Optical computing device, optical computing method, and method for manufacturing an optical computing device

Abstract

In order to implement an optical operation device which can execute a bidirectional optical operation, this optical operation device (1) comprises an optical modulation element group (11) composed of one or more optical modulation elements (11a1, 11a2, …). The optical modulation element group (11) is configured to perform a predetermined first optical operation on first signal light (L1) that travels along a specific optical path (P), and perform a predetermined second optical operation on second signal light (L2) that travels inversely to the first signal light (L1) along the specific optical path (P).

Description

Technical Field

[0001] The present invention relates to an optical computing device including an optical modulation element group, an optical computing method using the optical modulation element group, and a method for manufacturing such an optical computing device.

Background Art

[0002] There is known an optical modulation element designed to optically perform a predetermined operation by having a plurality of cells and causing signal lights transmitted through the respective cells to interfere with each other. Such optical operations using such optical modulation elements have the advantages of being faster and consuming less power compared to electrical operations using a processor. Further, by sequentially causing two or more optically modulation elements arranged side by side to act on the signal light, a multi-stage optical operation can be realized.

[0003] Patent Document 1 discloses an optical neural network having an input layer, an intermediate layer, and an output layer. The above-described optical modulation element can be used, for example, as the intermediate layer of such an optical neural network.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Conventional optical computing devices were configured to perform a predetermined optical operation when signal light was input to the optical modulation element group from a specific direction. For this reason, in conventional optical computing devices, there was a problem that even when signal light was input to the optical modulation element group from a direction opposite to the specific direction, a meaningful optical operation could not be performed.

[0006] One aspect of the present invention has been made in view of the above problems, and an object thereof is to realize an optical arithmetic device and an optical arithmetic method capable of performing meaningful optical arithmetic both when signal light is input to an optical modulation element group from a specific direction and when signal light is input to the optical modulation element group from a direction opposite to the specific direction.

Means for Solving the Problems

[0007] The optical arithmetic device according to one aspect of the present invention includes an optical modulation element group composed of at least one optical modulation element, and the optical modulation element group performs a predetermined first optical arithmetic on a first signal light traveling along a specific optical path, and is configured to perform a predetermined second optical arithmetic on a second signal light traveling in a direction opposite to the first signal light along the specific optical path.

Effects of the Invention

[0008] According to one aspect of the present invention, it is possible to realize an optical arithmetic device and an optical arithmetic method capable of performing meaningful optical arithmetic both when signal light is input to an optical modulation element group from a specific direction and when signal light is input to the optical modulation element group from a direction opposite to the specific direction.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

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Embodiment for Carrying Out the Invention

[0010] 〔First Embodiment〕 (Basic Configuration of Optical Computing Device) The basic configuration of the optical computing device 1 according to the first embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 is a side view of the optical computing device 1.

[0011] As shown in FIG. 1, the optical computing device 1 includes an optical modulation element group 11. The optical modulation element group 11 is a set of n optical modulation elements 11a1 to 11an. Here, n is an arbitrary natural number of 1 or more. In FIG. 1, the case of n = 4 is illustrated.

[0012] Each optical modulation element 11ai belonging to the optical modulation element group 11 is an element having an optical computing function, that is, a function of converting the two-dimensional intensity distribution of the signal light according to a predetermined conversion rule. Here, i is each natural number from 1 to n. In the present embodiment, a transmissive optical modulation element is used as each optical modulation element 11ai. For this reason, the two-dimensional intensity distribution of the signal light transmitted through each optical modulation element 11ai becomes the above-described converted two-dimensional intensity distribution. Specific examples of each optical modulation element 11ai will be described later.

[0013] The first signal light L1 and the second signal light L2 are input to the optical modulation element group 11. The first signal light L1 is a signal light traveling in the forward direction along the optical path P, and the second signal light L2 is a signal light traveling in the reverse direction along the optical path P. In the present embodiment, the optical path P is a linear optical path passing through each optical modulation element 11ai included in the optical modulation element group 11.

[0014] The first signal light L1 passes through the first optical modulation element 11a1, the second optical modulation element 11a2, …, the (n−1)th optical modulation element 11an−1, and the nth optical modulation element 11an in this order. Therefore, in the optical modulation element group 11, for the first signal light L1, the optical operation f = fn·fn−1·…·f2·f1, which is the synthesis of the optical operation f1 by the first optical modulation element 11a1, the optical operation f2 by the second optical modulation element 11a2, …, the optical operation fn−1 by the (n−1)th optical modulation element 11an−1, and the optical operation fn by the nth optical modulation element 11an, is executed. For this reason, the two-dimensional intensity distribution of the first signal light L1 output from the optical modulation element group 11 represents the result f(L1)=fn(fn−1(…(f2(f1(L1)))…)) of this optical operation f. This optical operation f is hereinafter also referred to as the forward optical operation f.

[0015] The second signal light L2 passes through the nth optical modulation element 11an, the (n−1)th optical modulation element 11an−1, …, the second optical modulation element 11a2, and the first optical modulation element 11a1 in this order. Therefore, in the optical modulation element group 11, for the second signal light L2, the optical operation g = g1·g2·…·gn−1·gn, which is the synthesis of the optical operation gn by the nth optical modulation element 11an, the optical operation gn−1 by the (n−1)th optical modulation element 11an−1, …, the optical operation g2 by the second optical modulation element 11a2, and the optical operation g1 by the first optical modulation element 11a1, is executed. For this reason, the two-dimensional intensity distribution of the second signal light L2 output from the optical modulation element group 11 represents the result g(L2)=g1(g2(…(gn−1(gn(L2)))…)) of this optical operation g. This optical operation g is hereinafter also referred to as the reverse optical operation g.

[0016] Each optical modulation element 11ai belonging to the optical modulation element group 11 is designed such that the forward optical operation f = fn·fn-1·…, f2·f1 coincides with a predetermined first optical operation, and the reverse optical operation g = g1·g2·…, gn-1·gn coincides with a predetermined second optical operation. The forward optical operation f and the reverse optical operation g may be the same optical operation or different optical operations. When the forward optical operation f and the reverse optical operation g are the same optical operation, a bidirectional optical operation device 1 that can obtain the same operation result can be realized whether the signal light is input from the side of the first optical modulation element 11a1 or from the side of the nth optical modulation element 11an. On the other hand, when the forward optical operation f and the reverse optical operation g are different optical operations, an optical operation device 1 that can obtain different operation results can be realized depending on whether the signal light is input from the side of the first optical modulation element 11a1 or from the side of the nth optical modulation element 11an.

[0017] In addition, when each optical modulation element 11ai is configured symmetrically with respect to a plane orthogonal to the straight line including the optical path P, the optical operation fi for the first signal light L1 and the optical operation gi for the second signal light L2 are the same optical operation. However, even in this case, if n is 2 or more, the forward optical operation f and the reverse optical operation g can be different optical operations. This is because the optical operations f1 = g1, f2 = g2, …, fn-1 = gn-1, and fn = gn are not commutative.

[0018] The first signal light L1 and the second signal light L2 may be signal lights having the same wavelength as each other or signal lights having different wavelengths from each other. When the wavelengths of the first signal light L1 and the second signal light L2 are different, it becomes easy to make the forward optical operation f coincide with a predetermined first optical operation and the reverse optical operation g coincide with a predetermined second optical operation. This is because the influence of the first signal light L1 on the second signal light L2 and the influence of the second signal light L2 on the first signal light L1 can be reduced respectively.

[0019] Further, the first signal light L1 and the second signal light L2 may be signal lights with the same polarization direction or signal lights with different polarization directions. When the polarization directions of the first signal light L1 and the second signal light L2 are different, it becomes easier to match the forward light operation f with a predetermined first light operation and to match the backward light operation g with a predetermined second light operation. This is because the influence of the first signal light L1 on the second signal light L2 and the influence of the second signal light L2 on the first signal light L1 can be reduced respectively.

[0020] Also, the first signal light L1 and the second signal light L2 may be signal lights with the same coherence length or signal lights with different coherence lengths. When the coherence lengths of the first signal light L1 and the second signal light L2 are different, it becomes easier to match the forward light operation f with a predetermined first light operation and to match the backward light operation g with a predetermined second light operation. This is because the influence of the first signal light L1 on the second signal light L2 and the influence of the second signal light L2 on the first signal light L1 can be reduced respectively.

[0021] (Additional Configuration of Optical Operation Device) The additional configuration of the optical operation device 1 will be described below with continued reference to FIG. 1.

[0022] As shown in FIG. 1, the optical operation device 1 preferably further includes a first light emitting device 121 that generates the first signal light L1 before performing the forward light operation f, and a second light emitting device 122 that generates the second signal light L2 before performing the backward light operation g. Thereby, bidirectional optical operations can be realized without using an external light emitting device. When using an external light emitting device, it is also possible to omit one or both of the first light emitting device 121 and the second light emitting device 122.

[0023] Note that, as the first light emitting device 121 and the second light emitting device 122, for example, a two-dimensional display including a plurality of light emitting cells arranged in a matrix can be used.

[0024] Further, as shown in FIG. 1, the optical computing device 1 preferably further includes a first light receiving device 131 that detects the first signal light L1 after performing the forward optical computation f, and a second light receiving device 132 that detects the second signal light L2 after performing the reverse optical computation g. Thereby, two-way optical computation can be realized without using an external light receiving device. When using an external light receiving device, one or both of the first light receiving device 131 and the second light receiving device 132 can be omitted.

[0025] Note that, as the first light receiving device 131 and the second light receiving device 132, for example, a two-dimensional image sensor including light receiving cells arranged in a matrix can be used.

[0026] Further, as shown in FIG. 1, the optical computing device 1 preferably includes a first optical element 141 that branches one optical path of the first signal light L1 before performing the forward optical computation f or the second signal light L2 after performing the reverse optical computation g from the above-described optical path P. In FIG. 1, as the first optical element 141, an optical element that branches the optical path of the second signal light L2 after performing the reverse optical computation g from the above-described optical path P is illustrated. Thereby, the first light emitting device 121 and the second light receiving device 132 can be arranged at different locations, and as a result, the mounting of the optical computing device 1 becomes easy.

[0027] Note that when the wavelengths of the first signal light L1 and the second signal light L2 are different, as the first optical element 141, for example, a beam splitter having wavelength selectivity that transmits one of the first signal light L1 and the second signal light L2 and reflects the other can be used. Further, when the polarization directions of the first signal light L1 and the second signal light L2 are different, as the first optical element 141, for example, a beam splitter having polarization direction selectivity that transmits one of the first signal light L1 and the second signal light L2 and reflects the other can be used.

[0028] Further, as shown in FIG. 1, the optical computing device 1 preferably includes a second optical element 142 that branches one optical path of the second signal light L2 before performing the reverse optical computation g or the first signal light L1 after performing the forward optical computation f from the above-described optical path P. In FIG. 1, as the second optical element 142, an optical element that branches the optical path of the first signal light L1 after performing the forward optical computation f from the above-described optical path P is illustrated. Thereby, the second light emitting device 122 and the first light receiving device 131 can be arranged at different locations, and as a result, the mounting of the optical computing device 1 becomes easy.

[0029] When the wavelengths of the first signal light L1 and the second signal light L2 are different, as the second optical element 142, for example, a wavelength-selective beam splitter that transmits one of the first signal light L1 and the second signal light L2 and reflects the other can be used. When the polarization directions of the first signal light L1 and the second signal light L2 are different, as the second optical element 142, for example, a polarization-direction-selective beam splitter that transmits one of the first signal light L1 and the second signal light L2 and reflects the other can be used.

[0030] (Specific Example of Optical Modulation Element) A specific example of the optical modulation element 11ai will be described with reference to FIGS. 2 and 3. FIG. 2 is a plan view of the optical modulation element 11ai according to the present specific example. FIG. 3 is an enlarged perspective view of a part (a part surrounded by a dotted line in FIG. 2) of the optical modulation element 11ai according to the present specific example.

[0031] As shown in Fig. 2, the optical modulation element 11ai is composed of a plurality of microcells C whose thicknesses or refractive indices are set independently of each other. When signal light is incident on the optical modulation element 11ai, signal lights with different phases diffracted by each microcell C interfere with each other, and a predetermined optical operation (conversion of a two-dimensional intensity distribution according to a predetermined conversion rule) is performed. Here, the "microcell" refers to, for example, a cell with a cell size of less than 10 μm. Also, the "cell size" refers to the square root of the area of the cell. For example, when the planar shape of the microcell C is square, the cell size of the microcell C is the length of one side of the microcell C. The lower limit of the cell size of the microcell C is, for example, 1 nm.

[0032] The optical modulation element 11ai illustrated in Fig. 2 is composed of 200×200 microcells C arranged in a matrix. The planar shape of each microcell C is a square of 500 nm×500 nm, and the planar shape of the optical modulation element 11ai is a square of 100 μm×100 μm.

[0033] (1) By independently setting the thickness of each microcell C, or (2) by independently selecting the refractive index of each microcell C, the amount of phase change of the signal light transmitted through each microcell C can be independently set for each cell. In the present embodiment, the method (1) that can be realized by nanoimprint is adopted. In this case, as shown in Fig. 3, each microcell C is composed of a columnar pillar P having a square bottom surface with the length of each side equal to the cell size. Also, in this case, the amount of phase change of the signal light transmitted through each microcell C is determined according to the height of the pillar P that constitutes the microcell C. That is, the amount of phase change of the signal light transmitted through the microcell C composed of the pillar P with a high height becomes large, and the amount of phase change of the signal light transmitted through the microcell C composed of the pillar with a low height becomes small.

[0034] As shown in FIG. 3, pillars P are arranged on a transparent substrate C10. At this time, either the transparent substrate C10 side or the pillar P side can be the light incident surface of the optical modulation element 11ai. Regardless of which of these is the incident surface, the signal lights with different phases diffracted by each microcell C (pillar P) interfere with each other, and a predetermined optical operation is performed.

[0035] When the wavelength of the first signal light L1 is different from the wavelength of the second signal light L2, it is preferable that the optical modulation element Ci is composed of a cell that mainly acts on the first signal light (for example, a cell whose cell size is adapted to the wavelength of the first signal light L1) and a cell that mainly acts on the second signal light (for example, a cell whose cell size is adapted to the wavelength of the second signal light L2). Thereby, it becomes easier to match the forward optical operation f with a predetermined first optical operation and to match the reverse optical operation g with a predetermined second optical operation.

[0036] When the polarization direction of the first signal light L1 is different from the polarization direction of the second signal light L2, it is preferable that the optical modulation element Ci is composed of a cell that mainly acts on the first signal light (for example, a cell whose longitudinal direction is adapted to the polarization direction of the first signal light L1) and a cell that mainly acts on the second signal light (for example, a cell whose longitudinal direction is adapted to the polarization direction of the second signal light L2). Thereby, it becomes easier to match the forward optical operation f with a predetermined first optical operation and to match the reverse optical operation g with a predetermined second optical operation.

[0037] Incidentally, the setting of the thickness or refractive index of each microcell C can be realized, for example, using machine learning. As a model used in this machine learning, for example, a model that takes the two-dimensional intensity distribution of the signal light input to the optical modulation element 11ai as an input and outputs the two-dimensional intensity distribution of the signal light output from the optical modulation element 11ai, and includes the thickness or refractive index of each microcell C as a parameter can be used. Here, the two-dimensional intensity distribution of the signal light input to the optical modulation element 11ai refers to the set of the intensities of the signal light input to each microcell C constituting the optical modulation element 11ai. Also, the two-dimensional intensity distribution of the signal light output from the optical modulation element 11ai refers to the set of the intensities of the signal light input to each microcell C constituting the optical modulation element 11ai+1 arranged downstream of the optical modulation element 11ai, or the set of the intensities of the signal light input to each cell constituting the light receiving device arranged downstream of the optical modulation element 11ai.

[0038] [Second Embodiment] (Basic Configuration of Optical Computing Device) The basic configuration of the optical computing device 2 according to the second embodiment of the present invention will be described with reference to FIG. 4. FIG. 4 is a side view of the optical computing device 2.

[0039] As shown in FIG. 4, the optical computing device 2 includes an optical modulation element group 21. The optical modulation element group 21 is a set of n optical modulation elements 21a1 to 21an. Here, n is an arbitrary natural number of 1 or more. In FIG. 4, the case of n = 4 is illustrated.

[0040] Each optical modulation element 21ai belonging to the optical modulation element group 21 is an element having an optical computing function, that is, a function of converting the two-dimensional intensity distribution of the signal light according to a predetermined conversion rule. Here, i is each natural number from 1 to n. In the present embodiment, a reflective optical modulation element is used as each optical modulation element 21ai. For this reason, the two-dimensional intensity distribution of the signal light reflected by each optical modulation element 21ai becomes the above-described converted two-dimensional intensity distribution. Specific examples of each optical modulation element 21ai will be described later.

[0041] The first signal light L1 and the second signal light L2 are input to the optical modulation element group 21. The first signal light L1 is a signal light that travels in the forward direction along the optical path P, and the second signal light L2 is a signal light that travels in the reverse direction along the optical path P. In the present embodiment, the optical path P is a polygonal line-shaped optical path passing through each optical modulation element 21ai included in the optical modulation element group 21.

[0042] The first signal light L1 is reflected by the first optical modulation element 21a1, the second optical modulation element 21a2,..., the (n - 1)-th optical modulation element 21an-1, and the n-th optical modulation element 21an in this order. Therefore, in the optical modulation element group 21, for the first signal light L1, the optical operation f1 by the first optical modulation element 21a1, the optical operation f2 by the second optical modulation element 21a2,..., the optical operation fn-1 by the (n - 1)-th optical modulation element 21an-1, and the optical operation fn by the n-th optical modulation element 21an are combined to execute an optical operation f = fn·fn-1·…,f2·f1. For this reason, the two-dimensional intensity distribution of the first signal light L1 output from the optical modulation element group 21 represents the result f(L1) = fn(fn-1(…(f2(f1(L1)))…)) of this optical operation f. This optical operation f is hereinafter also referred to as the forward optical operation f.

[0043] The second signal light L2 is reflected by the n-th optical modulation element 21an, the (n - 1)-th optical modulation element 21an-1,..., the second optical modulation element 21a2, and the first optical modulation element 21a1 in this order. Therefore, in the optical modulation element group 21, for the second signal light L2, the optical operation gn by the n-th optical modulation element 21an, the optical operation gn-1 by the (n - 1)-th optical modulation element 21an-1,..., the optical operation g2 by the second optical modulation element 21a2, and the optical operation g1 by the first optical modulation element 21a1 are combined to execute an optical operation g = g1·g2·…,gn-1·gn. For this reason, the two-dimensional intensity distribution of the second signal light L2 output from the optical modulation element group 21 represents the result g(L2) = g1(g2(…(gn-1(gn(L2)))…)) of this optical operation g. This optical operation g is hereinafter also referred to as the reverse optical operation g.

[0044] Each optical modulation element 21ai belonging to the optical modulation element group 21 is designed such that the forward optical operation f = fn·fn-1·…,f2·f1 matches a predetermined first optical operation and the reverse optical operation g = g1·g2·…,gn-1·gn matches a predetermined second optical operation. The forward optical operation f and the reverse optical operation g may be the same optical operation or different optical operations. When the forward optical operation f and the reverse optical operation g are the same optical operation, a bidirectional optical operation device 2 that can obtain the same operation result can be realized whether the signal light is input from the side of the first optical modulation element 21a1 or from the side of the nth optical modulation element 21an. On the other hand, when the forward optical operation f and the reverse optical operation g are different optical operations, an optical operation device 2 that can obtain different operation results can be realized depending on whether the signal light is input from the side of the first optical modulation element 21a1 or from the side of the nth optical modulation element 21an.

[0045] In addition, when each optical modulation element 21ai is configured symmetrically with respect to a plane orthogonal to the plane including the optical path P, the optical operation fi on the first signal light L1 and the optical operation gi on the second signal light L2 are the same optical operation. However, even in this case, if n is 2 or more, the forward optical operation f and the reverse optical operation g can be different optical operations. This is because the optical operations f1 = g1, f2 = g2, …, fn-1 = gn-1, fn = gn are not commutative.

[0046] The first signal light L1 and the second signal light L2 may be signal lights with equal wavelengths or signal lights with different wavelengths. When the wavelengths of the first signal light L1 and the second signal light L2 are different, it becomes easy to match the forward optical operation f to a predetermined first optical operation and the reverse optical operation g to a predetermined second optical operation. This is because the influence of the first signal light L1 on the second signal light L2 and the influence of the second signal light L2 on the first signal light L1 can be reduced respectively.

[0047] In addition, the first signal light L1 and the second signal light L2 may be signal lights with the same polarization direction, or may be signal lights with different polarization directions. When the polarization directions of the first signal light L1 and the second signal light L2 are different, it becomes easy to match the forward light operation f with a predetermined first light operation and match the backward light operation g with a predetermined second light operation. This is because the influence of the first signal light L1 on the second signal light L2 and the influence of the second signal light L2 on the first signal light L1 can be reduced respectively.

[0048] In addition, the first signal light L1 and the second signal light L2 may be signal lights with the same coherence length, or may be signal lights with different coherence lengths. When the coherence lengths of the first signal light L1 and the second signal light L2 are different, it becomes easy to match the forward light operation f with a predetermined first light operation and match the backward light operation g with a predetermined second light operation. This is because the influence of the first signal light L1 on the second signal light L2 and the influence of the second signal light L2 on the first signal light L1 can be reduced respectively.

[0049] Note that it is preferable that the odd-numbered optical modulation elements 21a1, 21a3,... are integrally formed on a single substrate. Thereby, adjustment of the relative positions of the odd-numbered optical modulation elements 21a1, 21a3,... can be made unnecessary. Also, it is preferable that the even-numbered optical modulation elements 21a2, 21a4,... are integrally formed on a single substrate. Thereby, adjustment of the relative positions of the even-numbered optical modulation elements 21a2, 21a4,... can be made unnecessary.

[0050] (Additional Configuration of Optical Computing Device) The additional configuration of the optical computing device 2 will be continuously described with reference to FIG. 4.

[0051] As shown in FIG. 4, the optical computing device 2 preferably further includes a first light emitting device 221 that generates a first signal light L1 before performing the forward optical operation f, and a second light emitting device 222 that generates a second signal light L2 before performing the reverse optical operation g. Thereby, a bidirectional optical operation can be realized without using an external light emitting device. When using an external light emitting device, it is also possible to omit one or both of the first light emitting device 221 and the second light emitting device 222.

[0052] Note that, as the first light emitting device 221 and the second light emitting device 222, for example, a two-dimensional display including a plurality of light emitting cells arranged in a matrix can be used.

[0053] As shown in FIG. 4, the optical computing device 2 preferably further includes a first light receiving device 231 that detects the first signal light L1 after performing the forward optical operation f, and a second light receiving device 232 that detects the second signal light L2 after performing the reverse optical operation g. Thereby, a bidirectional optical operation can be realized without using an external light receiving device. When using an external light receiving device, it is also possible to omit one or both of the first light receiving device 231 and the second light receiving device 232.

[0054] Note that, as the first light receiving device 231 and the second light receiving device 232, for example, a two-dimensional image sensor including light receiving cells arranged in a matrix can be used.

[0055] As shown in FIG. 4, the optical computing device 2 preferably includes a first optical element 241 that branches one optical path of the first signal light L1 before performing the forward optical operation f or the second signal light L2 after performing the reverse optical operation g from the above-described optical path P. In FIG. 4, as the first optical element 241, an optical element that branches the optical path of the second signal light L2 after performing the reverse optical operation g from the above-described optical path P is illustrated. Thereby, it becomes possible to arrange the first light emitting device 221 and the second light receiving device 232 at different locations, and as a result, the mounting of the optical computing device 2 becomes easy.

[0056] In addition, when the wavelengths of the first signal light L1 and the second signal light L2 are different, as the first optical element 241, for example, a beam splitter having wavelength selectivity that transmits one of the first signal light L1 and the second signal light L2 and reflects the other can be used. Further, when the polarization directions of the first signal light L1 and the second signal light L2 are different, as the first optical element 241, for example, a beam splitter having polarization direction selectivity that transmits one of the first signal light L1 and the second signal light L2 and reflects the other can be used.

[0057] Further, as shown in FIG. 4, it is preferable that the optical arithmetic device 2 includes a second optical element 242 that branches one optical path of the second signal light L2 before performing the reverse-direction optical arithmetic g or the first signal light L1 after performing the forward-direction optical arithmetic f from the above-described optical path P. In FIG. 4, as the second optical element 242, an optical element that branches the optical path of the first signal light L1 after performing the forward-direction optical arithmetic f from the above-described optical path P is illustrated. Thereby, the second light-emitting device 222 and the first light-receiving device 231 can be arranged at different locations, and as a result, the mounting of the optical arithmetic device 2 becomes easy.

[0058] In addition, when the wavelengths of the first signal light L1 and the second signal light L2 are different, as the second optical element 242, for example, a beam splitter having wavelength selectivity that transmits one of the first signal light L1 and the second signal light L2 and reflects the other can be used. Further, when the polarization directions of the first signal light L1 and the second signal light L2 are different, as the second optical element 242, for example, a beam splitter having polarization direction selectivity that transmits one of the first signal light L1 and the second signal light L2 and reflects the other can be used.

[0059] (Specific example of the optical modulation element) A specific example of the optical modulation element 21ai will be described with reference to FIGS. 5 and 6. FIG. 5 is a plan view of the optical modulation element 21ai according to the present specific example. FIG. 6 is a cross-sectional view of the microcell C constituting the optical modulation element 21ai according to the present specific example.

[0060] As shown in FIG. 5, the optical modulation element 21ai is composed of a plurality of microcells C in which the phase modulation amounts (phase change amounts) are set independently of each other. When signal light is incident on the optical modulation element 21ai, signal lights with different phases modulated and reflected by each microcell C interfere with each other, and a predetermined optical operation (conversion of a two-dimensional intensity distribution according to a predetermined conversion rule) is performed. Here, the "microcell" refers to, for example, a cell with a cell size of less than 10 μm. Also, the "cell size" refers to the square root of the area of the cell. For example, when the planar shape of the microcell C is square, the cell size of the microcell C is the length of one side of the microcell C. The lower limit of the cell size of the microcell C is, for example, 1 nm.

[0061] The optical modulation element 21ai illustrated in FIG. 5 is composed of 200×200 microcells arranged in a matrix. The planar shape of each microcell is a square of 500 nm×500 nm, and the planar shape of the optical modulation element 21ai is a square of 100 μm×100 μm.

[0062] As shown in FIG. 6, the microcell C includes a polarizing plate C11, a substrate C12, a block C13, a spacer layer C14, a magnetization fixing layer C15, an electrode C16, and an electrode C17. In the following description, among the normal directions of the optically effective surface C133 of the block C13, the direction from the optically effective surface C133 toward the outside of the block C13 is defined as the positive x-axis direction. Also, among the normal directions of the surface C131 and the surface C132 of the block C13, the direction from the surface C131 toward the surface 132 is defined as the positive z-axis direction. Also, the direction that constitutes a right-handed orthogonal coordinate system together with the positive x-axis direction and the positive z-axis direction is defined as the positive y-axis direction.

[0063] In the microcell C, the incident light Lin is incident on the optically effective surface C133 from a direction inclined by the incident angle in the positive z-axis direction from the x-axis direction perpendicular to the optically effective surface C133. Note that a polarizing plate C11 is provided in front of the block C13 as viewed from the incident light Lin. The light incident on the optically effective surface C133 propagates inside the block C13 in the direction toward the substrate C12 (approximately the negative x-axis direction), is reflected at the interface between the block C13 and the substrate C12, and then propagates inside the block C13 in the direction toward the optically effective surface C133 (approximately the positive x-axis direction), and is emitted as light L12 from the optically effective surface C133. The light L12 is emitted from the optically effective surface C133 in a direction inclined by the emission angle corresponding to the incident angle in the negative z-axis direction from the x-axis direction perpendicular to the optically effective surface C133. Note that in FIG. 6, the illustration of the optical path inside the block C13 is omitted. In this specific example, the incident angle and the emission angle are 10°. However, the incident angle and the emission angle are not limited to 10° and can be determined as appropriate.

[0064] The substrate C12 is a plate-like member configured such that the main surface (the main surface on the positive x-axis side) in contact with the block C13 reflects light specularly. The material of the substrate C12 is not particularly limited, but at least the main surface is made of a material that reflects light. The main surface is preferably configured to be flat in order to reflect light specularly. In this specific example, quartz glass with a thin aluminum film formed on the main surface is employed as the substrate C12. However, the reflecting member is not limited to aluminum and may be a metal film other than aluminum or a dielectric multilayer film. Further, the substrate C12 is not limited to this and may be a plate-like member made of metal or semiconductor finished such that the main surface becomes a mirror surface. Examples of the metal constituting the substrate C12 include aluminum and copper, and an example of the semiconductor is silicon. The reflecting surface C134 of the block C13 is fixed to the main surface on the positive x-axis side of the substrate C12. In this specific example, a resin is used as the fixing member for fixing the substrate C12 and the block C13. However, this fixing member is not limited to this.

[0065] Block C13 is made of a material that is transparent to the incident light Lin. Also, block C13 contains magnetic atoms. The magnetization state of block C13 is not fixed. Therefore, block C13 may be made of a material that can be easily changed in magnetic susceptibility by spin injection. As the material constituting block C13, various materials such as paramagnets and ferromagnets can be used. In order to achieve a higher magnetic susceptibility, it is preferably configured to exhibit ferromagnetism at room temperature (for example, 25°C), and a ferromagnet with a relatively high spin polarization rate is preferably used. The spin polarization rate is preferably, for example, 50% or more. In this specific example, CoFeB is adopted as the material constituting block C13. However, it is not limited to this, and CoFe, NiFe, Fe, Ni, Co, etc. can also be preferably used. Also, it is not necessary to be a block composed of a single composition, and an insulator (for example, alumina or glass) added with the above-mentioned fine particles can also be adopted.

[0066] Note that, as will be described later, the magnetization fixing layer C15 is also made of a material that exhibits ferromagnetism (more specifically, hard magnetism). Here, the coercive force of block C13 is smaller than that of the magnetization fixing layer C15. Thereby, the direction of the magnetization M13 of block C13 can be changed while the direction of the magnetization M15 in the magnetization fixing layer C15 is fixed. The magnetization M13 can take the same direction as or the opposite direction to the magnetization M15 among the directions parallel or substantially parallel to the magnetization M15.

[0067] In this specific example, CoFeB, which is adopted as the material of block C13, is an example of a ferromagnetic material (i.e., a soft magnetic material) with sufficiently small coercive force and residual magnetization at room temperature. The material of block C13 is not limited to soft magnetic materials. However, by using a soft magnetic material to form block C13, the residual magnetization remaining in block C13 when the injection of polarized electrons is stopped becomes sufficiently small compared to the saturation magnetization at room temperature. Therefore, when using volatile block C13, it is preferable to use a ferromagnetic material whose residual magnetization at room temperature is sufficiently small compared to the saturation magnetization at room temperature as the material of block C13. Here, the residual magnetization at room temperature being sufficiently small compared to the saturation magnetization at room temperature means, for example, that the residual magnetization at room temperature is 0% or more and less than 10% with respect to the saturation magnetization at room temperature. According to this configuration, when spin-polarized electrons are injected into block C13, a magnetic interaction occurs between the magnetic atoms contained in block C13, and magnetization M13 is generated. Also, when the injection of spin-polarized electrons into block C13 is stopped, the interaction acting between the magnetic atoms contained in block C13 disappears, and magnetization M13 also disappears. Therefore, according to this configuration, magnetization M13 can be volatilely generated or disappeared by using the injection of spin-polarized electrons. As a result, microcell C can control the degree of phase delay in the component of the light propagating inside block C13 whose polarization plane is parallel to the zx plane.

[0068] Note that a ferromagnetic material (i.e., a hard magnetic material) with relatively large residual magnetization at room temperature compared to the saturation magnetization at room temperature may be used for block C13. Here, the residual magnetization at room temperature being relatively large compared to the saturation magnetization at room temperature means, for example, that the residual magnetization at room temperature is 90% or more and 100% or less with respect to the saturation magnetization at room temperature. According to this configuration, the magnetization M13 generated by the injection of spin-polarized electrons remains without disappearing after the injection of spin-polarized electrons is stopped. Therefore, when this configuration is adopted, even after the injection of spin-polarized electrons is stopped, the phase in the component whose polarization plane is parallel to the zx plane can be non-volatily delayed.

[0069] In addition, in this specific example, the ratio of the residual magnetization at room temperature to the saturation magnetization at room temperature in the material constituting block C13 is not limited to 0% or more and less than 10% or 90% or more and 100% or less, and may be 10% or more and less than 90%.

[0070] Also, when block C13 exhibits paramagnetism, the direction of magnetization M13 can take various directions. However, when spin-polarized electrons are injected into block C13, the magnetization M13 in the macroscopic view is in a direction parallel or substantially parallel to magnetization M15, and takes the same direction or the opposite direction as magnetization M15.

[0071] In this specific example, the shape of block C13 is a rectangular parallelepiped. Therefore, the surface of block C13 is composed of six faces. In block C13, two planes parallel to the xy plane and facing each other are defined as faces C131 and C132. Also, two planes parallel to the yz plane and facing each other are defined as the optically effective face C133 and the reflective face C134. In this specific example, both the optically effective face C133 and the reflective face C134 are flat surfaces (i.e., planes). However, the optically effective face C133 and the reflective face C134 are not limited to planes and may be provided with irregularities. This irregular structure may be a periodic structure or a random structure. By appropriately designing this irregular structure, the reflection loss that may occur on the optically effective face C133 and the reflective face C134 can be reduced.

[0072] The spacer layer C14 is a layered member made of an insulator. The spacer layer C14 is interposed between the block C13 and the magnetization fixing layer C15, which will be described later, and insulates the block C13 and the magnetization fixing layer C15. The spacer layer C14 forms a tunnel junction together with the block C13 and the magnetization fixing layer C15. Therefore, the thickness of the spacer layer C14 can be appropriately determined within the range where current can tunnel. A typical thickness of the spacer layer C14 is 2 nm or more and 3 nm or less. However, the thickness of the spacer layer C14 is not limited to this. In order for the spacer layer C14 to exhibit good tunnel characteristics, it is preferably composed of a film that does not contain pinholes and has a uniform thickness. By using spin-polarized electrons as carriers of the tunnel current, the magnetization of the block C13 can be switched at a lower power and at a higher speed. Thus, the microcell C functions as a spin injection type phase modulator using a tunnel junction.

[0073] In this specific example, aluminum oxide (Al2O3) is adopted as the insulator constituting the spacer layer C14. However, this insulator is not limited to aluminum oxide. As this insulator, for example, an insulator constituting a spacer layer of an MRAM (Magnetoresistive Random Access Memory) can be used. Note that in the microcell C, the spacer layer C14 can also be omitted.

[0074] The magnetization fixing layer C15 is a layered member composed of a ferromagnetic material having conductivity. In this specific example, the magnetization fixing layer C15 is indirectly provided via the spacer layer C14 with respect to the surface C131. However, the magnetization fixing layer C15 may be directly provided with respect to the surface 131. The ferromagnetic material constituting the magnetization fixing layer C15 exhibits ferromagnetism at room temperature. The coercive force of the magnetization fixing layer C15 is larger than the coercive force of the block C13. In this specific example, Permalloy, which is an alloy of nickel and iron, is adopted as the ferromagnetic material constituting the magnetization fixing layer C15. The composition ratio of nickel and iron is not limited, and for example, Ni81Fe19 can be mentioned. Further, this ferromagnetic material is not limited to Permalloy. As this ferromagnetic material, for example, a ferromagnetic material constituting the magnetization fixing layer of MRAM, such as magnesium oxide, can be used. Also, the thickness of the magnetization fixing layer C15 is not limited and can be determined as appropriate.

[0075] The magnetization fixing layer C15 is roughly classified into a perpendicular magnetization type and an in-plane magnetization type according to the direction of the magnetization M15. In the in-plane magnetization type magnetization fixing layer C15, the direction of the magnetization M15 is substantially orthogonal to the traveling direction (x-axis direction) of the incident light Lin among the in-plane directions of the main surface of the magnetization fixing layer C15 as shown in FIG. 6. In the microcell C, an in-plane magnetization type is adopted, and the magnetization fixing layer C15 in which the direction of the magnetization M15 is the negative y-axis direction is used. Since the direction of the magnetization M13 of the block C13 is parallel to the direction of the magnetization M15, the direction of the magnetization M13 is also parallel to the y-axis direction. Also, in the microcell C, a polarizing plate C11 is provided on the optical path of the incident light Lin which is the incident light. The transmission axis A11 of the polarizing plate C11 is oriented parallel to the z-axis direction in the yz plane as shown in FIG. 6. Therefore, the polarizing plate C11 transmits only linearly polarized light whose polarization direction is parallel to the z-axis among the components of the incident light Lin and makes it incident on the optically effective surface C133.

[0076] According to this configuration, the direction of magnetization M13 (z-axis direction) is orthogonal or substantially orthogonal to the polarization direction of the incident light Lin (z-axis direction). Therefore, due to the interaction with the magnetization M13, a transverse Kerr effect occurs in the incident light Lin, and thus the microcell C can emit an output light Lout whose phase is delayed compared to the incident light Lin that propagates parallel to the x-axis direction inside the block C13. That is, the microcell C can delay the phase of the light. Note that the degree to which the block C13 delays the phase of the incident light Lin depends on the magnetic field formed inside the block C13. Therefore, this degree depends on the magnitude of the magnetization M15 and the amount of spin injection into the block C13. Thus, the microcell C can modulate the phase of the incident light.

[0077] The electrodes C16 and C17, which are a pair of electrodes, are both layered members made of a conductor. In this specific example, copper is used as the conductor that constitutes the electrodes C16 and C17. However, this conductor is not limited to copper. This conductor preferably has a high conductivity. Examples of this conductor include silver and gold in addition to copper. The electrode C16 is provided with respect to the surface C131 via the spacer layer C14 and the magnetization fixing layer C15. Therefore, on the surface C131, the spacer layer C14, the magnetization fixing layer C15, and the electrode C16 are laminated in this order. Also, the electrode C17 is provided directly with respect to the surface C132. Thus, the electrodes C16 and C17 are provided so as to face each other, and are arranged in the order of the electrode C16, the magnetization fixing layer C15, the spacer layer C14, and the electrode C17. It can also be said that the electrodes C16 and C17 sandwich the block C13, the spacer layer C14, and the magnetization fixing layer C15. The electrodes C16 and C17 are each an example of a first electrode and a second electrode.

[0078] Electrodes C16 and C17 are each connected to either the positive or negative electrode of a power supply, and a voltage can be applied between the electrodes. By injecting spin-polarized electrons into block C13 using electrodes C16 and C17, block C13 becomes magnetized. Block C13 functions as an optical path for light that propagates from optical effective surface C133, through reflective surface C134, and back towards optical effective surface C133. Therefore, electrodes C16 and C17 can inject spin-polarized electrons into block C13 such that a magnetic field is generated in at least a part of the optical path of the light propagating inside block C13.

[0079] Note that the setting of the phase modulation amount for each microcell C can be realized, for example, using machine learning. As a model used in this machine learning, for example, a model can be used that takes as input the two-dimensional intensity distribution of the signal light input to optical modulator 21ai and outputs the two-dimensional intensity distribution of the signal light output from optical modulator 21ai, and includes the phase modulation amount of each microcell C as a parameter. Here, the two-dimensional intensity distribution of the signal light input to optical modulator 21ai refers to the set of intensities of the signal light input to each microcell C that constitutes optical modulator 21ai. Also, the two-dimensional intensity distribution of the signal light output from optical modulator 21ai refers to the set of intensities of the signal light input to each microcell C that constitutes optical modulator 21ai+1 arranged downstream of optical modulator 21ai, or the set of intensities of the signal light input to each cell that constitutes the light receiving device arranged downstream of optical modulator 21ai.

[0080] 〔Modification Example〕 Hereinafter, modified examples of the embodiments of the present invention will be described. In Embodiment 1 or 2, the plurality of microcells C have been described as "the thickness or refractive index being set independently of each other". In addition to this, the plurality of microcells C may be "able to set the refractive indices independently of each other". For example, the microcell C shown in FIG. 6 can modulate the amount of electrons injected into the block C13, and thus the phase of the incident light, by applying a voltage between the electrodes C16 and C17. This modulation is based on the Kerr effect, and the microcell C can independently change the refractive index, and thus the amount of phase change, according to the voltage between the electrodes C16 and C17.

[0081] The microcell C in FIG. 6 is a reflective type, and reflects the incident light Lin on the reflection surface C134 of the substrate C12 to obtain the output light Lout. On the other hand, the microcell C may be a transmissive type. That is, by replacing the substrate C12 of the microcell C in FIG. 6 with a polarizing plate, a transmissive microcell C can be configured in which the incident light Lin passes through the substrate C12 in the negative X-axis direction to become the output light.

[0082] As described above, the plurality of cells (microcells C) can have the thickness or refractive index set independently of each other, or can have the refractive indices set independently of each other. And these cells are applicable to both the transmissive optical modulation element 11ai and the reflective optical modulation element 21ai.

[0083] When the optical modulation element group 11 includes the optical modulation element 11ai in which the amount of phase change (thickness or refractive index) of each microcell C is variable, the optical arithmetic unit 1 may include a control unit that independently controls the amount of phase change (refractive index) of each microcell C of the optical modulation element 11ai. Thereby, it becomes possible to change the content of the optical arithmetic operation executed by the optical arithmetic unit 1. Note that the same applies even in the case of the reflective optical modulation element 21ai instead of the transmissive optical modulation element 11ai. That is, the optical arithmetic unit 2 may include a control unit that independently controls the amount of phase change (refractive index) of each microcell C of the optical modulation element 21ai.

[0084] The optical modulation elements 11ai and 21ai may be composed of a gel (dry gel). For example, a gel patterned to correspond to the pillar P can be formed on the transparent substrate C10 shown in FIG. 3.

[0085] Furthermore, the plurality of optical modulation elements 11a1 to 11a4 may be integrated. The plurality of optical modulation elements 11a1 to 11a4 can be integrally formed in the dry gel. By doing so, it becomes easy to create the plurality of optical modulation elements 11a1 to 11a4. Similarly, the plurality of optical modulation elements 21a1 to 21a4 may be integrally formed in the dry gel.

[0086] The dry gel 11 is translucent to the signal light and is obtained by drying the gel. A gel is a general term for a solid in which a network is formed by the connection of the dispersed phase. The gel can absorb a solvent in the network and can become a swollen gel. Also, the gel shrinks while releasing the solvent by drying the contained solvent, and becomes a dry gel. Here, a polymer gel is used as the gel that becomes the dry gel 11 by drying the solvent. In particular, it is preferable to use a gel that shrinks while maintaining a similar shape by performing dehydration shrinkage, for example, a gel used in the Implosion Fabrication method.

[0087] 〔Supplementary Notes〕 The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims. Embodiments obtained by appropriately combining the respective technical means disclosed in the above-described embodiments are also included in the technical scope of the present invention.

[0088] 〔Summary〕 The optical computing device according to Aspect 1 of the present invention includes an optical modulation element group including at least one optical modulation element. The optical modulation element group is configured to perform a predetermined first optical computation on a first signal light traveling along a specific optical path, and to perform a predetermined second optical computation on a second signal light traveling in a direction opposite to the first signal light along the specific optical path.

[0089] According to the above configuration, it becomes possible to execute bidirectional optical operations. That is, meaningful optical operations can be executed both when signal light is input to the optical modulation element group from a specific direction and when signal light is input to the optical modulation element group from a direction opposite to the specific direction.

[0090] In the optical operation device according to Embodiment 2 of the present invention, in addition to the configuration of Embodiment 1, the optical modulation element has a configuration in which it has a plurality of cells in which the thickness or refractive index is independently set, or the refractive index can be independently set.

[0091] According to the above configuration, the amount of phase change of the signal light transmitted through each cell can be set independently for each cell, or can be set independently.

[0092] In the optical operation device according to Embodiment 3 of the present invention, in addition to the configuration of Embodiment 2, a configuration is adopted in which a control unit for independently controlling the refractive index of each of the plurality of cells is provided.

[0093] According to the above configuration, the control unit can control the amount of phase change of the signal light transmitted through each cell.

[0094] In the optical operation device according to Embodiment 4 of the present invention, in addition to the configuration of Embodiment 1 or 2, a configuration is adopted in which the at least one optical modulation element is formed in a gel.

[0095] According to the above configuration, the stability of the optical operation by the at least one optical modulation element is improved.

[0096] In the optical operation device according to Embodiment 5 of the present invention, in addition to the configuration of any one of Embodiments 1 to 4, a configuration is adopted in which the optical modulation element group is composed of two or more optical modulation elements arranged along the specific optical path.

[0097] According to the above configuration, it becomes possible to execute bidirectional multi-stage optical operations.

[0098] In the optical computing device according to Aspect 6 of the present invention, in addition to the configuration of Aspect 5, a configuration is adopted in which the first optical operation and the second optical operation are different optical operations.

[0099] According to the above configuration, different optical operations can be executed when signal light is input to the optical modulation element group from a specific direction and when signal light is input to the optical modulation element group from a direction opposite to the specific direction.

[0100] In the optical computing device according to Aspect 7 of the present invention, in addition to the configuration of Aspect 5, a configuration is adopted in which the first optical operation and the second optical operation are the same optical operation.

[0101] According to the above configuration, the same optical operation can be executed when signal light is input to the optical modulation element group from a specific direction and when signal light is input to the optical modulation element group from a direction opposite to the specific direction.

[0102] In the optical computing device according to Aspect 8 of the present invention, in addition to the configuration of any one of Aspects 1 to 7, the optical modulation element group is composed of at least one transmissive optical modulation element, and the specific optical path is a linear optical path passing through each optical modulation element belonging to the optical modulation element group. A configuration is adopted.

[0103] According to the above configuration, it becomes possible to execute bidirectional optical operations using transmissive optical modulation elements.

[0104] In the optical computing device according to Aspect 9 of the present invention, in addition to the configuration of any one of Aspects 1 to 7, the optical modulation element group is composed of at least one reflective optical modulation element, and the specific optical path is a polygonal optical path passing through each optical modulation element belonging to the optical modulation element group. A configuration is adopted.

[0105] According to the above configuration, it becomes possible to execute bidirectional optical operations using reflective optical modulation elements.

[0106] In the optical computing device according to Aspect 10 of the present invention, in addition to the configuration of any one of Aspects 1 to 9, a configuration is adopted in which the first signal light and the second signal light are signal lights having different wavelengths from each other.

[0107] According to the above configuration, it becomes easy to match the forward optical computation with the first optical computation and to match the reverse optical computation with the second optical computation.

[0108] In the optical computing device according to Aspect 11 of the present invention, in addition to the configuration of any one of Aspects 1 to 10, a configuration is adopted in which the first signal light and the second signal light are signal lights having different polarization directions from each other.

[0109] According to the above configuration, it becomes easy to match the forward optical computation with the first optical computation and to match the reverse optical computation with the second optical computation.

[0110] In the optical computing device according to Aspect 12 of the present invention, in addition to the configuration of any one of Aspects 1 to 11, a configuration is adopted in which the first signal light and the second signal light are signal lights having different coherence lengths from each other.

[0111] According to the above configuration, it becomes easy to match the forward optical computation with the first optical computation and to match the reverse optical computation with the second optical computation.

[0112] In the optical computing device according to Aspect 13 of the present invention, in addition to the configuration of any one of Aspects 1 to 12, a combination of a first light emitting device that generates the first signal light before the first optical computation and a second light emitting device that generates the second signal light before the second optical computation, and one or both of a combination of a first light receiving device that detects the first signal light after the first optical computation and a second light receiving device that detects the second signal light after the second optical computation are further provided.

[0113] According to the above configuration, it is possible to achieve bidirectional optical computing without using an external light-emitting device, and / or it is possible to achieve bidirectional optical computing without using an external light-receiving device.

[0114] In the optical computing device according to Aspect 14 of the present invention, in addition to the configuration of any one of Aspects 1 to 13, among the first signal light before the first optical computing and the second signal light after the second optical computing, a first optical element that reflects one and transmits the other, and among the second signal light before the second optical computing and the first signal light after the first optical computing, one or both of a second optical element that reflects one and transmits the other are further provided.

[0115] According to the above configuration, it is possible to arrange the first light-emitting device that generates the first signal light and the second light-receiving device that detects the second signal light at different locations, and / or it is possible to arrange the second light-emitting device that generates the second signal light and the first light-receiving device that detects the first signal light at different locations.

[0116] The optical computing method according to Aspect 15 of the present invention uses an optical modulation element group composed of at least one optical modulation element, and the optical modulation element group performs a predetermined first optical computing on the first signal light traveling along a specific optical path, and the optical modulation element group performs a predetermined second optical computing on the second signal light traveling in the opposite direction to the first signal light along the specific optical path.

[0117] According to the above configuration, it is possible to execute bidirectional optical computing.

[0118] The manufacturing method of the optical computing device according to Aspect 16 of the present invention is a manufacturing method of an optical computing device including an optical modulation element group composed of at least one optical modulation element, and the optical modulation element group performs a predetermined first optical computing on the first signal light traveling along a specific optical path and performs a predetermined second optical computing on the second signal light traveling in the opposite direction to the first signal light along the specific optical path, and includes a step of creating the optical modulation element group.

[0119] According to the above configuration, it becomes possible to manufacture an optical arithmetic unit that executes bidirectional optical arithmetic operations.

Explanation of symbols

[0120] 1, 2 Optical arithmetic unit 11, 21 Optical modulator element groups 11ai, 21ai Optical modulator elements 121, 221 First light emitting device 122, 222 Second light emitting device 131, 231 First light receiving device 132, 232 Second light receiving device 141, 241 First optical element 142, 242 Second optical element

Claims

1. Comprising a group of optical modulation elements including at least one optical modulation element, the group of optical modulation elements is configured to perform a predetermined first optical operation on a first signal light traveling along a specific optical path, and perform a predetermined second optical operation on a second signal light traveling in a direction opposite to that of the first signal light along the specific optical path, each optical modulation element included in the group of optical modulation elements has a plurality of cells whose thickness or refractive index is independently set, or whose refractive index can be independently set, and by interfering signal lights with different phases diffracted in each cell with each other, a predetermined optical operation is performed without using a polarizer, characterized in that it is an optical computing device.

2. The group of optical modulation elements includes two or more optical modulation elements arranged along the specific optical path, characterized in that it is the optical computing device according to claim 1.

3. The first optical operation and the second optical operation are different optical operations, characterized in that it is the optical computing device according to claim 2.

4. The first optical operation and the second optical operation are the same optical operation, characterized in that it is the optical computing device according to claim 2.

5. Comprising a control unit for independently controlling the refractive index of each of the plurality of cells, characterized in that it is the optical computing device according to any one of claims 1 to 4.

6. The at least one optical modulation element is formed in a gel, characterized in that it is the optical computing device according to any one of claims 1 to 4.

7. The group of optical modulation elements includes at least one transmissive optical modulation element, the specific optical path is a linear optical path passing through each optical modulation element belonging to the group of optical modulation elements, characterized in that it is the optical computing device according to any one of claims 1 to 4.

8. The group of optical modulation elements includes at least one reflective optical modulation element, the specific optical path is a polygonal optical path passing through each optical modulation element belonging to the group of optical modulation elements, characterized in that it is the optical computing device according to any one of claims 1 to 4.

9. The first signal light and the second signal light are signal lights with different wavelengths from each other, characterized in that it is the optical computing device according to any one of claims 1 to 4.

10. The first signal light and the second signal light are signal lights with different polarization directions from each other, characterized in that it is the optical computing device according to any one of claims 1 to 4.

11. The first signal light and the second signal light are signal lights with different coherence lengths from each other, The optical computing device according to any one of claims 1 to 4, characterized in that...

12. A combination of a first light emitting device that generates the first signal light before the first optical computation and a second light emitting device that generates the second signal light before the second optical computation, and One or both of a combination of a first light receiving device that detects the first signal light after the first optical computation and a second light receiving device that detects the second signal light after the second optical computation are further provided, The optical computing device according to any one of claims 1 to 4, characterized in that...

13. A first optical element that reflects one of the first signal light before the first optical computation and the second signal light after the second optical computation and transmits the other, and One or both of a second optical element that reflects one of the second signal light before the second optical computation and the first signal light after the first optical computation and transmits the other are further provided, The optical computing device according to any one of claims 1 to 4, characterized in that...

14. Using an optical modulation element group including at least one optical modulation element, The optical modulation element group includes a step of performing a predetermined first optical computation on a first signal light traveling along a specific optical path, and a step of performing a predetermined second optical computation on a second signal light traveling in a direction opposite to the first signal light along the specific optical path, Each optical modulation element included in the optical modulation element group has a plurality of cells in which the thickness or refractive index is independently set, or the refractive index can be independently set, and by interfering signal lights with different phases diffracted in each cell with each other, a predetermined optical computation is performed without using a polarizer. The optical computing method characterized by that...

15. In a method for manufacturing an optical computing device including an optical modulation element group including at least one optical modulation element, The optical modulation element group includes a step of creating the optical modulation element group so as to perform a predetermined first optical computation on a first signal light traveling along a specific optical path and a predetermined second optical computation on a second signal light traveling in a direction opposite to the first signal light along the specific optical path, Each optical modulation element included in the optical modulation element group has a plurality of cells in which the thickness or refractive index is independently set, or the refractive index can be independently set, and by interfering signal lights with different phases diffracted in each cell with each other, a predetermined optical computation is performed without using a polarizer. The method for manufacturing an optical computing device characterized by that...

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