, column 5, column 6, column 7, and column 8, respectively, from the first row direction towards the second row direction.

[0032] In the following text, for ease of explanation, such as Figure 1 As shown, each of the eight Mach-Zehnder interferometers in the i-th row of the MZI matrix is ​​named Mach-Zehnder interferometer Mi1, Mi2, Mi3, Mi4, Mi5, Mi6, Mi7, and Mi8, respectively, moving from the direction of the first row towards the direction of the second row. Here, i is any integer from 1 to 8. That is, for example, each of the eight Mach-Zehnder interferometers included in the first row of the MZI matrix, from the direction of the first row towards the direction of the second row, is Mach-Zehnder interferometer M11, Mach-Zehnder interferometer M12, Mach-Zehnder interferometer M13, Mach-Zehnder interferometer M14, Mach-Zehnder interferometer M15, Mach-Zehnder interferometer M16, Mach-Zehnder interferometer M17, and Mach-Zehnder interferometer M18. Furthermore, for example, each of the eight Mach-Zehnder interferometers included in the fifth row of the MZI matrix, from the direction of the first row towards the direction of the second row, is Mach-Zehnder interferometer M51, Mach-Zehnder interferometer M52, Mach-Zehnder interferometer M53, Mach-Zehnder interferometer M54, Mach-Zehnder interferometer M55, Mach-Zehnder interferometer M56, Mach-Zehnder interferometer M57, and Mach-Zehnder interferometer M58.

[0033] Furthermore, when i is any one of 1 to 8, the first port and the second port of the Mach-Zehnder interferometer Mi1 are respectively connected to the first switching unit 11. Furthermore, when i is any one of 1 to 8, the third port and the fourth port of the Mach-Zehnder interferometer Mi8 are respectively connected to the second switching unit 12.

[0034] Furthermore, in cases where j is any one of 2 to 8, the first port of the Mach-Zehnder interferometer M1j is connected via a waveguide to the third port of the Mach-Zehnder interferometer M1j-1. For example, the first port of the Mach-Zehnder interferometer M12 is connected via a waveguide to the third port of the Mach-Zehnder interferometer M11.

[0035] Furthermore, in cases where j is any one of 1 to 7, the third port of the Mach-Zehnder interferometer M1j is connected via a waveguide to the first port of the Mach-Zehnder interferometer M1j+1. For example, the third port of the Mach-Zehnder interferometer M17 is connected via a waveguide to the first port of the Mach-Zehnder interferometer M18.

[0036] Additionally, in cases where j is any one of 2 to 8, the second port of the Mach-Zehnder interferometer M8j is connected via a waveguide to the fourth port of the Mach-Zehnder interferometer M8j-1. For example, the second port of the Mach-Zehnder interferometer M82 is connected via a waveguide to the fourth port of the Mach-Zehnder interferometer M81.

[0037] Additionally, in cases where j is any one of 1 to 7, the fourth port of the Mach-Zehnder interferometer M8j is connected via a waveguide to the second port of the Mach-Zehnder interferometer M8j+1. For example, the fourth port of the Mach-Zehnder interferometer M87 is connected via a waveguide to the second port of the Mach-Zehnder interferometer M88.

[0038] Furthermore, when i is any one of 2 to 8 and j is any one of 2 to 8, the first port of the Mach-Zehnder interferometer Mij is connected to the fourth port of the Mach-Zehnder interferometer Mi-1j-1 via a waveguide. For example, the first port of the Mach-Zehnder interferometer M22 is connected to the fourth port of the Mach-Zehnder interferometer M11 via a waveguide.

[0039] Furthermore, in cases where i is any one of 1 to 7 and j is any one of 2 to 8, the second port of the Mach-Zehnder interferometer Mij is connected via a waveguide to the third port of the Mach-Zehnder interferometer Mi+1j-1. For example, the second port of the Mach-Zehnder interferometer M72 is connected via a waveguide to the third port of the Mach-Zehnder interferometer M81.

[0040] Furthermore, in cases where i is any one of 2 to 8 and j is any one of 1 to 7, the third port of the Mach-Zehnder interferometer Mij is connected via a waveguide to the second port of the Mach-Zehnder interferometer Mi-1j+1. For example, the third port of the Mach-Zehnder interferometer M27 is connected via a waveguide to the second port of the Mach-Zehnder interferometer M18.

[0041] Furthermore, in cases where i is any one of 1 to 7 and j is any one of 1 to 7, the fourth port of the Mach-Zehnder interferometer Mij is connected via a waveguide to the first port of the Mach-Zehnder interferometer Mi+1j+1. For example, the fourth port of the Mach-Zehnder interferometer M77 is connected via a waveguide to the first port of the Mach-Zehnder interferometer M88.

[0042] That is, as described above, the optical switching circuit 10 is a PILOSS optical switching circuit. Furthermore, since the PILOSS optical switching circuit is a known circuit, further detailed descriptions of the connection methods between adjacent Mach-Zehnder interferometers in the 8×8 Mach-Zehnder interferometers of the optical switching circuit 10 are omitted. Additionally, in Figure 1 In this diagram, to prevent the illustration from becoming too complex, waveguides parallel to the row direction are depicted with waveguide lengths different from those intersecting the row direction. In this 8×8 Mach-Zehnder interferometer, the waveguides connecting two adjacent Mach-Zehnder interferometers can actually be configured to have the same waveguide length except for differences caused by manufacturing errors. Alternatively, in this 8×8 Mach-Zehnder interferometer, the waveguides connecting two adjacent Mach-Zehnder interferometers can also be configured with different waveguide lengths. Waveguides parallel to the row direction can actually be configured to have the same waveguide length except for differences in the waveguide length of those intersecting the row direction and differences caused by manufacturing errors. Alternatively, a cross-waveguide structure can be inserted into the waveguide parallel to the row direction for use when two waveguides intersecting the row direction intersect, where the waveguides parallel to the row direction and those intersecting the row direction have the same insertion loss except for differences caused by manufacturing errors. Alternatively, a cross-waveguide structure may not be inserted into the waveguide parallel to the row direction.

[0043] The first switching unit 11 switches the connection objects of each of the M Mach-Zehnder interferometers out of the 8 Mach-Zehnder interferometers included in the first column of the MZI matrix. M can be any integer, as long as it is an integer greater than or equal to N (i.e., an integer greater than or equal to 1 and less than 8 in this example). Figure 1In the example shown, M is 8. In this case, the first switching unit 11 switches the connection objects of each of the eight Mach-Zehnder interferometers with external connections. For example, the first switching unit 11 switches the connection objects based on a control signal that includes information indicating the purpose of the optical switching circuit 10. Alternatively, the first switching unit 11 may switch the connection object structure based on a control signal that includes other information, or it may switch the connection object structure by other methods.

[0044] The first switching unit 11, for example, includes one or more Mach-Zehnder interferometers that switch some or all of the connection pairs of the first ports and second ports of the aforementioned M Mach-Zehnder interferometers. These one or more Mach-Zehnder interferometers are Mach-Zehnder interferometers not included in the MZI matrix. Figure 1 In the example shown, the first switching unit 11 includes 16 Mach-Zehnder interferometers that switch all connection objects for each of the M Mach-Zehnder interferometers, including their respective first ports and second ports. For ease of explanation, these 16 Mach-Zehnder interferometers will be referred to sequentially from the first column direction towards the second column direction as First Connection Object Switching Mach-Zehnder Interferometer A1, First Connection Object Switching Mach-Zehnder Interferometer A2, ..., First Connection Object Switching Mach-Zehnder Interferometer A16. Furthermore, for ease of explanation, unless it is necessary to distinguish between each of the 16 Mach-Zehnder interferometers, they will be collectively referred to as First Connection Object Switching Mach-Zehnder Interferometer A.

[0045] Here, in Figure 1In the example shown, when i is any one of 1 to 8, the first port of the Mach-Zehnder interferometer located in row i, column 1 of the MZI matrix is ​​connected to the third port of the first connection object switching Mach-Zehnder interferometer A. Additionally, in this example, the second port of the Mach-Zehnder interferometer located in row i, column 1 of the MZI matrix is ​​connected to the third port of the first connection object switching Mach-Zehnder interferometer A. For example, the first port of Mach-Zehnder interferometer M11 is connected to the third port of the first connection object switching Mach-Zehnder interferometer A1. Furthermore, for example, the second port of Mach-Zehnder interferometer M11 is connected to the third port of the first connection object switching Mach-Zehnder interferometer A2. Additionally, for example, the first port of Mach-Zehnder interferometer M51 is connected to the third port of the first connection object switching Mach-Zehnder interferometer A9. Furthermore, for example, the second port of Mach-Zehnder interferometer M51 is connected to the third port of the first connection object switching Mach-Zehnder interferometer A10. Thus, each Mach-Zehnder interferometer included in the first column of the MZI matrix can, for example, switch between optical signal input and output with a first connection object, the Mach-Zehnder interferometer A, connected to either or both of the first and second ports.

[0046] Here, the first port of the first connection object switching Mach-Zehnder interferometer A is connected to the first connection object. Furthermore, the second port of the first connection object switching Mach-Zehnder interferometer A is connected to a second connection object, which is different from the first connection object. Therefore, the first connection object switching Mach-Zehnder interferometer A can switch the target for inputting or outputting optical signals to either the first or second connection object according to the control signal from the aforementioned control device.

[0047] Furthermore, instead of a structure that has one or more Mach-Zehnder interferometers that can switch some or all of the connection objects of each of the first ports of the M Mach-Zehnder interferometers and the second ports of the M Mach-Zehnder interferometers, the first switching unit 11 may also be another structure capable of switching the connection object.

[0048] The second switching unit 12 switches the connection objects of L of the eight Mach-Zehnder interferometers included in the Nth column of the MZI matrix with external connections. L can be any integer, as long as it is an integer greater than or equal to 1 and less than N (i.e., an integer greater than or equal to 1 and less than 8 in this example). Figure 1In the example shown, L is 8. In this case, the second switching unit 12 switches the connection objects of each of the eight Mach-Zehnder interferometers with external connections. For example, the second switching unit 12 switches the connection objects based on the control signal described above. Alternatively, the second switching unit 12 may switch the structure of the connection objects based on a control signal that includes other information, or it may switch the structure of the connection objects using other methods.

[0049] The second switching unit 12, for example, includes one or more Mach-Zehnder interferometers capable of switching some or all of the connection objects of the third ports and fourth ports of the aforementioned L Mach-Zehnder interferometers. These one or more Mach-Zehnder interferometers are Mach-Zehnder interferometers not included in the MZI matrix. Figure 1 In the example shown, the second switching unit 12 includes 16 Mach-Zehnder interferometers that switch all connection objects for the third port and the fourth port of each of the L Mach-Zehnder interferometers. For ease of explanation, these 16 Mach-Zehnder interferometers will be referred to sequentially from the first column direction toward the second column direction as Second Connection Object Switching Mach-Zehnder Interferometer B1, Second Connection Object Switching Mach-Zehnder Interferometer B2, ..., Second Connection Object Switching Mach-Zehnder Interferometer B16. Furthermore, for ease of explanation, unless it is necessary to distinguish each of the 16 Mach-Zehnder interferometers, they will be collectively referred to as Second Connection Object Switching Mach-Zehnder Interferometer B.

[0050] Here, in Figure 1In the example shown, when i is any one of 1 to 8, the third port of the Mach-Zehnder interferometer located in row i, column N of the MZI matrix is ​​connected to the first port of the second connection object switching Mach-Zehnder interferometer B. Additionally, in this example, the fourth port of the Mach-Zehnder interferometer located in row i, column N of the MZI matrix is ​​connected to the first port of the second connection object switching Mach-Zehnder interferometer B. For example, the third port of Mach-Zehnder interferometer M18 is connected to the first port of the second connection object switching Mach-Zehnder interferometer B1. Furthermore, for example, the fourth port of Mach-Zehnder interferometer M18 is connected to the first port of the second connection object switching Mach-Zehnder interferometer B2. And, for example, the third port of Mach-Zehnder interferometer M58 is connected to the first port of the second connection object switching Mach-Zehnder interferometer B9. Moreover, for example, the fourth port of Mach-Zehnder interferometer M58 is connected to the first port of the second connection object switching Mach-Zehnder interferometer B10. Thus, the Mach-Zehnder interferometers included in the Nth column of the MZI matrix can, for example, switch between optical signal input and output with a second connection object, the Mach-Zehnder interferometer B, connected to either or both of the third and fourth ports.

[0051] Here, the third port of the second connection object switching Mach-Zehnder interferometer B is connected to the third connection object. Furthermore, the fourth port of the second connection object switching Mach-Zehnder interferometer B is connected to a fourth connection object, which is different from the third connection object. Therefore, the second connection object switching Mach-Zehnder interferometer B can switch the target for inputting or outputting optical signals to either the third or fourth connection object based on the control signal from the aforementioned control device.

[0052] It should be noted that the second switching unit 12 may replace the structure of one or more Mach-Zehnder interferometers that can switch some or all of the connection objects of the third port and the fourth port of the L Mach-Zehnder interferometers, and may be other structures that can switch the connection objects.

[0053] Here, when the third and fourth connection objects are output objects of optical signals, the first and second connection objects are signal sources of optical signals. In this case, the type of optical signal input to the optical switch circuit 10 from the first connection object is different from the type of optical signal input to the optical switch circuit 10 from the second connection object. Furthermore, when the third and fourth connection objects are signal sources of optical signals, the first and second connection objects are output objects of optical signals. That is, the optical switch circuit 10 can selectively or simultaneously perform the actions of inputting an optical signal from the first row direction side and outputting an optical signal from the second row direction side, and inputting an optical signal from the second row direction side and outputting an optical signal from the first row direction side. For ease of explanation, the following will be as follows... Figure 1 As shown, the optical signals input and output between the first connection object and the third connection object and the optical switch circuit 10 will be referred to as the first optical signal. Furthermore, for ease of explanation, the following will use... Figure 1 As shown, the optical signals input and output between the second connection object and the fourth connection object and the optical switch circuit 10 are referred to as the second optical signals.

[0054] Furthermore, the optical circuit 1 includes a first switching unit 11 and a second switching unit 12, thereby enabling, for example, the switching of at least one of a plurality of optical signals input to the optical switching circuit 10 into different types of optical signals via the first switching unit 11 or the second switching unit 12. Additionally, the optical circuit 1 includes a first switching unit 11 and a second switching unit 12, thereby enabling, for example, the output of at least one of a plurality of optical signals from the optical switching circuit 10 to different output objects via the first switching unit 11 or the second switching unit 12. As a result, the optical circuit 1 can be easily used for multiple applications, simultaneously improving versatility and user convenience.

[0055] Furthermore, the first and second connection objects can be either on-chip signal sources or on-chip optical receivers, respectively. Similarly, the third and fourth connection objects can also be either on-chip signal sources or on-chip optical receivers. When the first to fourth connection objects are each on-chip, optical loop 1 can stably perform the unitary matrix operations described later. This is because, for example, when optical signals are input and output to optical loop 1 using optical fibers, the calculation errors caused by phase fluctuations during fiber propagation are known.

[0056] Alternatively, the optical loop 1 can also be a structure containing various devices (e.g., phase modulators, optical splitters, optical power monitors, etc.) positioned at desired locations within the optical loop 1 for propagating optical signals. For example, the optical loop 1 can also have phase modulators positioned at the first and second ports of the Mach-Zehnder interferometer in the first column of the optical switch loop 10. This is because, when utilizing the optical loop 1 as an optical switch or as a unitary matrix operation loop, improvements in loop controllability and reductions in loop operation errors can be expected.

[0057] As described above, the optical circuit 1 with the above structure can also switch operations depending on the application. Therefore, the various operations that the optical circuit 1 can switch operations will be explained below.

[0058] <Example 1 of optical circuit operation> Optical loop 1 can, for example, operate as a single PILOSS optical switch loop. More specifically, optical loop 1 can operate as a PILOSS optical switch loop that outputs eight first optical signals by inputting eight first optical signals. In this case, the use of optical loop 1 is, for example, the switching of optical signals required for optical communication, optical interconnection, etc.

[0059] Figure 2 This diagram illustrates an example of optical circuit 1 operating as a PILOSS optical switch circuit, where the PILOSS optical switch circuit outputs eight first optical signals by inputting eight first optical signals. Figure 2 In the example shown, the first connection object switching Mach-Zehnder interferometer A is connected to the first connection object. Furthermore, in this example, the first connection object switching Mach-Zehnder interferometer A, which inputs an optical signal to the optical switch circuit 10, is controlled by a control device to operate the first connection object switching Mach-Zehnder interferometers A1, A4, A5, A8, A9, A12, A13, and A16 respectively. Figure 2In order to clearly show the operation of the first connection object switching Mach-Zehnder interferometers A1, A4, A5, A8, A9, A12, A13, and A16, the operations of the first connection object switching Mach-Zehnder interferometers A2, A3, A6, A7, A10, A11, A14, and A15 are omitted respectively. In this case, the optical switch circuit 10 inputs four first optical signals from the first ports of each of the Mach-Zehnder interferometers M11, M31, M51, and M71, and inputs four first optical signals from the second ports of each of the Mach-Zehnder interferometers M21, M41, M61, and M81. Furthermore, in this example, under these circumstances, the optical switch circuit 10 outputs a first optical signal from the fourth port of each of the Mach-Zehnder interferometers M18, M38, M58, and M78, and outputs a first optical signal from the third port of each of the Mach-Zehnder interferometers M28, M48, M68, and M88. Therefore, in this example, as the second connection object switching Mach-Zehnder interferometer B from which the optical switch circuit 10 outputs optical signals, the control device causes the second connection object switching Mach-Zehnder interferometers B2, B3, B6, B7, B10, B11, B14, and B15 to operate respectively. Figure 2 In order to clearly show the operation of the second connection object switching Mach-Zehnder interferometers B2, B3, B6, B7, B10, B11, B14, and B15, the second connection object switching Mach-Zehnder interferometers B1, B4, B5, B8, B9, B12, B13, and B16 are omitted respectively. Furthermore, in this example, under these circumstances, the second connection object switching Mach-Zehnder interferometers B2, B3, B6, B7, B10, B11, B14, and B15 respectively output the first optical signal from the optical switch circuit 10 to the third connection object.

[0060] Here, the first switching unit 11 can switch to Figure 2 At least one of the eight first optical signals input to the optical switch circuit 10 shown is switched to a second optical signal supplied from the second connection object. This is because the first connection object switching Mach-Zehnder interferometer A of the first switching unit 11 switches the connection object from the first connection object to the second connection object according to the control signal from the control device, thereby enabling the input of the second optical signal to the optical switch circuit 10. Thus, the optical circuit 1 can easily change the combination of the eight optical signals input to the optical switch circuit 10, which operates as a PILOSS optical switch circuit, to the combination desired by the user, thereby improving both versatility and user convenience.

[0061] In addition, the second switching unit 12 can switch from Figure 2 At least one of the output targets of the eight first optical signals output from the optical switching circuit 10 shown is switched from the third connection target to the fourth connection target. This is because the second connection target switching Mach-Zehnder interferometer B of the second switching unit 12 switches the connection target from the third connection target to the fourth connection target according to the control signal from the control device, thereby enabling the first optical signal to be output from the optical switching circuit 10 to the fourth connection target. Thus, the optical circuit 1 can also easily realize optical signal exchange, wherein the optical signal is used to output to the user's desired output target, thereby improving both versatility and user convenience.

[0062] In addition, Figure 2 The input-output relationship of the optical loop 1 described herein can also be reversed. That is, the optical loop 1 can also be a structure in which the optical signal is input via the second switching unit 12 and the optical signal is output via the first switching unit 11.

[0063] Figure 3 This diagram illustrates another example of the state of optical circuit 1 operating as a PILOSS optical switch circuit, where the PILOSS optical switch circuit outputs eight first optical signals by inputting eight first optical signals. In this example, the first connection object switching Mach-Zehnder interferometer A is connected to the first connection object. Furthermore, in this example, as the first connection object switching Mach-Zehnder interferometer A that inputs optical signals to optical switch circuit 10, the first connection object switching Mach-Zehnder interferometers A1, A4, A5, A8, A9, A12, A13, and A16 are operated respectively by a control device. Figure 3In order to clearly show the operation of the first connection object switching Mach-Zehnder interferometers A1, A4, A5, A8, A9, A12, A13, and A16, the operations of the first connection object switching Mach-Zehnder interferometers A2, A3, A6, A7, A10, A11, A14, and A15 are omitted respectively. In this case, the optical switch circuit 10 inputs four first optical signals from the second ports of each of the Mach-Zehnder interferometers M11, M31, M51, and M71, and inputs four first optical signals from the first ports of each of the Mach-Zehnder interferometers M21, M41, M61, and M81. Furthermore, in this example, under these circumstances, the optical switch circuit 10 outputs a first optical signal from the third port of each of the Mach-Zehnder interferometers M18, M38, M58, and M78, and outputs a first optical signal from the fourth port of each of the Mach-Zehnder interferometers M28, M48, M68, and M88. Therefore, in this example, as the second connection object switching Mach-Zehnder interferometer B from which the optical switch circuit 10 outputs optical signals, the control device causes the second connection object switching Mach-Zehnder interferometers B2, B3, B6, B7, B10, B11, B14, and B15 to operate respectively. Figure 2 In order to clearly show the operation of the second connection object switching Mach-Zehnder interferometers B2, B3, B6, B7, B10, B11, B14, and B15, the second connection object switching Mach-Zehnder interferometers B1, B4, B5, B8, B9, B12, B13, and B16 are omitted respectively. Furthermore, in this example, under these circumstances, the second connection object switching Mach-Zehnder interferometers B2, B3, B6, B7, B10, B11, B14, and B15 respectively output the first optical signal from the optical switch circuit 10 to the third connection object.

[0064] Here, the first switching unit 11 can switch to Figure 3 At least one of the eight first optical signals input to the optical switch circuit 10 shown is switched to a second optical signal supplied from the second connection object. This is because the first connection object switching Mach-Zehnder interferometer A of the first switching unit 11 switches the connection object from the first connection object to the second connection object according to the control signal from the control device, thereby enabling the input of the second optical signal to the optical switch circuit 10. Therefore, the optical circuit 1 can easily change the combination of the eight optical signals input to the optical switch circuit 10, which operates as a PILOSS optical switch circuit, to the combination desired by the user, improving versatility and user convenience.

[0065] In addition, the first switching unit 11 can switch from Figure 3 At least one of the output targets of the eight first optical signals output from the optical switching circuit 10 shown is switched from the third connection target to the fourth connection target. This is because the second connection target switching Mach-Zehnder interferometer B of the first switching unit 11 switches the connection target from the third connection target to the fourth connection target according to the control signal from the control device, thereby enabling the output of the first optical signal from the optical switching circuit 10 to the fourth connection target. Thus, the optical circuit 1 can also easily realize optical signal exchange, wherein the optical signal is used to output to the user's desired output target, improving versatility and user convenience.

[0066] Furthermore, optical loop 1 can also be performed in parallel. Figure 2 The optical signal exchange shown Figure 3 The optical signal exchange shown. This is because, if... Figure 2 The operation of the optical switch circuit 10 shown for optical signal switching will then proceed as follows: Figure 3 The operation of the optical switch circuit 10 shown is for optical signal switching. Furthermore, this is because, if... Figure 3 The operation of the optical switch circuit 10 shown for exchanging optical signals then performs... Figure 2 The operation of the optical switch circuit 10 shown is for exchanging optical signals.

[0067] Furthermore, the switching of all the operations of the Mach-Zehnder interferometers appearing in this embodiment (e.g., the switching of the connection object by the first connection object switching Mach-Zehnder interferometer A included in the first switching unit 11) is achieved, for example, by changing the light intensity branching ratio of the Mach-Zehnder interferometer, but is not limited to this.

[0068] <Example 2 of optical circuit operation> Optical loop 1 can, for example, operate as two or more unitary matrix operation loops. More specifically, optical loop 1 can, for example, operate as two unitary matrix operation loops, which are input with seven first optical signals and output seven optical signals representing the result of performing a unitary matrix operation based on the seven input first optical signals. In this case, the purpose of optical loop 1 is, for example, unitary matrix operation.

[0069] The optical circuit 1, through the new control method described below, enables the optical switching circuit 10 to operate as two or more unitary matrix operation circuits. Furthermore, for the sake of simplicity, the following explanation will focus on the case where the optical circuit 1 enables the optical switching circuit 10 to operate as two unitary matrix operation circuits: a first unitary matrix operation circuit and a second unitary matrix operation circuit. Here, the second unitary matrix operation circuit refers to the unitary matrix operation circuit excluding the Mach-Zehnder interferometers included in the first unitary matrix operation circuit. In other words, the second unitary matrix operation circuit is a unitary matrix operation circuit different from the first unitary matrix operation circuit. For ease of explanation, the Mach-Zehnder interferometers operating as the first unitary matrix operation circuit in the 8×8 Mach-Zehnder interferometers will be referred to as first Mach-Zehnder interferometers. Similarly, for ease of explanation, the Mach-Zehnder interferometers operating as the second unitary matrix operation circuit in the 8×8 Mach-Zehnder interferometers will be referred to as second Mach-Zehnder interferometers.

[0070] For example, optical loop 1, based on control signals from the control device, causes 32 of the 8×8 Mach-Zehnder interferometers in the MZI matrix to operate as the first Mach-Zehnder interferometer, and causes the other 32 Mach-Zehnder interferometers in the 8×8 Mach-Zehnder interferometer to operate as the second Mach-Zehnder interferometer.

[0071] Figure 4 This diagram illustrates an example of 32 first Mach-Zehnder interferometers operating as first unitary matrix operation loops. Figure 4 In order to clearly show the configuration of the 32 first Mach-Zehnder interferometers, the 32 second Mach-Zehnder interferometers are omitted. Figure 4 In the example shown, the first connection object switching Mach-Zehnder interferometer A is connected to the second connection object. In this case, the second connection object is the signal source of the optical signal used for unitary matrix operations. Furthermore, in this example, the first connection object switching Mach-Zehnder interferometer A, which inputs the optical signal to the optical switch circuit 10, is operated by a control device, causing the first connection object switching Mach-Zehnder interferometers A3, A4, A7, A8, A11, A12, and A15 to operate respectively. Figure 4In order to clearly show the operation of the first connection object switching Mach-Zehnder interferometers A3, A4, A7, A8, A11, A12, and A15, the operations of the first connection object switching Mach-Zehnder interferometers A1, A2, A5, A6, A9, A10, A13, A14, and A16 are omitted respectively. In this case, the optical switch circuit 10 receives four second optical signals from the first ports of each of the Mach-Zehnder interferometers M21, M41, M61, and M81, and receives three second optical signals from the second ports of each of the Mach-Zehnder interferometers M21, M41, and M61. Furthermore, in this example, under these circumstances, the optical switch circuit 10 outputs the second optical signal after unitary matrix operation from the fourth port of each of the Mach-Zehnder interferometers M18, M38, M58, and M78, and outputs the second optical signal after unitary matrix operation from the third port of each of the Mach-Zehnder interferometers M38, M58, and M78. Therefore, in this example, as the second connection object switching Mach-Zehnder interferometer B from which the optical signal is output from the optical switch circuit 10, the control device causes the second connection object switching Mach-Zehnder interferometers B2, B5, B6, B9, B10, B13, and B14 to operate respectively. Figure 4 In this example, to clearly show the operation of the second connection object switching Mach-Zehnder interferometers B2, B5, B6, B9, B10, B13, and B14, the second connection object switching Mach-Zehnder interferometers B1, B3, B4, B7, B8, B11, B12, B15, and B16 are omitted respectively. Furthermore, in this example, under these circumstances, the second connection object switching Mach-Zehnder interferometers B2, B5, B6, B9, B10, B13, and B14 output the second optical signal after unitary matrix operation from the optical switch circuit 10 to the fourth connection object. In this case, the fourth connection object is a circuit that processes the second optical signal after unitary matrix operation from the optical switch circuit 10 (e.g., a circuit performing further optical operations, an optical switch circuit, a circuit that converts the optical signal into an electrical signal and performs information processing, other information processing devices, etc.), but is not limited to this.

[0072] In addition, Figure 4 In the example shown, the first and second Mach-Zehnder interferometers included in the MZI matrix are alternately located along the row and column directions of the MZI matrix, respectively. More specifically, in Figure 4In the example shown, the first Mach-Zehnder interferometer and the second Mach-Zehnder interferometer are alternately configured throughout all rows 1 through 8. Additionally, in this example, the first Mach-Zehnder interferometer and the second Mach-Zehnder interferometer are alternately configured throughout all columns 1 through 8. Thus, when the first Mach-Zehnder interferometer operates as the first unitary matrix operation loop, as... Figure 4 As shown, the first unitary matrix operation loop operates as a unitary matrix operation loop that performs unitary matrix operations with 7 optical signals as inputs and 7 optical signals as outputs. However, in Figure 4 In the example shown, Figure 4 The Mach-Zehnder interferometers M12, M14, M16, M18, M38, M58, M78, M81, M83, M85, and M87, which are shaded in the image, are the first Mach-Zehnder interferometers operating as phase modulators. Here, operating as a phase modulator means the Mach-Zehnder interferometer is in a Bar (direct-through) state. The optical signal input to the first port is phase-modulated and output from the third port. The optical signal input to the second port is phase-modulated and output from the fourth port. That is, Figure 4 In the mid-shaded Mach-Zehnder interferometers M12, M14, M16, M18, M38, M58, M78, M81, M83, M85, and M87, the intensity branching ratio in Bar:Cross is 100:0. On the other hand, in Figure 4 The intensity branching ratios of the unshadowed Mach-Zehnder interferometers M21, M23, M25, M27, M32, M34, M36, M41, M43, M45, M47, M52, M54, M56, M61, M63, M65, M67, M72, M74, and M76 are calculated according to the desired unitary matrix to obtain the desired ratio. Furthermore, in... Figure 4 In the shaded Mach-Zehnder interferometer, Mach-Zehnder interferometers M18, M38, M58, and M78 can be in a cross-connected state. The optical signal input to the first port is phase-modulated and output from the fourth port. The optical signal input to the second port is phase-modulated and output from the third port. That is, in this case, the intensity branching ratio of each of the Mach-Zehnder interferometers M18, M38, M58, and M78 is 0:100 in Bar:Cross. Therefore, Figure 4 The configuration of the first Mach-Zehnder interferometer shown is the same as that of the Bell-type optical loop topology. That is, Figure 4 The 32 first Mach-Zehnder interferometers shown operate as the first unitary matrix operation loop.

[0073] Here, the first unitary matrix operation loop can also replace the unitary matrix operation loop that performs unitary matrix operations with 7 optical signals as input and 7 optical signals as output, and instead operate as a unitary matrix operation loop that takes 6 or fewer optical signals as input and takes those 6 or fewer optical signals as output. In this case, in an 8×8 Mach-Zehnder interferometer, the configuration of the Mach-Zehnder interferometer used as the first Mach-Zehnder interferometer in the MZI matrix and Figure 4 The configurations shown are different. For example, the configuration of the first Mach-Zehnder interferometer within the MZI matrix can be determined to be the same as the topology of the Bell-type optical loop. This also applies to the configuration of the second Mach-Zehnder interferometer. That is, by determining the configurations of both the first and second Mach-Zehnder interferometers to be the same as the topology of the Bell-type optical loop, optical loop 10 can operate as two unitary matrix operation loops. Furthermore, by finding that optical loop 1 within the MZI matrix has the same topology as the Bell-type optical loop, optical loop 10 can also operate as three or more unitary matrix operation loops. Moreover, the configuration of the first Mach-Zehnder interferometer within the MZI matrix can also be determined by other methods.

[0074] In addition, the first switching unit 11 can switch to Figure 4 At least one of the seven second optical signals input to the optical switch circuit 10 shown is switched to a first optical signal supplied from the first connection object. This is because the first connection object switching Mach-Zehnder interferometer A of the first switching unit 11 switches the connection object from the second connection object to the first connection object according to the control signal from the control device, thereby enabling the input of the first optical signal to the optical switch circuit 10. As a result, the optical circuit 1 can easily change the combination of the seven optical signals input to the optical switch circuit 10, which operates as a first unitary matrix operation circuit, to the combination desired by the user, thereby improving both versatility and user convenience.

[0075] In addition, the second switching unit 12 can switch from Figure 4 At least one of the seven optical signals output from the optical switching circuit 10 shown is switched from the fourth connection object to the third connection object. This is because the second connection object switching Mach-Zehnder interferometer B of the second switching unit 12 switches the connection object from the fourth connection object to the third connection object according to the control signal from the control device, thereby enabling the output of the second optical signal from the optical switching circuit 10 to the third connection object. Therefore, the optical circuit 1 can easily output each optical signal after the first unitary matrix operation to the desired output object, thus improving both versatility and user convenience.

[0076] In addition, Figure 4The input-output relationship of the optical loop 1 described herein can also be reversed. That is, the optical loop 1 can also be a structure in which the optical signal is input via the second switching unit 12 and the optical signal after unitary matrix operation is output via the first switching unit 11.

[0077] on the one hand, Figure 5 This diagram illustrates an example of 32 second Mach-Zehnder interferometers operating as second unitary matrix operation loops. Figure 5 In order to clearly show the configuration of the 32 second Mach-Zehnder interferometers, the 32 first Mach-Zehnder interferometers are omitted. Figure 5 In the example shown, the first connection object switching Mach-Zehnder interferometer A is connected to the second connection object. In this case, the second connection object is the signal source of the optical signal used for unitary matrix operations. Furthermore, in this example, the first connection object switching Mach-Zehnder interferometer A, which inputs the optical signal to the optical switch circuit 10, is operated by a control device, causing the first connection object switching Mach-Zehnder interferometers A2, A5, A6, A9, A10, A13, and A14 to operate respectively. Figure 5 In order to clearly show the operation of the first connection object switching Mach-Zehnder interferometers A2, A5, A6, A9, A10, A13, and A14, the operations of the first connection object switching Mach-Zehnder interferometers A1, A3, A4, A7, A8, A11, A12, A15, and A16 are omitted respectively. In this case, the optical switch circuit 10 receives four second optical signals from the second ports of each of the Mach-Zehnder interferometers M11, M31, M51, and M71, and receives three second optical signals from the first ports of each of the Mach-Zehnder interferometers M31, M51, and M71. Furthermore, in this example, under these circumstances, the optical switch circuit 10 outputs the second optical signal after unitary matrix operation from the third port of each of the Mach-Zehnder interferometers M28, M48, M68, and M88, and outputs the second optical signal after unitary matrix operation from the fourth port of each of the Mach-Zehnder interferometers M28, M48, and M68. Therefore, in this example, as the second connection object switching Mach-Zehnder interferometer B from which the optical signal is output from the optical switch circuit 10, the control device causes the second connection object switching Mach-Zehnder interferometers B3, B4, B7, B8, B11, B12, and B15 to operate respectively. Figure 5In this example, to clearly show the operation of the second connection object switching Mach-Zehnder interferometers B2, B5, B6, B9, B10, B13, and B14, the second connection object switching Mach-Zehnder interferometers B1, B3, B4, B7, B8, B11, B12, B15, and B16 are omitted respectively. Furthermore, in this example, under these circumstances, the second connection object switching Mach-Zehnder interferometers B2, B5, B6, B9, B10, B13, and B14 output the second optical signal after unitary matrix operation from the optical switch circuit 10 to the fourth connection object. In this case, the fourth connection object is a circuit that processes the second optical signal after unitary matrix operation from the optical switch circuit 10 (e.g., a circuit performing further optical operations, an optical switch circuit, a circuit that converts the optical signal into an electrical signal and performs information processing, other information processing devices, etc.), but is not limited to this.

[0078] In addition, Figure 5 In the example shown, the first and second Mach-Zehnder interferometers included in the MZI matrix are also alternately located in the row and column directions of the MZI matrix, respectively. More specifically, in Figure 5 In the example shown, the first Mach-Zehnder interferometer and the second Mach-Zehnder interferometer are alternately configured throughout all rows 1 through 8. Additionally, in this example, the first Mach-Zehnder interferometer and the second Mach-Zehnder interferometer are alternately configured throughout all columns 1 through 8. Thus, when the second Mach-Zehnder interferometer operates as a second unitary matrix operation loop, as... Figure 5 As shown, the second unitary matrix operation loop operates as a unitary matrix operation loop that performs unitary matrix operations with 7 optical signals as inputs and 7 optical signals as outputs. Furthermore, if... Figure 5 The configuration of the second Mach-Zehnder interferometer shown is similar to Figure 4 The overlapping configurations of the first Mach-Zehnder interferometer shown constitute the configuration of the MZI matrix. That is, Figure 4 and Figure 5 The configuration of the first and second Mach-Zehnder interferometers shown is an example of a configuration in which the 8×8 Mach-Zehnder interferometers included in the optical switch circuit 10 are divided into two, operating as the first and second unitary matrix operation circuits, respectively. However, in Figure 5 In the example shown, Figure 5 The shaded Mach-Zehnder interferometers M11, M13, M15, M17, M28, M48, M68, M82, M84, M86, and M88 are the second Mach-Zehnder interferometers that operate as phase modulators (Bar states). That is, Figure 5In the mid-shaded Mach-Zehnder interferometers M12, M14, M16, M18, M38, M58, M78, M81, M83, M85, and M87, the intensity branching ratio in Bar:Cross is 100:0. On the other hand, in Figure 5 The intensity branching ratios of the unshadowed Mach-Zehnder interferometers M21, M23, M25, M27, M32, M34, M36, M41, M43, M45, M47, M52, M54, M56, M61, M63, M65, M67, M72, M74, and M76 are calculated according to the desired unitary matrix to obtain the desired ratio. Furthermore, in... Figure 5 In the shaded Mach-Zehnder interferometer, Mach-Zehnder interferometers M18, M38, M58, and M78 can be in a cross-connected state. The optical signal input to the first port is phase-modulated and output from the fourth port. The optical signal input to the second port is phase-modulated and output from the third port. That is, in this case, the intensity branching ratio of each of the Mach-Zehnder interferometers M18, M38, M58, and M78 is 0:100 in Bar:Cross. Therefore, Figure 5 The configuration of the second Mach-Zehnder interferometer shown is the same as that of the Bell-type optical loop topology. That is, Figure 5 The 32 second Mach-Zehnder interferometers shown operate as second unitary matrix operation loops.

[0079] Here, the first switching unit 11 can switch to Figure 5 At least one of the seven second optical signals input to the optical switch circuit 10 shown is switched to a first optical signal supplied from the first connection object. This is because the first connection object switching Mach-Zehnder interferometer A of the first switching unit 11 switches the connection object from the second connection object to the first connection object according to the control signal from the control device, thereby enabling the input of the first optical signal to the optical switch circuit 10. As a result, the optical circuit 1 can easily change the combination of the seven optical signals input to the optical switch circuit 10, which operates as a second unitary matrix operation circuit, to the combination desired by the user, thereby improving both versatility and user convenience.

[0080] In addition, the second switching unit 12 can switch from Figure 5At least one of the seven optical signals output from the optical switching circuit 10 shown is switched from the fourth connection object to the third connection object. This is because the second connection object switching Mach-Zehnder interferometer B of the second switching unit 12 switches the connection object from the fourth connection object to the third connection object according to the control signal from the control device, thereby enabling the output of the second optical signal from the optical switching circuit 10 to the third connection object. Therefore, the optical circuit 1 can easily output each optical signal after the second unitary matrix operation to the desired output object, thus improving both versatility and user convenience.

[0081] In addition, Figure 5 The input-output relationship of the optical loop 1 described herein can also be reversed. That is, the optical loop 1 can also be a structure in which the optical signal is input via the second switching unit 12 and the optical signal after unitary matrix operation is output via the first switching unit 11.

[0082] <Examples of how to use Action Example 1 and Action Example 2> Here, examples of how to use each of the above-described action examples 1 and 2 will be explained.

[0083] For example, optical loop 1 can input an optical signal from the port of the signal source for the optical signal used for optical switching and output the input optical signal to the port of the optical receiver for the optical signal used for optical switching. In this case, depending on the application, the optical switching loop 10 of optical loop 1 can operate as a PILOSS optical switching loop or as a unitary matrix operation loop. For example, in this case, when the optical switching loop 10 operates as a PILOSS optical switching loop, optical loop 1 functions as a loop for optical signal switching.

[0084] Alternatively, for example, optical loop 1 can input an optical signal from the port of the signal source for the optical signal used for optical switching, and output the input optical signal to the port of the optical receiver for inputting the optical signal used for unitary matrix operation. In this case, depending on the application, the optical switching loop 10 of optical loop 1 can operate as a PILOSS optical switching loop or as a unitary matrix operation loop. For example, in this case, when the optical switching loop 10 operates as a PILOSS optical switching loop, optical loop 1 is used as a receiver for receiving information.

[0085] Alternatively, for example, optical loop 1 can input an optical signal from the port of the signal source for unitary matrix operations and output the input optical signal to the port of the optical receiver for input optical switching. In this case, depending on the application, the optical switching loop 10 of optical loop 1 can operate as a PILOSS optical switching loop or as a unitary matrix operation loop. For example, in this case, when the optical switching loop 10 operates as a PILOSS optical switching loop, optical loop 1 functions as a transmitter for transmitting information.

[0086] Additionally, for example, optical loop 1 can input an optical signal from the port of the signal source for the unitary matrix operation and output the input optical signal to the port of the optical receiver for the unitary matrix operation. In this case, depending on the application, the optical switch loop 10 of optical loop 1 can operate as a PILOSS optical switch loop or as a unitary matrix operation loop. For example, in this case, when the optical switch loop 10 operates as a unitary matrix operation loop, optical loop 1 functions as a loop performing unitary matrix operations. For example, in this case, when the optical switch loop 10 operates as a PILOSS optical switch loop, optical loop 1 functions as a loop for performing loop correction to optimize the operation of the PILOSS optical switch loop.

[0087] Furthermore, for example, optical loop 1 can monitor the operation of optical switch loop 10 as a PILOSS optical switch loop by utilizing the second switching unit 12. Specifically, in this case, the light intensity branch ratio of the second connection object switching Mach-Zehnder interferometer B included in the second switching unit 12 in optical loop 1 is set to 99:1 in Bar:Cross. Therefore, the second connection object switching Mach-Zehnder interferometer B can output 99% of the optical signal output from optical switch loop 10 from the third port and 1% of the optical signal from the fourth port. As a result, the information processing device monitoring the operation of optical loop 1 can monitor whether the operation of optical loop 1 is normal based on the 1% component. In this case, the optical signal input to optical switch loop 10 can be an optical signal for optical switching or an optical signal for unitary matrix operations. Furthermore, the light intensity branch ratio can be replaced by other light intensity branch ratios instead of 99:1.

[0088] Additionally, for example, in optical loop 1, such as Figure 6 As shown, it can also be a structure in which the third and fourth ports of the Mach-Zehnder interferometers included in the MZI matrix described above are connected to the cross waveguides CS. Figure 6 This is a diagram illustrating an example of an MZI matrix with cross-waveguides (CS) connected to the third and fourth ports of each Mach-Zehnder interferometer. However, in Figure 6In order to prevent the diagram from becoming complicated, only the cross waveguides connected to the third and fourth ports of each Mach-Zehnder interferometer included in the first row of the MZI matrix are shown by the symbol CS.

[0089] exist Figure 6 In this context, the cross waveguide CS connected to the third and fourth ports of a Mach-Zehnder interferometer is a waveguide in which the output objects of the third port and the fourth port are interchanged. The configuration of the cross waveguide CS can be a known configuration or a configuration to be developed.

[0090] In the MZI matrix Figure 6 In the structure shown, the optical switch circuit 10 is known to have a wider operating band as a PILOSS optical switch. That is, the optical circuit 1 can thus improve its versatility as a PILOSS optical switch.

[0091] As described above, the optical circuit 1 of the embodiment includes: an optical switching circuit 10, which includes 8×8 Mach-Zehnder interferometers arranged in an 8x8 matrix; a first switching unit 11, which switches the connection objects of M Mach-Zehnder interferometers among the 8 Mach-Zehnder interferometers included in the first column of the MZI matrix with external connections; and a second switching unit 12, which switches the connection objects of L Mach-Zehnder interferometers included in the 8th column of the MZI matrix with external connections. Thus, the optical circuit 1 can simultaneously improve versatility and user convenience.

[0092] <Example 1 of a variation of the optical circuit structure> The following describes a modified example 1 of the structure of optical circuit 1. Figure 7 This is a diagram showing another example of the structure of optical loop 1.

[0093] exist Figure 7In the example shown, the first switching unit 11 does not have the first connection object switching Mach-Zehnder interferometer A1 and the first connection object switching Mach-Zehnder interferometer A16, but has 15 first connection object switching Mach-Zehnder interferometers A2 to A15. Similarly, in this example, the second switching unit 12 does not have the second connection object switching Mach-Zehnder interferometer B1 and the second connection object switching Mach-Zehnder interferometer B16, but has 15 second connection object switching Mach-Zehnder interferometers B2 to B15. Alternatively, the first switching unit 11 may also have the first connection object switching Mach-Zehnder interferometer A1 and the first connection object switching Mach-Zehnder interferometer A16. Furthermore, the second switching unit 12 may include a second connection object switching Mach-Zehnder interferometer B1 and a second connection object switching Mach-Zehnder interferometer B16.

[0094] In addition, Figure 7 In the second switching unit 12 shown, when i is any one of 2, 4, 6, 8, 10, 12, or 14, the fourth port of the second connection object switching Mach-Zehnder interferometer Bi is connected to the third port of the second connection object switching Mach-Zehnder interferometer Bi+1 via the amplitude modulator AS. In other words, in Figure 7 In the example shown, when i is any one of 1 to 7, the fourth port of the second connection object switching Mach-Zehnder interferometer B2i, which is connected to the fourth port of the Mach-Zehnder interferometer located in row i, column 8 of the MZI matrix, is connected via an amplitude modulator AS to the third port of the second connection object switching Mach-Zehnder interferometer B2i+1, which is connected to the third port of the Mach-Zehnder interferometer located in row i+1, column 8 of the MZI matrix. For example, the fourth port of the second connection object switching Mach-Zehnder interferometer B2 is connected via an amplitude modulator AS to the third port of the second connection object switching Mach-Zehnder interferometer B3. In this case, the optical signal output from the fourth port is amplitude modulated by the amplitude modulator AS and then input to the third port. That is, Figure 7 The illustrated optical loop 1 also includes multiple amplitude modulators AS, which modulate the amplitude of the optical signal output from a portion of the 14 second-connected Mach-Zehnder interferometers B, and input the modulated optical signal to another portion of the 14 Mach-Zehnder interferometers. Furthermore, the amplitude modulators AS can also be structures that modulate the phase of the optical signal. In this case, the amplitude modulators AS modulate both the amplitude and phase of the optical signal.

[0095] Figure 7 The optical circuit 1 of the structure shown outputs optical signals from the third port of the second connection object switching Mach-Zehnder interferometer B2i and the fourth port of the second connection object switching Mach-Zehnder interferometer B2i+1 when i is any one of 1 to 7, thereby enabling it to operate as a PILOSS optical switch circuit.

[0096] on the one hand, Figure 7 The optical loop 1 shown can function as a matrix operation loop that performs three operations sequentially on the optical signal: the first unitary matrix operation, the diagonal matrix operation, and the second unitary matrix operation.

[0097] here, Figure 8 It is shown Figure 7 The diagram shown illustrates an example of optical loop 1 operating as a unitary matrix operation loop performing the first unitary matrix operation. Additionally, Figure 8 The operation of the optical switch circuit 10 as a unitary matrix operation circuit shown is related to... Figure 4 The actions described in the previous section are the same, so the description is omitted.

[0098] exist Figure 8 In the example shown, the seven Mach-Zehnder interferometers A3, A4, A7, A8, A11, A12, and A15 (first connection object switching Mach-Zehnder interferometers A) are connected to the second connection object. In this example, the second connection object is the signal source of the optical signal used for matrix operations. Optical loop 1 performs the first unitary matrix operation in optical switching loop 10 on the seven optical signals input from this signal source. Afterward, the optical signals after the first unitary matrix operation are output to the second connection object switching Mach-Zehnder interferometers B2, B5, B6, B9, B10, B13, and B14, respectively. Thus, the optical signals output by the second connection object switching Mach-Zehnder interferometers B2, B5, B6, B9, B10, B13, and B14 are amplitude modulated by the amplitude modulator AS. This amplitude modulation is equivalent to the aforementioned diagonal matrix operation. After being amplitude modulated, as... Figure 9 As shown, the optical signal is input to the optical switch circuit 10 again via the second connection object switching Mach-Zehnder interferometers B3, B4, B7, B8, B11, B12, and B15. Figure 9 It is shown Figure 7 The diagram shows an example of optical loop 1 operating as a unitary matrix operation loop for the second unitary matrix operation. Furthermore, in Figure 9In this circuit, the Mach-Zehnder interferometers operating as phase modulators are Mach-Zehnder interferometers M11, M13, M15, M17, M31, M51, M71, M82, M84, M86, and M88. Optical loop 1 performs a second unitary matrix operation in optical switching loop 10 on the input optical signal. Afterwards, Mach-Zehnder interferometers A2, A5, A6, A9, A10, A13, and A14, switched from the first connection point, output the optical signal after the second unitary matrix operation. As described above, optical loop 1 can operate as a matrix operation loop that sequentially performs the first unitary matrix operation, diagonal matrix operation, and second unitary matrix operation on the optical signal. Therefore, optical loop 1 is not limited to unitary matrix operations and can perform arbitrary matrix operations using the optical signal. Furthermore, regarding... Figure 9 The operation of the optical switch circuit 10 as a unitary matrix operation circuit, except for the signal flow from the second row direction to the first row direction and the position of phase modulation, is related to... Figure 5 The actions described herein are the same, therefore the description is omitted. Furthermore, in [the context of...], [the description is missing here]. Figure 8 , Figure 9 In the operation loop of the unitary matrix shown, the functions of the first column and the eighth column can also be interchanged. For example, in Figure 8 In the example shown, M21, M41, and M61 can also be used as phase modulators instead of Mach-Zehnder interferometers M38, M58, and M78. For example, in Figure 9 In the example shown, M28, M48, and M68 can also be used as phase modulators instead of Mach-Zehnder interferometers M31, M51, and M71. Additionally, when used as... Figure 8 , Figure 9 In the operation of the unitary matrix operation loop shown, it is also possible to avoid using part or all of the Mach-Zehnder interferometers in the first and eighth columns as phase modulators. For example, in Figure 8 In the example shown, the intensity branch ratios of the Mach-Zehnder interferometers M21, M41, M61, M38, M58, and M78 are obtained by performing a desired unitary matrix operation. For example, in Figure 9 In the example shown, the intensity branching ratios of the Mach-Zehnder interferometers M31, M51, M71, M28, M48, and M68 are obtained according to the desired unitary matrix operation. At this time, the order of the Mach-Zehnder interferometers performing the unitary matrix operation loop increases from 7 to 8. Thus, by increasing the order of the Mach-Zehnder interferometers performing the unitary matrix operation, optical loop 1 can improve the controllability of the unitary matrix operation loop, thereby reducing the calculation error of the unitary matrix operation.

[0099] <Example 2 of the modified structure of the optical circuit> The following is for reference Figure 10 Example 2, a variation of the structure of optical circuit 1, will be described in detail. Figure 10 This is another example of the structure of optical loop 1.

[0100] exist Figure 10 In the example shown, the first switching unit 11 has the same as Figure 1 The second switching unit 12 has the same structure as the first switching unit 11 shown. Additionally, in this example, the second switching unit 12 has a structure that... Figure 1 The structure of the second switching unit 12 shown is similar to Figure 7 The structure is formed by combining the structures of the second switching unit 12 shown. Therefore, in Figure 10 In the second switching unit 12 shown, when i is any one of 2, 4, 6, 8, 10, 12, or 14, the fourth port of the second connection target switching Mach-Zehnder interferometer Bi is connected to the third port of the second connection target switching Mach-Zehnder interferometer Bi+1 via the amplitude modulator AS. Furthermore, Figure 10 The second switching unit 12 shown includes a second connection object switching Mach-Zehnder interferometer B1 and a second connection object switching Mach-Zehnder interferometer B16.

[0101] In addition, Figure 10 In the example shown, the optical loop 1 further includes: a first connection object addition unit 13, which adds types of connection objects that can be switched by the first switching unit 11; and a second connection object addition unit 14, which adds types of connection objects that can be switched by the second switching unit 12. Therefore, for example, the optical loop 1 can realize all combinations of the operation and usage methods of the optical loop 1 described above based on control signals from the control device. As a result, the optical loop 1 can simultaneously improve versatility and user convenience.

[0102] The first connection object addition unit 13 includes Mach-Zehnder interferometers that are respectively connected to some or all of M Mach-Zehnder interferometers, and the M Mach-Zehnder interferometers are connected to the first switching unit 11. Figure 10 In the example shown, the first connection object addition unit 13 includes seven Mach-Zehnder interferometers, namely Mach-Zehnder interferometers C1 to C7.

[0103] For example, the third port of the Mach-Zehnder interferometer C1 is connected to the second port of the first connection object switching Mach-Zehnder interferometer A2. Therefore, by providing the first connection object addition unit 13, the optical loop 1 can switch the connection object of the second port of the Mach-Zehnder interferometer M11 to any one of three connection objects: a connection object connected to the first port of the first connection object switching Mach-Zehnder interferometer A2, or a connection object connected to both the first and second ports of the Mach-Zehnder interferometer C1. This is equivalent to increasing the number of connection objects of the second port of the Mach-Zehnder interferometer M11 from two to three. That is, the first connection object addition unit 13 for the Mach-Zehnder interferometer C1 can add more types of connection objects to the Mach-Zehnder interferometer M11. Alternatively, instead of connecting the Mach-Zehnder interferometer C1 to the second port of the first connection object switching Mach-Zehnder interferometer A2 via the third port, the Mach-Zehnder interferometer C1 can also be connected to the second port of the first connection object switching Mach-Zehnder interferometer A2 via the fourth port. Furthermore, the third port of the Mach-Zehnder interferometer C1 can also be a structure that connects to the first port of the Mach-Zehnder interferometer A2, which is the first connection object.

[0104] Similarly, the third port of Mach-Zehnder interferometer C2 is connected to the second port of first connection object switching Mach-Zehnder interferometer A5. Therefore, the first connection object addition unit 13, equipped with Mach-Zehnder interferometer C2, can add connection object types to Mach-Zehnder interferometer M31. Furthermore, the third port of Mach-Zehnder interferometer C3 is connected to the second port of first connection object switching Mach-Zehnder interferometer A6. Therefore, the first connection object addition unit 13, equipped with Mach-Zehnder interferometer C3, can add connection object types to Mach-Zehnder interferometer M31. Furthermore, the third port of Mach-Zehnder interferometer C4 is connected to the second port of first connection object switching Mach-Zehnder interferometer A9. Therefore, the first connection object addition unit 13, equipped with Mach-Zehnder interferometer C4, can add connection object types to Mach-Zehnder interferometer M51. Furthermore, the third port of Mach-Zehnder interferometer C5 is connected to the second port of first connection object switching Mach-Zehnder interferometer A10. Therefore, the first connection object addition unit 13 equipped with the Mach-Zehnder interferometer C5 can add connection object types to the Mach-Zehnder interferometer M51. Furthermore, the third port of the Mach-Zehnder interferometer C6 is connected to the second port of the first connection object switching Mach-Zehnder interferometer A13. Therefore, the first connection object addition unit 13 equipped with the Mach-Zehnder interferometer C6 can add connection object types to the Mach-Zehnder interferometer M71. Furthermore, the third port of the Mach-Zehnder interferometer C7 is connected to the second port of the first connection object switching Mach-Zehnder interferometer A14. Therefore, the first connection object addition unit 13 equipped with the Mach-Zehnder interferometer C7 can add connection object types to the Mach-Zehnder interferometer M71.

[0105] The second connection object addition unit 14 includes Mach-Zehnder interferometers that are connected to some or all of L Mach-Zehnder interferometers, which are connected to the second switching unit 12. Figure 10 In the example shown, the second connection object addition unit 14 has 14 Mach-Zehnder interferometers, from Mach-Zehnder interferometer D1 to Mach-Zehnder interferometer D14.

[0106] The first port of the Mach-Zehnder interferometer D1 is connected to the third port of the Mach-Zehnder interferometer B2 via a second connection object switching mechanism. Therefore, by providing the second connection object addition unit 14, optical loop 1 can switch the connection object of the fourth port of the Mach-Zehnder interferometer M18 to any one of three connection objects: a connection object connected to the fourth port of the Mach-Zehnder interferometer B2 via a second connection object switching mechanism, or a connection object connected to both the first and second ports of the Mach-Zehnder interferometer D1. This is equivalent to increasing the number of connection objects at the fourth port of the Mach-Zehnder interferometer M18 from two to three. That is, the second connection object addition unit 14 for the Mach-Zehnder interferometer D1 can add more types of connection objects to the Mach-Zehnder interferometer M18. Furthermore, instead of the structure where the third port of the Mach-Zehnder interferometer B2 is connected via the first port to the second connection object switching mechanism, the Mach-Zehnder interferometer D1 can also be connected via the third port of the Mach-Zehnder interferometer B2 via the second port to the second connection object switching mechanism.

[0107] Similarly, the first port of Mach-Zehnder interferometer D2 is connected to the fourth port of second connection object switching Mach-Zehnder interferometer B3. Therefore, the second connection object addition unit 14, equipped with Mach-Zehnder interferometer D2, can add connection object types to Mach-Zehnder interferometer M28. Furthermore, the first port of Mach-Zehnder interferometer D3 is connected to the third port of second connection object switching Mach-Zehnder interferometer B4. Therefore, the second connection object addition unit 14, equipped with Mach-Zehnder interferometer D3, can add connection object types to Mach-Zehnder interferometer M28. Moreover, the first port of Mach-Zehnder interferometer D4 is connected to the fourth port of second connection object switching Mach-Zehnder interferometer B5. Therefore, the second connection object addition unit 14, equipped with Mach-Zehnder interferometer D4, can add connection object types to Mach-Zehnder interferometer M38. Furthermore, the first port of Mach-Zehnder interferometer D5 is connected to the third port of second connection object switching Mach-Zehnder interferometer B6. Therefore, the second connection object addition unit 14, equipped with the Mach-Zehnder interferometer D5, can add connection object types to the Mach-Zehnder interferometer M38. Furthermore, the first port of the Mach-Zehnder interferometer D6 is connected to the fourth port of the second connection object switching Mach-Zehnder interferometer B7. Therefore, the second connection object addition unit 14, equipped with the Mach-Zehnder interferometer D6, can add connection object types to the Mach-Zehnder interferometer M48. Furthermore, the first port of the Mach-Zehnder interferometer D7 is connected to the third port of the second connection object switching Mach-Zehnder interferometer B8. Therefore, the second connection object addition unit 14, equipped with the Mach-Zehnder interferometer D7, can add connection object types to the Mach-Zehnder interferometer M48. Furthermore, the first port of the Mach-Zehnder interferometer D8 is connected to the fourth port of the second connection object switching Mach-Zehnder interferometer B9. Therefore, the second connection object addition unit 14, equipped with the Mach-Zehnder interferometer D8, can add connection object types to the Mach-Zehnder interferometer M58. Furthermore, the first port of the Mach-Zehnder interferometer D9 is connected to the third port of the second connection object switching Mach-Zehnder interferometer B10. Therefore, the second connection object addition unit 14, equipped with the Mach-Zehnder interferometer D9, can add connection object types to the Mach-Zehnder interferometer M58. Moreover, the first port of the Mach-Zehnder interferometer D10 is connected to the fourth port of the second connection object switching Mach-Zehnder interferometer B11. Therefore, the second connection object addition unit 14, equipped with the Mach-Zehnder interferometer D10, can add connection object types to the Mach-Zehnder interferometer M68. Additionally, the first port of the Mach-Zehnder interferometer D11 is connected to the third port of the second connection object switching Mach-Zehnder interferometer B12.Therefore, the second connection object addition unit 14, equipped with the Mach-Zehnder interferometer D11, can add connection object types for the Mach-Zehnder interferometer M68. Furthermore, the first port of the Mach-Zehnder interferometer D12 is connected to the fourth port of the second connection object switching Mach-Zehnder interferometer B13. Therefore, the second connection object addition unit 14, equipped with the Mach-Zehnder interferometer D12, can add connection object types for the Mach-Zehnder interferometer M78. Additionally, the first port of the Mach-Zehnder interferometer D13 is connected to the third port of the second connection object switching Mach-Zehnder interferometer B14. Therefore, the second connection object addition unit 14, equipped with the Mach-Zehnder interferometer D13, can add connection object types for the Mach-Zehnder interferometer M78. Furthermore, the first port of the Mach-Zehnder interferometer D14 is connected to the fourth port of the second connection object switching Mach-Zehnder interferometer B15. Therefore, the second connection object addition unit 14 equipped with the Mach-Zehnder interferometer D14 can add the types of connection objects of the Mach-Zehnder interferometer M88.

[0108] As described above, the optical loop 1 can also be configured to further include: a first connection object addition unit 13, which adds types of connection objects that can be switched by the first switching unit 11; and a second connection object addition unit 14, which adds types of connection objects that can be switched by the second switching unit 12. In this case, for example, the optical loop 1 can realize all combinations of the operation and usage methods of the optical loop 1 described above based on control signals from the control device. As a result, the optical loop 1 can improve both versatility and user convenience.

[0109] Furthermore, the above descriptions can be combined in any way.

[0110] As described above, the optical circuit 1 of the embodiment includes: an optical switching circuit 10, which includes 8×8 Mach-Zehnder interferometers arranged in an 8x8 matrix; a first switching unit 11, which switches the connection objects of M Mach-Zehnder interferometers among the 8 Mach-Zehnder interferometers included in the first column of the MZI matrix with external connections; and a second switching unit 12, which switches the connection objects of L Mach-Zehnder interferometers included in the 8th column of the MZI matrix with external connections. Thus, the optical circuit 1 can simultaneously improve versatility and user convenience.

[0111] In addition, the input light used for the optical signal described above can be laser light, quantum light, or other types of light.

[0112] <Postscript> [1] An optical circuit includes: an optical switching circuit comprising N×N Mach-Zehnder interferometers arranged in an N-row N-column matrix, where N is an integer greater than or equal to 8; a first switching unit that switches the connection of each of M Mach-Zehnder interferometers from the N Mach-Zehnder interferometers in the first column of the matrix to an external connection object, where M is any integer greater than or equal to 1 and less than N; and a second switching unit that switches the connection of each of L Mach-Zehnder interferometers from the N Mach-Zehnder interferometers in the Nth column of the matrix to an external connection object, where L is any integer greater than or equal to 1 and less than N. [2] According to the optical circuit described in [1], the N×N Mach-Zehnder interferometers each have: a first port and a second port, the first port and the second port being disposed on the side of the first row direction from the Nth column of the matrix toward the first column of the matrix, and capable of inputting and outputting optical signals; and a third port and a fourth port, the third port and the fourth port being disposed on the side of the second row direction from the first column of the matrix toward the Nth column of the matrix, and capable of inputting and outputting optical signals. The first switching unit switches a portion or all of the connection objects of the first port of each of the M Mach-Zehnder interferometers and the second port of each of the M Mach-Zehnder interferometers. The second switching unit switches a portion or all of the connection objects of the third port of each of the L Mach-Zehnder interferometers and the fourth port of each of the M Mach-Zehnder interferometers. [3] According to the optical circuit described in [2], the first switching unit includes one or more Mach-Zehnder interferometers that can switch some or all of the connection objects of the first port of each of the M Mach-Zehnder interferometers and the second port of each of the M Mach-Zehnder interferometers, and the second switching unit includes one or more Mach-Zehnder interferometers that can switch some or all of the connection objects of the third port of each of the L Mach-Zehnder interferometers and the fourth port of each of the L Mach-Zehnder interferometers. [4] According to the optical circuit described in [3], the second switching unit includes multiple Mach-Zehnder interferometers that switch between a portion or all of the connection objects of the third port and the fourth port of each of the L Mach-Zehnder interferometers. The optical circuit also includes multiple amplitude modulators that modulate the amplitude of the optical signal output from a portion of the multiple Mach-Zehnder interferometers and input the amplitude-modulated optical signal into another portion of the multiple Mach-Zehnder interferometers. [5] The optical circuit according to any one of [1] to [4] further comprises: a first connection object addition unit, wherein the first connection object addition unit adds a type of connection object that can be switched by the first switching unit; and a second connection object addition unit, wherein the second connection object addition unit adds a type of connection object that can be switched by the second switching unit. [6] According to the optical circuit described in [5], the first connection object addition unit has one or more Mach-Zehnder interferometers that are connected to a portion or all of the M Mach-Zehnder interferometers respectively, and the second connection object addition unit has one or more Mach-Zehnder interferometers that are connected to a portion or all of the L Mach-Zehnder interferometers respectively. [7] According to any one of [1] to [6], in the case where the two connection objects switched by the second switching unit as connection objects of the L Mach-Zehnder interferometers are output objects of optical signals, the two connection objects switched by the first switching unit as connection objects of the M Mach-Zehnder interferometers are signal sources of optical signals, and in the case where the two connection objects switched by the first switching unit as connection objects of the M Mach-Zehnder interferometers are output objects of optical signals, the two connection objects switched by the second switching unit as connection objects of the L Mach-Zehnder interferometers are signal sources of optical signals. [8] According to any one of [1] to [7], the optical circuit wherein the first switching unit and the second switching unit switch the connection object based on a control signal, the control signal including information indicating the purpose of the optical switching circuit, and the N×N Mach-Zehnder interferometers switch operations according to the control signal.

[0120] The embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, the specific structure is not limited to this embodiment. As long as it does not depart from the spirit of this disclosure, changes, substitutions, deletions, etc., can be made.

[0121] Explanation of reference numerals in the attached figures 1… Optical circuit, 10… Optical switch circuit, 11… First switching unit, 12… Second switching unit, 13… First connection object addition unit, 14… Second connection object addition unit, A, A1 to A16… First connection object switching Mach-Zehnder interferometer, AS… Amplitude modulator, B, B1 to B16… Second connection object switching Mach-Zehnder interferometer, C1 to C7… Mach-Zehnder interferometer, CS… Cross waveguide, D1 to D14… Mach-Zehnder interferometer, M11 to M18, M21 to M28, M31 to M38, M41 to M48, M51 to M58, M61 to M68, M71 to M78, M81 to M88… Mach-Zehnder interferometer.

Claims

1. An optical circuit, comprising: An optical switching circuit, the optical switching circuit comprising N×N Mach-Zehnder interferometers configured in an N-row N-column matrix, where N is an integer greater than or equal to 8; A first switching unit switches the connection objects of each of the M Mach-Zehnder interferometers among the N Mach-Zehnder interferometers in the first column of the matrix composed of the N×N Mach-Zehnder interferometers with external connections; where M is any integer greater than or equal to 1 and less than or equal to N; and The second switching unit switches the connection objects of each of the L Mach-Zehnder interferometers among the N Mach-Zehnder interferometers included in the Nth column of the matrix with external objects, where L is any integer greater than 1 and less than N.

2. The optical circuit according to claim 1, wherein, The N×N Mach-Zehnder interferometers each have a first port and a second port, which are located on the side facing from the Nth column of the matrix toward the first row of the first column of the matrix, and are capable of inputting and outputting optical signals. In addition, there are a third port and a fourth port, which are located on the side facing from the first column of the matrix towards the second row of the Nth column, and are capable of inputting and outputting optical signals. The first switching unit switches some or all of the connection objects of the first port and the second port of each of the M Mach-Zehnder interferometers. The second switching unit switches some or all of the connection objects of the third port of each of the L Mach-Zehnder interferometers and the fourth port of each of the M Mach-Zehnder interferometers.

3. The optical circuit according to claim 2, wherein, The first switching unit includes one or more Mach-Zehnder interferometers capable of switching some or all of the connection objects of the first port of each of the M Mach-Zehnder interferometers and the second port of each of the M Mach-Zehnder interferometers. The second switching unit includes one or more Mach-Zehnder interferometers that can switch some or all of the connection objects of the third port and the fourth port of each of the L Mach-Zehnder interferometers.

4. The optical circuit according to claim 3, wherein, The second switching unit includes multiple Mach-Zehnder interferometers that can switch some or all of the connection objects of the third port and the fourth port of each of the L Mach-Zehnder interferometers. The optical circuit also includes multiple amplitude modulators, which modulate the amplitude of the optical signal output from a portion of the multiple Mach-Zehnder interferometers and input the modulated optical signal into another portion of the multiple Mach-Zehnder interferometers.

5. The optical circuit according to claim 1, further comprising: a first connection object addition unit, wherein the first connection object addition unit adds a type of connection object that can be switched by the first switching unit; and a second connection object addition unit, wherein the second connection object addition unit adds a type of connection object that can be switched by the second switching unit.

6. The optical circuit according to claim 5, wherein, The first connection object addition unit includes one or more Mach-Zehnder interferometers that are connected to a portion or all of the M Mach-Zehnder interferometers. The second connection object addition unit includes one or more Mach-Zehnder interferometers that are connected to some or all of the L Mach-Zehnder interferometers respectively.

7. The optical circuit according to claim 1, wherein, When the two connection objects switched by the second switching unit as connection objects of the L Mach-Zehnder interferometers are output objects of optical signals, and the two connection objects switched by the first switching unit as connection objects of the M Mach-Zehnder interferometers are signal sources of optical signals... When the two connection objects switched by the first switching unit as connection objects of the M Mach-Zehnder interferometers are output objects of optical signals, the two connection objects switched by the second switching unit as connection objects of the L Mach-Zehnder interferometers are signal sources of optical signals.

8. The optical circuit according to claim 1, wherein, The first switching unit and the second switching unit switch the connection object based on a control signal, the control signal including information indicating the purpose of the optical switch circuit. The N×N Mach-Zehnder interferometers switch their actions according to the control signal.

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