Optical computing device

Abstract

In order to realize an optical operation device that processes an optical signal whose intensity distribution changes with time, the optical operation device (1) includes: one or more optical diffraction elements (10a to 10e) each having a plurality of microcells; and an optical signal input unit (20) that simultaneously inputs an optical signal (S1) and an optical signal obtained by delaying the optical signal, i.e., a delayed optical signal (optical signal S2), to the plurality of optical diffraction elements.

Description

Technical Field

[0001] The present invention relates to an optical computing device that performs predetermined operations in an optical manner. Background Technology

[0002] A known optical diffraction element has an optical diffraction structure formed on a main surface of a substrate. This optical diffraction structure has multiple micro-units with independently set thicknesses or refractive indices, and performs predetermined operations optically by interfering with the light transmitted through each micro-unit. Here, "micro-unit" refers, for example, to a unit with a unit size less than 10 μm. Furthermore, "unit size" refers to the square root of the unit's area.

[0003] In such an optical diffraction element, the intensity distribution of light illuminating an effective region comprising multiple micro-units represents the optical signal. The optical diffraction element converts the intensity distribution of the optical signal into different intensity distributions by interfering with the light passing through each micro-unit, as described above. Thus, a predetermined optical operation (optical calculation) is performed in the optical diffraction element in the form of this intensity distribution conversion.

[0004] Optical computing devices using multiple optical diffraction elements have the advantages of high speed and low power consumption compared to electrical computing devices using processors. Patent Document 1 discloses an optical neural network having an input layer, an intermediate layer, and an output layer. The aforementioned optical diffraction elements can, for example, be used as the intermediate layer of such an optical neural network.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: US Patent No. 7,847,225 Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] However, as in Patent Document 1 Figure 1 As shown, existing optical computing devices are configured to use images (i.e., still images) whose intensity distribution does not change over time as optical signals.

[0010] A still image is an image that captures the state of a subject at a single moment. Therefore, a single still image does not contain information about changes that the subject undergoes over time (e.g., changes in position, changes in state, etc.). Consequently, existing optical processing devices cannot process the changes in the information represented by optical signals over time.

[0011] The present invention addresses the above-mentioned problems by providing an optical processing device that processes optical signals whose intensity distribution changes over time.

[0012] (II) Technical Solution

[0013] To solve the above problems, an optical computing device according to an aspect of the present application includes one or more optical diffraction elements each having a plurality of microcells whose thicknesses or refractive indexes are independently set, and an optical signal input unit configured to simultaneously input, at least at one time, an optical signal and a delayed optical signal obtained by delaying the optical signal to the one or more optical diffraction elements.

[0014] To solve the above problems, an optical computing method according to an aspect of the present application includes a delaying step of generating a delayed optical signal by delaying a part of an optical signal, and an input procedure of simultaneously inputting, at least at one time, the optical signal and the delayed optical signal to one or more optical diffraction elements each having a plurality of microcells whose thicknesses or refractive indexes are independently set.

[0015] (III) Advantages

[0016] According to an aspect of the present application, an optical computing device that processes an optical signal whose intensity distribution changes over time can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 (a) of FIG. 1 is a schematic view of an optical computing device according to a first embodiment of the present application. Figure 1 (b) of FIG. 1 is a flowchart of an optical computing method implemented in the optical computing device shown in (a) of FIG. 1. Figure 1

[0018] Figure 2 is a perspective view of an optical diffraction element included in the optical computing device shown in (a) of FIG. 1. Figure 1

[0019] Figure 3 is a schematic view of a modification example of the optical computing device shown in (a) of FIG. 1. Figure 1

[0020] Figure 4 is a schematic view of a modification example of the optical computing device shown in (a) of FIG. 1. Figure 1

[0021] Figure 5 is a perspective view of an optical computing device according to a second embodiment of the present application. DETAILED DESCRIPTION

[0022] (First Embodiment)

[0023] Reference will now be made in detail to the optical computing device 1 according to the first embodiment of the present application with reference to FIG. 1. Figure 1 and Figure 2 Reference will now be made in detail to the optical computing device 1 according to the first embodiment of the present application with reference to FIG. 1. Figure 1 (a) of FIG. 1 is a schematic view of the optical computing device 1. In​​​​Figure 1 In (a), an orthogonal coordinate system is established such that the surface of the base on which each component of the optical signal input unit 20 is disposed is parallel to the zx plane, and the y-axis direction is parallel to the vertical direction. Furthermore, the direction of transmitting the optical signal S is set as the positive z-axis, the vertical downward direction is set as the positive y-axis, and the positive x-axis direction is determined in such a way that it, together with the positive y-axis and the positive z-axis, forms a right-handed orthogonal coordinate system. Figure 1 (b) is a flowchart of the optical computing method M10 implemented in the optical computing device 1. The optical computing method M10 is also an embodiment of the present invention. Figure 2 This is a three-dimensional view of the optical diffraction element 11a of the optical computing device 1.

[0024] like Figure 1 As shown, the optical processing device 1 has five optical diffraction elements 10a, 10b, 10c, 10d, and 10e, an optical signal input unit 20, and a lens group 30.

[0025] <Lens Group>

[0026] Lens group 30 includes multiple lenses ( Figure 1 (Not shown in the image). Each lens is arranged along the optical axis with its respective light-transmitting area, i.e., its effective area, overlapping. Lens group 30 is preferably configured to allow for focal length adjustment within a specified range.

[0027] The lens group 30 is fixed relative to the optical signal input section 20 in such a way that its relative position with respect to the optical signal input section 20 does not move.

[0028] The lens group 30 adjusts the direction of travel of the light beam incident on the initial lens and images the beam on the incident surface of the optical diffraction element 10a, which will be described later. The light beam input to the light signal input unit 20 from the final stage of the lens group 30 has a time-varying intensity distribution on the illumination surface of the lens group 30. Hereinafter, the light beam input to the light signal input unit 20 will be referred to as the light signal S. Thus, when the intensity distribution of the light signal S is observed at a predetermined position (e.g., the exit surface of the lens group 30), this intensity distribution changes with time.

[0029] The lens group 30 preferably includes a bandpass filter that allows light of a predetermined wavelength to pass through after the plurality of lenses. In this embodiment, the center wavelength of the passband of this bandpass filter is 800 nm, and the width of the passband is 10 nm. Furthermore, the center wavelength and width of the passband of the bandpass filter can be appropriately determined according to the application of the optical processing device 1, etc. For example, the center frequency of the bandpass filter can be appropriately determined in a band of 360 nm to 1000 μm. This band consists of a visible light band (360 nm to 830 nm), a near-infrared band (830 nm to 2 μm), a mid-infrared band (2 μm to 4 μm), and a far-infrared band (4 μm to 1000 μm).

[0030] Alternatively, the bandpass filter can be installed inside the optical signal input section 20 instead of the lens group 30.

[0031] <Optical Signal Input Section>

[0032] The optical signal input unit 20 is configured to simultaneously input the intensity distribution of the optical signal S, whose intensity distribution changes with time, at different times to the optical diffraction elements 10a and 10b. In other words, the optical signal input unit 20 is configured to simultaneously input a reference optical signal (in this embodiment, the optical signal S1 output from optical path OP1) and an optical signal obtained by delaying this optical signal (in this embodiment, the optical signal S2 output from optical path OP2) to the optical diffraction elements 10a and 10b. Figure 2 As shown, the optical signal input unit 20 includes: a semi-reflector 21, a delay variable unit 22, a reflector 23, and a base. Additionally, as... Figure 1 As shown in (b), the optical processing method M10 includes a delay step S11 and an input step S12. In the delay step S11, an optical signal S2 obtained by branching a portion of the optical signal S1 is delayed, thereby generating an optical signal S2 as a delayed optical signal. The delay step S11 is implemented in the delay amount variable section 22, which will be described later. In the input step S12, the optical signals S1 and S2 are always simultaneously input to the optical diffraction elements 10a and 10b. The input step S12 is implemented using the semi-reflecting mirror 21 and the reflecting mirror 23, which will be described later.

[0033] Figure 1 The base frame, not shown, is a plate-shaped component, which includes: an optical signal input unit 20, a semi-reflector 21, a delay variable unit 22, and a reflector 23. The main surface of the base frame is parallel to the zx plane.

[0034] The light signal S emitted from the lens group 30 propagates parallel to the positive z-axis inside the light signal input section 20. Figure 1In the present embodiment, the path of the chief ray in the optical signal S is set as an optical path OPI.

[0035] The half mirror 21 is provided on the optical path OPI. The half mirror 21 reflects half of the light and transmits the remaining half of the light when the light is incident at an angle of 45° with respect to the normal direction of the mirror surface. The half mirror 21 is fixed to the main surface of the chassis in such a manner that the mirror surface thereof is parallel to the y-axis direction and the normal of the mirror surface forms an angle of 45° with the optical path OPI. Therefore, the optical signal S is incident at an angle of 45° with respect to the mirror surface of the half mirror 21.

[0036] (First optical path)

[0037] Half of the optical signal S, i.e., the optical signal S1, does not undergo regular reflection on the mirror surface and still propagates in parallel to the positive direction of the z-axis and is input to the optical diffraction element 10a. The path of the chief ray in the optical signal S1 is set as an optical path OP1. The optical path OP1 is an example of the first optical path.

[0038] (Second optical path)

[0039] The remaining half of the optical signal S, i.e., the optical signal S2, undergoes regular reflection on the mirror surface and propagates in the positive direction of the x-axis orthogonal to the direction of the optical path OPI. The path of the chief ray in the optical signal S2 is set as an optical path OP2. The optical path OP2 is an example of the second optical path.

[0040] The delay-amount variable section 22 and the mirror 23 are provided in this order on the optical path OP2.

[0041] The delay-amount variable section 22 includes an optical stage capable of moving the stage 221 in one axial direction and two mirrors 222 and 223.

[0042] The optical stage is fixed to the main surface of the chassis in such a manner that the stage 221 can move in parallel to the x-axis direction. In the present embodiment, the direction in which the stage 221 can move is indicated by an arrow A. Figure 1

[0043] The mirrors 222 and 223 are provided in this order on the main surface of the stage 221. The mirrors 222 and 223 regularly reflect light incident on the mirror surfaces.

[0044] ​The mirror 222 is fixed to the main surface of the stage 221 in such a manner that the mirror surface thereof is parallel to the y-axis direction and the normal line of the mirror surface forms an angle of 45° with the optical path OP2. Therefore, the optical signal S2, which is incident at an angle of 45° with respect to the mirror surface of the half mirror 21, is normally reflected on the mirror surface toward the negative direction of the z-axis. In addition, the mirror 223 is fixed to the main surface of the stage 221 in such a manner that the mirror surface thereof is parallel to the y-axis direction and the normal line of the mirror surface forms an angle of 45° with the optical path OP2. Therefore, the optical signal S2, which is normally reflected by the mirror 222, is incident at an angle of 45° with respect to the mirror surface of the mirror 223 and is normally reflected on the mirror surface toward the negative direction of the x-axis.

[0045] The mirror 23 is fixed to the main surface of the chassis in such a manner that the mirror surface thereof is parallel to the y-axis direction and the normal line of the mirror surface forms an angle of 45° with the optical path OP2. Therefore, the optical signal S2, which is normally reflected by the mirror 223, is incident at an angle of 45° with respect to the mirror surface of the mirror 23 and is normally reflected on the mirror surface toward the positive direction of the z-axis.

[0046] The optical signal S2, which is normally reflected by the mirror 23, propagates in parallel with the positive direction of the z-axis and is input to the optical diffraction element 10b.

[0047] (Difference in optical path length)

[0048] As described above, the half mirror 21 branches the optical path OPI of the transmission optical signal S into the optical path OP1 and the optical path OP2. The length of the optical path OP2 in the actual space, i.e., the actual space length, is longer than the actual space length of the optical path OP1 by an amount corresponding to the difference ΔL. Here, as shown in the drawing, the difference ΔL is found by ΔL = LI + 2L2 + 2L3. Figure 1

[0049] The optical path length of the optical path can be found by the product of the difference ΔL in the actual space and the refractive index of the medium filling the optical path. In the present embodiment, both the optical path OP1 and the optical path OP2 are filled with air. Therefore, the refractive index of the medium filling the optical path can be regarded as substantially 1, and thus the difference in the optical path lengths of the optical path OP1 and the optical path OP2 is substantially equal to the difference ΔL.

[0050] Thus, in the optical signal input section 20, the optical path length of the optical path OP2 is longer than the optical path length of the optical path OP1. Therefore, the optical signal input section 20 can simultaneously input the optical signals S1, S2, which have intensity distributions at different times, of the optical signal S to the optical diffraction elements 10a, 10b. The optical signal S1 is an optical signal that serves as a reference with respect to the optical signal S2 described later, and the optical signal S2 is a delayed optical signal obtained by delaying the optical signal S1.

[0051] (Delay amount variable section) ​

[0052] As described above, the delay variable unit 22 can move the position of stage 221 along the x-axis. When stage 221 is moved towards the negative x-axis (approaching the half-reflector 21 and the reflector 23), the difference ΔL decreases. On the other hand, when stage 221 is moved towards the positive x-axis (moving away from the half-reflector 21 and the reflector 23), the difference ΔL increases. Therefore, the delay variable unit 22 can adjust the position of stage 221 to change the time difference, i.e., the delay, between the optical signals S1 and S2 input to the optical diffraction elements 10a and 10b.

[0053] Additionally, a high-refractive-index component can be provided on the optical path OP2. This high-refractive-index component is made of a material with a refractive index higher than that of air. As an example of a high-refractive-index component, a plate-shaped component 24 made of transparent resin can be provided, which is disposed between the semi-reflective mirror 21 and the variable retardation portion 22, and between the variable retardation portion 22 and the reflector 23. Figure 1 The plate-shaped component 24 is represented by an imaginary line (double-dotted line). Furthermore, the plate-shaped component 24 can be disposed either between the semi-reflecting mirror 21 and the variable retardation portion 22, or between the variable retardation portion 22 and the reflecting mirror 23. Additionally, the plate-shaped component 24 can also be disposed between the reflecting mirrors 222 and 223. Furthermore, the shape of the high-refractive-index component is not limited to a plate-shaped component; it can be appropriately determined, for example, it can also be block-shaped.

[0054] The thicker the plate-shaped component 24 (its length along the x-axis), or the greater the refractive index of the resin constituting the plate-shaped component 24, the greater the difference in optical path length between optical path OP1 and optical path OP2 can be widened. Therefore, the plate-shaped component 24 also functions as a variable delay part, which causes the time difference, i.e., the delay, of the optical signals S1 and S2 input to the optical diffraction elements 10a and 10b to change.

[0055] (The moment when each optical signal is input to the optical diffraction element)

[0056] In such Figure 1 In the optical processing device 1 configured as shown in (a), the optical signal input unit 20 is configured to simultaneously input optical signals S1 and S2 to the optical diffraction elements 10a and 10b at all times. However, in one embodiment of the present invention, the optical signal input unit 20 may also be configured to simultaneously input optical signals S1 and S2 to the optical diffraction elements 10a and 10b at least at one moment. In other words, the optical signal input unit 20 may also be configured to input either optical signal S1 or optical signal S2 to the optical diffraction element 10a or optical diffraction element 10b in any direction for at least one moment, for both optical signals S1 and S2.

[0057] In addition, as a mechanism for inputting or blocking each optical signal S1, S2 to each optical diffraction element 10a, 10b at any time, a light blocker provided on the optical path of each optical path OP1, OP2 can be used.

[0058] Alternatively, it can be configured such that optical signals S1 and S2 are simultaneously input to optical diffraction elements 10a and 10b at least at one moment. This is important for... Figure 1 The same applies to the optical operation method M10 shown in (b).

[0059] <Optical Diffraction Elements>

[0060] like Figure 2 As shown, optical diffraction elements 10a, 10b, 10c, 10d, and 10e are provided after the optical signal input section 20. The structure of the optical diffraction element will be described below using optical diffraction element 10a as an example. Optical diffraction elements 10b, 10c, and 10d are configured the same as optical diffraction element 10a. Furthermore, although optical diffraction element 10e is configured similarly to optical diffraction element 10a, the shape and size of its central portion 113 are different. In optical diffraction element 10a, the central portion 113 is the length L of one side (refer to...). Figure 2 The first part is a square with a length of 200 μm. On the other hand, in the optical diffraction element 10e, the central part 113 is a rectangle with a short side length of 200 μm and a long side length of 400 μm.

[0061] (structure)

[0062] like Figure 2 As shown, the optical diffraction element 10a has a substrate 11 and an optical diffraction structure 12.

[0063] The substrate 11 is a layered component (e.g., a thin film) having opposing main surfaces 111 and 112, and is made of a light-transmitting material. Main surface 111 is an example of one of the main surfaces of the substrate 11. Furthermore, the portion of the substrate 11 located at the center of the main surface 111 will be referred to as the central portion 113, and the annular portion surrounding the central portion 113 will be referred to as the annular portion 114. Additionally, in Figure 2 The underlined dotted line added to the reference numeral "113" in the figure indicates that the central part 113 is located in the lower layer of the light diffraction structure 12.

[0064] In this embodiment, an acrylic resin is used as the material constituting the substrate 11. However, the material constituting the substrate 11 is not limited to resins such as acrylic resins, as long as it is transparent in the wavelength range of the light used as signal light. The material constituting the substrate 11 can also be a glass material such as quartz glass.

[0065] In addition, the material constituting the substrate 11 is preferably a material that has good adhesion with a resin (e.g., a photocurable resin) constituting the light diffraction structure 12 when the light diffraction structure 12 is formed on the main surface 111.

[0066] In addition, in the present embodiment, 5 μm is adopted as the thickness of the substrate 11. A resin film of such a thickness cannot be supported independently as a single body because it is flexible. In addition, the thickness of the substrate 11 is not limited to 5 μm.

[0067] In addition, the shape of the substrate 11 (hereinafter referred to as the plan view shape) as viewed from the normal direction of the main surface 111 is a square. In addition, the substrate 11 can have a size and a shape that are appropriately determined as long as the size exceeds that of the central portion 113 described later.

[0068] The light diffraction structure 12 is formed on the central portion 113. In the present embodiment, the central portion 113 is, for example, a square having a length L of one side of 200 μm. The light diffraction structure 12 is constituted by a plurality of microcells A in which the thickness or the refractive index is independently set (see FIG. 2). Figure 1 In the present embodiment, each microcell A is made of a resin (e.g., a photocurable resin) having light transmittance. However, the light diffraction structure 12 can be made of glass (e.g., quartz glass).

[0069] When signal light is incident on the light diffraction structure 12, the signal light that has passed through each microcell A interferes with each other, thereby performing a predetermined optical operation. The intensity distribution of the signal light output from the light diffraction structure 12 represents the result of the optical operation.

[0070] Here, the "microcell" refers to, for example, a cell having a cell size of less than 10 μm. In addition, the "cell size" refers to the square root of the area of the cell. For example, when the plan view shape of the microcell is a square, the cell size is the length of one side of the cell. The lower limit of the cell size is not particularly limited and is, for example, 1 nm.

[0071] Figure 3 The light diffraction structure 12 exemplified in the enlarged view of FIG. 1 is constituted by 20 x 20 microcells A arranged in a matrix. The plan view shape of each microcell A is, for example, a square of 1 μm x 1 μm, and the plan view shape of the light diffraction structure 12 is, for example, a square of 200 μm x 200 μm.

[0072] In addition, the cell size, the plan view shape of each microcell A, and the plan view shape of the light diffraction structure 12 are not limited to the above-described examples and can be appropriately determined.

[0073] (Optical operation on optical signal)

[0074] The light-diffraction element 10a is configured to input the optical signal S1 propagating in the optical path OP1 to the incident plane. The light-diffraction element 10a performs a prescribed optical operation on the optical signal S1.

[0075] The light-diffraction element 10b is configured to input the optical signal S2 propagating in the optical path OP2 to the incident plane. The light-diffraction element 10b performs a prescribed optical operation on the optical signal S2.

[0076] The light-diffraction element 10c is configured in a manner that the effective regions overlap each other at a stage subsequent to the light-diffraction element 10a. The light-diffraction element 10c performs a prescribed optical operation on the optical signal S1 on which the optical operation has been performed by the light-diffraction element 10a.

[0077] The light-diffraction element 10d is configured in a manner that the effective regions overlap each other at a stage subsequent to the light-diffraction element 10b. The light-diffraction element 10d performs a prescribed optical operation on the optical signal S2 on which the optical operation has been performed by the light-diffraction element 10b.

[0078] In addition, the light-diffraction element 10a and the light-diffraction element 10b are independent light-diffraction elements from each other. In addition, the light-diffraction element 10c and the light-diffraction element 10d are independent light-diffraction elements from each other. A light-shielding plate 14 that does not transmit light is provided between the light-diffraction element 10a and the light-diffraction element 10b, and between the light-diffraction element 10c and the light-diffraction element 10d.

[0079] Therefore, the light-diffraction element 10a and the light-diffraction element 10c cause only the optical signal S1 that has transmitted through each microcell to interfere, and do not cause the optical signal S2 to interfere. In other words, the light-diffraction element 10a and the light-diffraction element 10c perform an optical operation on only the optical signal S1, and do not affect the optical signal S2. Similarly, the light-diffraction element 10b and the light-diffraction element 10d cause only the optical signal S2 that has transmitted through each microcell to interfere, and do not cause the optical signal S1 to interfere. In other words, the light-diffraction element 10b and the light-diffraction element 10d perform an optical operation on only the optical signal S2, and do not affect the optical signal S1.

[0080] The light-diffraction element 10e is configured at a stage subsequent to the light-diffraction element 10c and the light-diffraction element 10d. The effective region of the light-diffraction element 10e overlaps the effective region of the light-diffraction element 10c and the effective region of the light-diffraction element 10d.

[0081] The light-diffraction element 10e is different from the light-diffraction elements 10a to 10d, and causes the optical signal S1 and the optical signal S2 that have transmitted through each microcell to interfere with each other. In other words, the light-diffraction element 10e affects the optical signal S1 and the optical signal S2.

[0082] Also, in the present embodiment, a light diffraction element of three stages is employed. However, the number of stages of the light diffraction element is not limited to three, and can be appropriately determined. Also, in the present embodiment, the light diffraction element of the first stage and the light diffraction element of the second stage are respectively provided independently with respect to the optical path OP1 and the optical path OP2. However, the light diffraction element of the first stage and the light diffraction element of the second stage can be provided to be shared with respect to the optical path OP1 and the optical path OP2 as with the light diffraction element 10e of the third stage. Also, in the present embodiment, the light diffraction element of the third stage is provided to be shared with respect to the optical path OP1 and the optical path OP2. However, the light diffraction element of the third stage can be provided to be independent with respect to the optical path OP1 and the optical path OP2.

[0083] <Modification example>

[0084] Reference Figure 4 and Figure 1 To Figure 3 A modification example of the optical computing device 1, that is, an optical computing device 1A, will be described. Figure 4 and Figure 1 are schematic diagrams of the optical computing device 1A. As with the case of Figure 3 , the Figure 4 is a schematic diagram when the chassis of the light signal input portion is viewed from above, Figure 3 is a schematic diagram when the light diffraction element of the first stage is viewed from above from the input direction of the light signal.

[0085] As shown in Figure 3 , the optical computing device 1A is provided with three light diffraction elements 101, 102, 103 and a light signal input portion 40. Also, in Figure 2 , the optical computing device 1A is provided with the same lens group as the lens group 30 of the optical computing device 1.

[0086] The light diffraction element 101 of the optical computing device 1A corresponds to the light diffraction elements 10a, 10b of the optical computing device 1, the light diffraction element 102 of the optical computing device 1A corresponds to the light diffraction elements 10c, 10d of the optical computing device 1, and the light diffraction element 103 of the optical computing device 1A corresponds to the light diffraction element 10e of the optical computing device 1.

[0087] In each of the light diffraction elements 101 to 103, the central portion 113 of the microcell A (refer to Figure 3 ) is a square with a side length L of 400 μm. Each of the light diffraction elements 101 to 103 causes the light signals S1 to S4 that have passed through each of the microcells A to interfere with each other. In other words, each of the light diffraction elements 101 to 103 affects each of the light signals S1 to S4.

[0088] (Light signal input portion)

[0089] The optical signal input section 40 of the optical computing device 1A is obtained by deforming the optical signal input section 20 of the optical computing device 1. The optical computing device 1 is provided with one half mirror 21 and is configured to branch the optical path OPI of the optical signal S into two optical paths, i.e., the optical paths OP1 and OP2. On the other hand, the optical computing device 1A is provided with three half mirrors 41, 42, and 45 and is configured to branch the optical path OPI of the optical signal S into four optical paths, i.e., the optical paths OP1, OP2, OP3, and OP4. The optical signal input section 40 of the present modification example will be described with respect to this point. In addition, in Figure 4 and Figure 1 the arrows are used to indicate the respective positions of the half mirrors 41, 42, and 45 and the mirrors 43, 44, and 46, and the actual shapes of the half mirrors and the mirrors are omitted from the drawings.

[0090] (First optical path)

[0091] As in the case of the optical signal input section 20, the half mirror 41 corresponding to the half mirror 21 is provided in the optical path OPI. When light is incident at an angle of 45° with respect to the normal direction of the mirror surface, the half mirror 41 reflects 75% of the light and transmits the remaining 25% of the light. The optical signal S is incident on the half mirror 41 at an angle of 45° with respect to the mirror surface.

[0092] The 25% of the optical signal S, i.e., the optical signal S1, does not undergo regular reflection on the mirror surface, still propagates in the positive direction of the z axis, and is input to the optical diffraction element 101. The path of the chief ray in the optical signal S1 is set as the optical path OP1. The optical path OP1 is an example of the first optical path.

[0093] (Second optical path)

[0094] The remaining 75% of the optical signal S, i.e., the optical signal S1', undergoes regular reflection on the mirror surface and propagates in the positive direction of the x axis orthogonal to the direction of the optical path OPI.

[0095] The half mirror 42 is provided in the optical path of the optical signal S1' that is regularly reflected by the half mirror 41. When light is incident at an angle of 45° with respect to the normal direction of the mirror surface, the half mirror 42 reflects 33.3% of the light and transmits the remaining 66.6% of the light. The optical signal S1' is incident on the half mirror 42 at an angle of 45° with respect to the mirror surface.

[0096] The 33.3% of the optical signal S1', i.e., the optical signal S2, undergoes regular reflection on the mirror surface, propagates in the positive direction of the z axis, and is input to the optical diffraction element 101. The paths of the chief rays in the optical signal S1' and the optical signal S2 are set as the optical path OP2. The optical path OP2 is an example of the second optical path.

[0097] (Third optical path)

[0098] The remaining 66.6% of the optical signal S1', i.e., the optical signal S2', does not undergo regular reflection at the mirror surface of the half mirror 42 and still propagates in the positive direction of the x axis.

[0099] The mirrors 43, 44, and the half mirror 45 are provided on the optical path of the optical signal S2'. The mirrors 43, 44, and the half mirror 45 are arranged in this order in the positive direction of the z axis. Figure 5 The mirrors 222, 223 are similarly configured as shown. Thus, the optical signal S2' is regularly reflected by the mirrors 222, 223 and propagates in the negative direction of the x axis.

[0100] The half mirror 45 regularly reflects 50% of light and transmits the remaining 50% of light when light is incident at an angle of 45° with respect to the normal direction of the mirror surface. The optical signal S2' is incident at an angle of 45° with respect to the mirror surface of the half mirror 43.

[0101] The 50% of the optical signal S2', i.e., the optical signal S3, undergoes regular reflection at the mirror surface of the half mirror 45 and propagates in the positive direction of the z axis and is input to the light diffraction element 101. The path of the chief ray in the optical signal S2' and the optical signal S3 is set as an optical path OP3. The optical path OP3 is an example of a third optical path.

[0102] (Fourth Optical Path)

[0103] The remaining 50% of the optical signal S2', i.e., the optical signal S4, does not undergo regular reflection at the mirror surface of the half mirror 45 and still propagates in the negative direction of the x axis.

[0104] The mirror 46 is provided on the optical path of the optical signal S4. The optical signal S4 transmitted through the half mirror 45 is regularly reflected in the positive direction of the z axis at an angle of 45° with respect to the mirror surface of the mirror 46.

[0105] The optical signal S4 that has undergone regular reflection by the mirror 46 propagates in parallel with the positive direction of the z axis and is input to the light diffraction element 101. The path of the chief ray in the optical signal S4 is set as an optical path OP4. The optical path OP4 is an example of a fourth optical path.

[0106] (Difference in Length of Optical Paths)

[0107] As described above, the half mirrors 41, 42, and 45 branch the optical path OPI of the transmitted optical signal S into the optical paths OP1 to OP4. The lengths of the optical paths OP1 to OP4 in the actual space, i.e., the actual space lengths, become longer in the order of the optical paths OP1, OP2, OP3, and OP4.

[0108] Thus, in the optical signal input section 40, the optical path lengths of the respective optical paths OP1 to OP4 are different, and therefore the optical signals S1, S2, S3, S4 having intensity distributions at different times of the optical signal S can be simultaneously input to the optical diffraction element 101. The optical signal S1 is a reference optical signal with respect to the optical signals S2, S3, S4 to be described later. In addition, the optical signals S2, S3, S4 are all delayed optical signals obtained by delaying the optical signal S1.

[0109] (Second Embodiment)

[0110] Reference Figure 5 The optical arithmetic device 2 of the second embodiment of the present application will be described. Figure 5 is a perspective view of the optical arithmetic device 2.

[0111] As shown in Figure 3 , the optical arithmetic device 2 is provided with an optical signal input section 50 and optical diffraction elements 101 to 103. The optical diffraction elements 101 to 103 of the optical arithmetic device 2 are configured to be the same as the optical diffraction elements 101 to 103 of the optical arithmetic device 1A (refer to Figure 5 ). Therefore, in the present embodiment, the optical signal input section 50 will be described.

[0112] <Optical Signal Input Section>

[0113] As shown in ​ , the optical signal input section 50 is provided with an imaging section 51, an image processing section 52, a display control section 53, and display sections 54 to 57.

[0114] The imaging section 51 is provided with a lens group composed of a plurality of lenses and an imaging element.

[0115] The lens group adjusts the traveling direction of an optical beam incident on a lens of the initial stage, and images the optical beam on the incident surface of the optical diffraction element 10a to be described later. The optical beam input from the last stage of the lens group to the imaging element has an intensity distribution varying with time on the irradiation surface thereof. Hereinafter, the optical beam input to the imaging element will be referred to as an optical signal S.

[0116] The imaging element converts the optical signal S incident on the light-receiving surface into an electric signal, and supplies the electric signal to the image processing section 52.

[0117] The image processing section 52 generates a dynamic image from the electric signal supplied from the imaging element. The dynamic image contains a plurality of still images represented by respective frames. The still image represented by each frame is an example of an intensity distribution of the optical signal S at a different time. The frame rate of the dynamic image generated by the image processing section 52 is not limited, and can be appropriately determined in accordance with the moving speed of the object, or the like. When the motion of the object is high speed, it is preferable to set the frame rate to be high. As an example of the frame rate, 100,000 fps (frames / second) can be given.

[0118] The display control section 53 causes the images of the four frames that are different from each other among the frames that constitute the single moving image generated by the image processing section 52 to be displayed on the display sections 54 to 57, respectively. At this time, it is preferable that the display control section 53 cause the images of the four frames to be displayed on the display sections 54 to 57, respectively, using light of one wavelength (for example, 800 nm).

[0119] The display control section 53 can appropriately determine the frame interval of the frames displayed by each of the display sections 54 to 57. For example, when the frame rate of the moving image is 100,000 fps, by causing each of the display sections 54 to 57 to display four images per one frame, it is possible to detect the movement of the object of 10 μsec order. Also, for example, when each of the display sections 54 to 57 displays four images per 100 frames, it is possible to detect the movement of the object of 1 msec order. In this way, the display control section 53 can cause the difference in timing, that is, the amount of delay of the optical signal S to change by controlling the frame interval of the frames displayed by each of the display sections 54 to 57. Therefore, the display control section 53 is an example of an amount-of-delay variable section.

[0120] Each of the display sections 54 to 57 is an organic EL (Electro Luminescence) display. However, each of the display sections 54 to 57 can also be a liquid crystal display. Also, the response speed of the organic EL display is higher than that of the liquid crystal display, and thus it is preferable as the display section of the optical arithmetic device 2. In order to perform the optical arithmetic using the light diffraction elements 101 to 103, the images input to the light diffraction elements 101 to 103 are preferably expressed using light of one wavelength. Therefore, each of the display sections 54 to 57 does not need to be able to perform color display, and can be a monochrome display that is able to display one color (for example, 800 nm in wavelength). By configuring each of the display sections 54 to 57 by a monochrome display, it is possible to improve the resolution compared to the case of a color display.

[0121] Each of the display sections 54 to 57 displays the images of the four frames that are different from each other based on the control signal from the display control section 53. Each of the display sections 54 to 57 is disposed in a manner that opposes the light diffraction element 101, and thus it is possible to simultaneously input the images of the four frames that are different from each other to the light diffraction element 101. The images of the four frames that are different from each other in the moving image are an example of the optical signal. If the image of the frame that is the earliest in timing among the four images of different frames (the image displayed on the display section 54 in the present embodiment) is taken as a reference of the optical signal, the images of the frames that are subsequent in timing (the images displayed on the display sections 55 to 57 in the present embodiment) can all be said to be delayed optical signals. In this way, the optical signal input section 50 of the optical arithmetic device 2 can simultaneously input the optical signal that is a reference and the optical signal that is obtained by delaying the optical signal, that is, the delayed optical signal, to the light diffraction element 101.

[0122] Further, an optical system such as a lens can be present between the display sections 54 to 57 and the light diffraction element 101.

[0123] (SUMMARY)

[0124] The light operation device according to the first aspect of the present application includes one or more light diffraction elements each having a plurality of microcells whose thicknesses or refractive indexes are independently set, and a light signal input section that simultaneously inputs, at least at one time, intensity distributions of a light signal at different times to the one or more light diffraction elements. In other words, the light signal input section of the present light operation device simultaneously inputs, at least at one time, a light signal and a delayed light signal obtained by delaying the light signal to the one or more light diffraction elements.

[0125] According to the above structure, the intensity distributions of the light signal at different times are simultaneously input to the one or more light diffraction elements. In other words, according to the above structure, the light signal and the delayed light signal are simultaneously input to the one or more light diffraction elements. Therefore, the present light operation device can process a light signal whose intensity distribution changes with time.

[0126] Further, in the light operation device according to the second aspect of the present application, in addition to the structure of the light operation device according to the first aspect of the present application, the light signal input section branches an optical path that transmits the light signal into a first optical path and a second optical path whose optical path length is longer than that of the first optical path, and inputs the light signal output from the first optical path and the delayed light signal output from the second optical path to the one or more light diffraction elements, respectively. In other words, in the present light diffraction element, in addition to the structure of the light operation device according to the first aspect of the present application, the light signal input section inputs the light signal output from the first optical path and the delayed light signal output from the second optical path to the one or more light diffraction elements, respectively.

[0127] According to the above structure, the optical path length of the second optical path is longer than that of the first optical path, and thus the time of the light signal output from the second optical path is delayed from the time of the light signal output from the first optical path. Therefore, the present light operation device can easily set the light signal output from the first optical path as a reference light signal, and generate a delayed light signal obtained by delaying the light signal. Therefore, the present light operation device can easily simultaneously input, to the one or more light diffraction elements, the light signal having intensity distributions at different times (i.e., the reference light signal and the delayed light signal).

[0128] Further, according to the present optical operation device, it is possible to easily reduce the difference in timing, that is, the delay amount, between the light signal output from the first optical path and the light signal output from the second optical path. Therefore, the present optical operation device can process high-speed information in which the intensity distribution changes in a short time.

[0129] Further, in the optical operation device of the third aspect of the present application, in addition to the configuration of the optical operation device of the second aspect described above, a high refractive index member composed of a material having a refractive index higher than that of air is provided in the optical path of the second optical path.

[0130] According to the above configuration, the light signal transmitted through the second optical path is delayed when it passes through the high refractive index member. Therefore, the present optical operation device can reliably delay the timing of the light signal output from the second optical path from the timing of the light signal output from the first optical path.

[0131] Further, in the optical operation device of the third aspect of the present application, in addition to the configuration of the optical operation device of the second aspect or the third aspect described above, the actual spatial length of the second optical path is longer than that of the first optical path, and the second optical path is filled with a medium having a refractive index lower than air.

[0132] Further, in the optical operation device of the fourth aspect of the present application, in addition to the configuration of the optical operation device of the second aspect or the third aspect described above, the actual spatial length of the second optical path is longer than that of the first optical path, and the second optical path is filled with a medium having a refractive index lower than air.

[0133] According to the above configuration, it is possible to make the optical path length of the second optical path longer than that of the first optical path with a simple configuration. Further, the optical path length of the optical path can be found by the product of the actual spatial length and the refractive index of the optical path.

[0134] Further, in the optical operation device of the fifth aspect of the present application, in addition to the configuration of the optical operation device of any one of the second aspect to the fourth aspect described above, a half mirror is further provided in the optical path in which the light signal is transmitted, and the transmission path of the light signal is branched into the first optical path and the second optical path which are different from each other.

[0135] According to the above configuration, it is possible to easily generate two light signals having the same intensity distribution from one light signal.

[0136] Further, in the optical arithmetic device of the sixth aspect of the present application, in addition to the configuration of the optical arithmetic device of the first aspect described above, the following configuration is adopted: the optical signal input section displays a plurality of images of frames that constitute a single moving image and are different from each other, and inputs each of the images to the one or more optical diffraction elements.

[0137] Each frame image in a moving image is an example of an optical signal. If an image of a frame that is the earliest in time sequence among a plurality of images of different frames is set as a reference optical signal, images of frames that are later in time sequence can all be called delayed optical signals. According to the configuration described above, a plurality of optical signals having intensity distributions at different times can be easily input to the one or more optical diffraction elements at the same time.

[0138] Further, in the optical arithmetic device of the seventh aspect of the present application, in addition to the configuration of any one of the optical arithmetic devices of the first to sixth aspects described above, the following configuration is adopted: the optical signal input section is provided with a delay amount variable section that changes a delay amount, which is a difference in time of each optical signal input to the one or more optical diffraction elements. Further, in other words, it can also be said that the optical signal input section of the present optical arithmetic device is provided with a delay amount variable section that changes a delay amount generated between the optical signal and the delayed optical signal.

[0139] According to the configuration described above, the delay amount of each optical signal input to the one or more optical diffraction elements can be changed, and thus a delay amount corresponding to a speed at which an intensity distribution changes in an optical signal can be adopted.

[0140] Regarding the optical arithmetic method of the eighth aspect of the present application, it includes a process of inputting the intensity distribution of an optical signal, in which an intensity distribution of light changes over time, at different times at least at one time to the one or more optical diffraction elements. Further, in other words, it can also be said that the present optical arithmetic method includes a delay step of generating a delayed optical signal by delaying a part of an optical signal, and an input process of inputting the optical signal and the delayed optical signal at least at one time to one or more optical diffraction elements having a plurality of microcells whose thicknesses or refractive indexes are independently set.

[0141] The present optical arithmetic method configured as described above achieves the same effects as the optical arithmetic device of the first aspect described above.

[0142] (Matters to be noted)

[0143] The present application is not limited to the above-described respective embodiments, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining the technical means respectively disclosed in the different embodiments are also included in the technical scope of the present application.

[0144] Explanation of Reference Signs

[0145] 1, 1A, 2 - optical computing device; 10a ~ 10e, 101 ~ 103 - optical diffraction element; A - microcell; 20 - optical signal input; 21 - half mirror; 22 - variable delay; 24 - plate-shaped member (variable delay); OP1, OP2 - first light path, second light path; 40, 50 - optical signal input; 41, 42, 45 - half mirror; 51 - camera; 52 - image processing unit; 53 - display control unit (variable delay); 54 ~ 57 - display.

Claims

1. An optical computing device, characterized in that, have: One or more optical diffraction elements having multiple micro-units with independently set thickness or refractive index; and The optical signal input unit simultaneously inputs an optical signal and a delayed optical signal (i.e., a time-delayed optical signal) to the one or more optical diffraction elements at least at one moment. The optical signal input unit includes a variable delay unit that generates a delayed optical signal by delaying a portion of the optical signal. The one or more optical diffraction elements are disposed in the stage following the optical signal input section.

2. The optical computing device according to claim 1, characterized in that, The optical signal input unit branches the optical path for transmitting the optical signal into a first optical path and a second optical path with a length longer than the first optical path, and inputs the optical signal output from the first optical path and the delayed optical signal output from the second optical path to the one or more optical diffraction elements respectively.

3. The optical computing device according to claim 2, characterized in that, A high refractive index component is provided in the optical path of the second optical path. This high refractive index component is made of a material with a refractive index higher than that of air.

4. The optical computing device according to claim 2 or 3, characterized in that, The actual spatial length of the second optical path is longer than that of the first optical path, and the second optical path is filled with a medium with a refractive index lower than that of air.

5. The optical computing device according to claim 2 or 3, characterized in that, It also has a semi-reflective mirror, which is placed in the optical path for transmitting the optical signal, so that the transmission path of the optical signal branches into a first optical path and a second optical path that are different from each other.

6. The optical computing device according to claim 1, characterized in that, The optical signal input unit displays multiple images that constitute a single dynamic image and are different from each other, and inputs each image to the one or more optical diffraction elements.

7. The optical computing device according to claim 1 or 2, characterized in that, The optical signal input unit includes a delay variable unit that changes the delay amount generated between the optical signal and the delayed optical signal.

8. A method for optical computation, characterized in that, Include: The delay step generates a delayed optical signal by temporally delaying a portion of the optical signal in a variable delay portion included in the optical signal input section; and The input process involves simultaneously inputting the optical signal and the delayed optical signal to one or more optical diffraction elements, which are located at the downstream stage of the optical signal input section and have independently set thicknesses or refractive indices, at least at one moment.

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