Port for optical neural network and three-dimensional port for three-dimensional optical neural network

Abstract

The present application provides a port for an optical neural network and a three-dimensional port of a three-dimensional optical neural network. The port of the optical neural network provided in the present application includes: an input port and an output port; wherein the input port is used to receive input light and transmit the input light to the computing layer of the optical neural network; the output port is used to receive output light from the computing layer and emit the output light to a detector array for receiving output light; the input port includes an input optical waveguide device and an input lens array, the input lens array is arranged upstream of the optical path of the input light; the input lens array includes at least two input lenses; the output port includes an output optical waveguide device. The port for an optical neural network provided in the present application can realize independent input and output of each optical waveguide in the optical neural network, reduce the loss of input light and output light, and improve the energy efficiency of the entire optical neural network.

Description

Technical Field

[0001] The present application relates to the field of optical chips, and in particular to a port for an optical neural network and a three-dimensional port of a three-dimensional optical neural network. Background Art

[0002] In recent years, with the in-depth development of optical technology and metamaterial research, people have carried out various studies on the use of optical structures to simulate neural networks, that is, optical neural networks. Among them, the planar photonic circuit neural network structure is usually based on the Mach-Zehnder Interferometer (MZI) to achieve this. This optical neural network has inherent compactness, which greatly facilitates the integration of various optically adjustable devices for programmable neural networks; at the same time, the planar optical neural network can also be arranged into a three-dimensional optical neural network through a certain arrangement method, and the three-dimensional optical neural network can perform multiple tasks in parallel.

[0003] However, the input / output ports of the planar optical neural network in the prior art are all arranged on a single layer, and the coupler arranged on the input port usually cannot completely cover the input light. Therefore, when the input light is directly irradiated vertically to the coupler, the coupler cannot receive all the input light, thereby causing the loss of the input light; and in the output port of the optical neural network in the prior art, due to the divergence angle of the output light, crosstalk will occur between different output lights, resulting in the final calculation result being inaccurate; and the three-dimensional optical neural network composed of multiple optical neural networks also has the same problem, and it is difficult to achieve the independent input and output of multiple couplers. Utility Model Content

[0004] One purpose of the present application is to propose a port for an optical neural network and a three-dimensional port of a three-dimensional optical neural network, which can realize independent input and output of the optical neural network and the three-dimensional optical neural network.

[0005] According to one aspect of an embodiment of the present application, a port for an optical neural network is disclosed, the port comprising: an input port and an output port;

[0006] Wherein, the input port is used to receive input light and transmit the input light to the computing layer of the optical neural network;

[0007] The output port is used to receive the output light from the computing layer and transmit the output light to a detector array for receiving the output light;

[0008] The input port comprises a coupling optical waveguide device and a coupling lens array, wherein the coupling lens array is arranged upstream of the optical path of the input light; the coupling lens array comprises at least two coupling lenses;

[0009] The output port includes an out-coupling optical waveguide device.

[0010] In an exemplary embodiment of the present application, the coupling-in optical waveguide device comprises: a first substrate; at least two first couplers; at least two first optical waveguides;

[0011] The first coupler and the first optical waveguide are arranged on the first substrate, and the first coupler and the first optical waveguide are matched one by one;

[0012] The first coupler is used to receive input light, and the first optical waveguide is used to couple the input light to the computing layer.

[0013] In an exemplary embodiment of the present application, the first coupler is disposed at one end of the first optical waveguide for receiving the input light.

[0014] In an exemplary embodiment of the present application, the coupling-in lens and the first coupler are matched one-to-one;

[0015] The coupling lens is used to focus the input light onto the first coupler.

[0016] In an exemplary embodiment of the present application, the coupling-in lens is a microlens or a superlens.

[0017] In an exemplary embodiment of the present application, the outcoupling optical waveguide device comprises: a second substrate; at least two second couplers; at least two second optical waveguides;

[0018] The second coupler and the second optical waveguide are arranged on the second substrate, and the second coupler and the second optical waveguide are matched one to one;

[0019] The second optical waveguide is used to couple the output light from the calculation layer to the corresponding second coupler, and the second coupler is used to emit the output light to the detector array;

[0020] The second optical waveguide is matched with the first optical waveguide one by one.

[0021] In an exemplary embodiment of the present application, the second coupler is disposed at an end of the second optical waveguide for emitting output light.

[0022] In an exemplary embodiment of the present application, the output port comprises: an outcoupling lens array;

[0023] The outcoupling lens array includes at least two outcoupling lenses, and the outcoupling lenses are microlenses or superlenses.

[0024] In an exemplary embodiment of the present application, the outcoupling lens and the second coupler are matched one-to-one.

[0025] In an exemplary embodiment of the present application, the outcoupling lens array is arranged downstream of the optical path of the output light;

[0026] The outcoupling lens array is used to receive output light without crosstalk and collimate the output light.

[0027] According to one aspect of an embodiment of the present application, a three-dimensional port for a three-dimensional optical neural network is disclosed, characterized in that the three-dimensional port includes: a three-dimensional input port and a three-dimensional output port;

[0028] Wherein, the three-dimensional input port is used to receive input light and transmit the input light to the three-dimensional computing layer of the three-dimensional optical neural network;

[0029] The three-dimensional output port is used to receive output light from the three-dimensional computing layer and transmit the output light to a detector array for receiving the output light;

[0030] The three-dimensional input port includes a coupling optical waveguide array and a three-dimensional coupling lens array, wherein the three-dimensional coupling lens array is arranged upstream of the optical path of the input light; the three-dimensional coupling lens array includes at least two coupling lenses;

[0031] The three-dimensional output port includes an outcoupling optical waveguide array.

[0032] In an exemplary embodiment of the present application, the coupling-in optical waveguide array is formed by vertically stacking and packaging at least two coupling-in optical waveguide devices, and the coupling-out optical waveguide array is formed by vertically stacking and packaging at least two coupling-out optical waveguide devices;

[0033] The coupling-in optical waveguide device in the coupling-in optical waveguide array is matched one-to-one with the coupling-out optical waveguide device in the coupling-out optical waveguide array, and the first optical waveguide in the coupling-in optical waveguide device is matched one-to-one with the second optical waveguide in the coupling-out optical waveguide device.

[0034] In an exemplary embodiment of the present application, the coupling-in optical waveguide components in the coupling-in optical waveguide array and the coupling-out optical waveguide components in the coupling-out optical waveguide array are both staggered.

[0035] In an exemplary embodiment of the present application, the three-dimensional coupling lens array includes at least two coupling lenses with different focal lengths.

[0036] In an exemplary embodiment of the present application, the three-dimensional output port comprises: a three-dimensional outcoupling lens array;

[0037] The three-dimensional outcoupling lens array includes at least two outcoupling lenses with different focal lengths.

[0038] In an exemplary embodiment of the present application, the three-dimensional outcoupling lens array is arranged downstream of the optical path of the output light;

[0039] The three-dimensional outcoupling lens is used to receive output light without crosstalk and collimate the output light.

[0040] According to one aspect of an embodiment of the present application, an optical neural network is disclosed, wherein the optical neural network includes a port provided in any one of the above embodiments.

[0041] According to one aspect of an embodiment of the present application, a three-dimensional optical neural network is disclosed, wherein the three-dimensional optical neural network includes a three-dimensional port provided in any one of the above embodiments.

[0042] The port for optical neural network provided by the present application includes: an input port and an output port; wherein the input port is used to receive input light and transmit the input light to the computing layer of the optical neural network; the output port is used to receive output light from the computing layer and emit the output light to a detector array for receiving the output light; the input port includes an in-coupling optical waveguide device and an in-coupling lens array, wherein the in-coupling lens array is arranged upstream of the optical path of the input light; the in-coupling lens array includes at least two in-coupling lenses; the output port includes an out-coupling optical waveguide device. The three-dimensional port for three-dimensional optical neural network includes: a three-dimensional input port and a three-dimensional output port; wherein the three-dimensional input port is used to receive input light and transmit the input light to the three-dimensional computing layer of the three-dimensional optical neural network; the three-dimensional output port is used to receive output light from the three-dimensional computing layer and emit the output light to a detector array for receiving the output light; the three-dimensional input port includes an in-coupling optical waveguide array and a three-dimensional in-coupling lens array, wherein the three-dimensional in-coupling lens array is arranged upstream of the optical path of the input light; the three-dimensional in-coupling lens array includes at least two in-coupling lenses; the three-dimensional output port includes an out-coupling optical waveguide array. By using an input lens to focus the input light and an output lens to collimate the output light, the optical neural network and the three-dimensional optical neural network can achieve independent input and output, reduce the loss of input and output light, improve the energy efficiency of the entire optical neural network, and enhance the parallel processing capability of the three-dimensional optical neural network.

[0043] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0044] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The above and other objects, features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0046] Figure 1 A schematic diagram of an input port in an embodiment of the present application is shown.

[0047] Figure 2 A schematic diagram showing the operation of an input port in an embodiment of the present application is shown.

[0048] Figure 3 A schematic diagram showing the operation of an output port in an embodiment of the present application is shown.

[0049] Figure 4 A first structural schematic diagram of a three-dimensional input port in an embodiment of the present application is shown.

[0050] Figure 5 A second structural schematic diagram of a three-dimensional input port in an embodiment of the present application is shown.

[0051] Figure 6 A third structural schematic diagram of a three-dimensional input port in an embodiment of the present application is shown.

[0052] Figure 7 A first working principle diagram of a three-dimensional input port in an embodiment of the present application is shown.

[0053] Figure 8 A second working principle diagram of a three-dimensional input port in an embodiment of the present application is shown.

[0054] Fig. 9 A first working principle diagram of a three-dimensional output port in an embodiment of the present application is shown.

[0055] Fig.10 A second working principle diagram of a three-dimensional output port in an embodiment of the present application is shown.

[0056] Reference numerals:

[0057] 1-first substrate; 2-first optical waveguide; 3-first coupler; 4-coupling lens array; 5-coupling lens; 6-input light; 7-output light; 8-three-dimensional coupling lens array; 9-coupling optical waveguide array. DETAILED DESCRIPTION

[0058] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of the present application will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0059] In addition, the described features, structures or characteristics may be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present application. However, those skilled in the art will appreciate that the technical solution of the present application may be practiced while omitting one or more of the specific details, or other methods, components, steps, etc. may be adopted. In other cases, known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring the present application and making the various aspects of the present application obscure.

[0060] Some of the blocks shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processing unit devices and / or microcontroller devices.

[0061] In order to ensure that the input light can be accurately transmitted to the computing module in the optical neural network, the related technology usually directly projects the input light onto the input port. The input port cannot receive all the input light, resulting in part of the input light being unable to be transmitted into the optical path of the optical neural network, thereby causing loss of the input light; after the input port transmits the input light to the computing module and the computing module completes the corresponding optical calculation, the computing module will output the corresponding output light. The related technology usually directly emits the output light through the output port, but since the output light has a divergence angle, after a certain distance, crosstalk will occur between multiple output lights, thereby affecting the calculation accuracy and stability of the optical neural network.

[0062] In order to overcome the above-mentioned defects of the related art, the present application provides a port for an optical neural network, which can realize independent input and output of multiple couplers.

[0063] The ports provided in this application include: input ports and output ports.

[0064] Specifically, the input port is used to receive input light and transmit the input light to the computing layer of the optical neural network. The working band of the input light can be one or more of the visible light band, the near infrared band and the terahertz band, or it can be an optical signal of other working bands, which will not be described in detail here.

[0065] In the present application, the calculation layer is a module that uses input light to perform corresponding optical calculations. In one embodiment of the present application, the calculation layer can be implemented using the diffraction of light. In another embodiment of the present application, the calculation layer can be implemented using the interference of light.

[0066] For the sake of ease of explanation, the computing layer of the optical neural network in the embodiment of the present application is implemented in a diffraction manner, that is, the computing layer of the optical neural network is one or more diffraction layers, and the optical neural network is a diffraction neural network. However, it should be noted that this is only used for the subsequent description of the present application and does not mean that the optical neural network of the present application is limited to a diffraction neural network.

[0067] The output port is used to receive the output light from the computing layer and transmit the output light to the detector array for receiving the output light. Taking the diffraction neural network as an example, the computing layer in the diffraction neural network uses the input light to simulate the forward propagation process in the fully connected neural network; according to the Fresnel diffraction theorem, when the input light passes through the diffraction layer, it can be propagated again to the next diffraction layer as a secondary radiation source. In other words, the input light completes all network matrix operations during the diffraction process, and is modulated into the corresponding output light, and is sent to the pre-set detector array through the output port. Finally, the content detected by the detector array is analyzed to obtain the final light calculation result.

[0068] It should be noted that, in the present application, the content detected by the detector array is matched one-to-one with the encoding method of the input light.

[0069] In an embodiment of the present application, if the encoding method of the input light is phase encoding, the content detected by the detector array is the phase distribution formed by the output light on the detector array.

[0070] In an embodiment of the present application, if the encoding method of the input light is wavelength encoding, the content detected by the detector array is the wavelength distribution formed by the output light on the detector array.

[0071] In an embodiment of the present application, if the encoding method of the input light is amplitude encoding, the content detected by the detector array is the energy distribution formed by the output light on the detector array.

[0072] The input port includes a coupling optical waveguide device and a coupling lens array. In the embodiment of the present application, the coupling lens array is used to focus the received input light so that the input light can be accurately focused into the coupler on the coupling optical waveguide device. The coupling optical waveguide device is used to transmit the input light and guide the input light to the computing layer of the optical neural network. Therefore, the coupling lens array should be set upstream of the optical path of the input light, and the coupling optical waveguide device should be set at one times the focus of the coupling lens. In detail, the coupling lens array includes at least two coupling lenses; the coupling lens can be a microlens or a superlens. In the embodiment of the present application, it can be selected according to actual needs.

[0073] In one embodiment of the present application, the coupling lens array can be composed of a plurality of microlenses. Commonly used manufacturing materials include polydimethylsiloxane, polymethyl methacrylate, photoresist and silicon dioxide, etc. The material, shape, curvature, array arrangement and other parameters of each microlens can be adjusted to achieve specific optical functions.

[0074] In one embodiment of the present application, the coupling lens array can be composed of a plurality of superlenses, which are planar optical lenses with surface micro-nano structures. The material of the surface micro-nano structures varies depending on the working band. For example, when the working band of the superlens is the near-infrared band, the material of the nanostructure may include one or more of silicon nitride, titanium oxide, gallium nitride, gallium phosphide, hydrogenated amorphous silicon, amorphous silicon and crystalline silicon; when the working band of the superlens is the visible light band, the material of the nanostructure may include one or more of fused quartz, quartz glass, crown glass, flint glass, sapphire and alkaline glass; when the working band of the superlens is the far-infrared band, the material of the nanostructure includes one or more of crystalline silicon, crystalline germanium, zinc sulfide and zinc selenide. Compared with microlenses, superlenses are lighter, thinner and have lower production costs. For each superlens, the material, shape, characteristic size, filling material and other parameters of the surface micro-nano structure can be adjusted to achieve specific optical functions.

[0075] For example, in the present application, the focal length of the coupling lens determines the setting position of the coupling lens array and the coupling optical waveguide device. The setting position of the coupling lens array should satisfy: each coupling lens on the coupling lens array is a coupling optical waveguide device at one focal length. It should be emphasized that the one focal length in the embodiment of the present application does not refer to the one focal length position in a strict sense, but is within a reasonable tolerance range near one focal length. It can be understood that if the focal length of the coupling lens is f, then the one focal length can be expressed as: f±Δx, Δx represents a reasonable tolerance. The output port includes an out-coupling optical waveguide device, which is used to output the output light to the detector array for detecting the signal.

[0076] Figure 1A schematic diagram showing an input port for an optical neural network provided in the present application is shown, see Figure 1 In an embodiment of the present application, the coupling optical waveguide device includes: a first substrate 1; at least two first optical waveguides 2; at least two first couplers 3. The input port also includes: a coupling lens array 4; a coupling lens 5. In detail, the first coupler 3 and the first optical waveguide 2 are arranged on the first substrate 1, and the first coupler 3 and the first optical waveguide 2 are matched one by one; that is, each first optical waveguide 2 has a first coupler 3 corresponding thereto. The first coupler 3 is used to receive input light, and the first optical waveguide 2 is used to couple the input light to the computing layer of the optical neural network. Since the first coupler 3 is an optical device for receiving input light, the first coupler 3 is arranged at one end of the first optical waveguide 2 for receiving input light.

[0077] Further, in one embodiment of the present application, see Figure 1 , Figure 1 It is shown that ten first optical waveguides are arranged at a preset interval on the first substrate. It should be noted that the number of the first optical waveguides and the preset intervals between the first optical waveguides can be set by technicians according to actual needs; and, although Figure 1 The first optical waveguide shown in the figure is arranged in a straight line, but in another embodiment, the first optical waveguide can be arranged in a folded line or in any other form. In other words, the specific arrangement form of the first optical waveguide is not limited in this application, and the first optical waveguide can finally guide the input light to the computing layer.

[0078] In one embodiment, the coupling lens array includes at least two coupling lenses, and the coupling lenses and the first couplers are matched one-to-one, that is, the coupling lenses are used to focus the input light onto the corresponding first couplers; therefore, the first coupler should be located at one focal length of the coupling lenses.

[0079] Figure 2 FIG. 2 shows a schematic diagram of the operation of the input port in an embodiment of the present application. Figure 2In the embodiment of the present application, the focusing lens array focuses the input light 6 onto a plurality of first couplers respectively, and then guides the input light through the first optical waveguide connected to each first coupler, thereby sending the input light to the computing layer in the optical neural network; it should be emphasized that since the function of the coupling lens array is only to focus the input light so that the input light can be accurately focused onto the corresponding first coupler, in the embodiment of the present application, it can be understood that the distance from the coupling lens to the first coupler is equal to the focal length of the coupling lens. It should be noted that in one embodiment of the present application, the focal lengths of all coupling lenses in the coupling lens array are the same, that is, the distance from each coupling lens to the corresponding first coupler is also the same, which is equal to the focal length; in another embodiment of the present application, the focal length of each coupling lens in the coupling lens array may also be different, and accordingly, the distance from each coupling lens to the corresponding first coupler is also different, which is respectively equal to the corresponding focal length.

[0080] It should be emphasized that the distance equal to the focal length in the above embodiment does not mean that the distance is strictly equal to the focal length, and the distance may also be equal to the focal length plus / minus a reasonable tolerance.

[0081] In one embodiment, the out-coupling optical waveguide device of the output port comprises: a second substrate; at least two second couplers; at least two second optical waveguides; in fact, the structure of the out-coupling optical waveguide device is similar to that of the in-coupling optical waveguide device, the second coupler and the second optical waveguide are arranged on the second substrate, and the second coupler and the second optical waveguide are matched one by one. The second optical waveguide is used to couple the output light from the computing layer to the corresponding second coupler, and the second coupler is used to emit the output light to the detector array, so the difference between the out-coupling optical waveguide device and the in-coupling optical waveguide device is only that the second coupler on the out-coupling optical waveguide device is arranged at one end of the second optical waveguide for emitting the output light.

[0082] It should be emphasized that the second optical waveguide on the out-coupling optical waveguide device is matched one-to-one with the first optical waveguide on the in-coupling optical waveguide device. In the actual working process of the optical neural network, all the first optical waveguides on the in-coupling optical waveguide device first guide the input light to the computing layer, and the computing layer modulates each beam of input light to obtain multiple beams of output light; there is a second optical waveguide on the out-coupling optical waveguide device corresponding to each first optical waveguide device on the in-coupling optical waveguide device, that is, each second optical waveguide will receive the output light corresponding to the corresponding first optical waveguide, and then transmit each beam of output light to the second coupler connected to each second optical waveguide, and then the second coupler will emit the output light.

[0083] In another embodiment of the present application, the first optical waveguide and the second optical waveguide can also be regarded as the same optical waveguide, the computing layer is arranged in the middle position of this optical waveguide, the first coupler is arranged at one end of this optical waveguide for receiving input light, and the second coupler is arranged at one end of this optical waveguide for emitting output light.

[0084] It should be noted that in one embodiment of the present application, the output port does not include a coupling lens array, and a detector array is directly arranged downstream of the second coupler of the coupling optical waveguide device along the optical propagation direction, and the output light is directly received by the detector array.

[0085] In another embodiment of the present application, the output port may also include an outcoupling lens array; the outcoupling lens array includes at least two outcoupling lenses, and the outcoupling lens and the incoupling lens are similar and may also be microlenses or superlenses.

[0086] Specifically, Figure 3 FIG. 2 shows a schematic diagram of the operation of the output port in an embodiment of the present application. Figure 3 , the outcoupling lens and the second coupler are matched one by one. Figure 3 The dotted arrow in the figure indicates the propagation direction of the optical path. At this time, the optical path is the output light 7 output by the computing layer. After being transmitted through the second optical waveguide, the output light 7 reaches the second coupler connected to the second optical waveguide. The second coupler emits the output light. Each outcoupling lens in the outcoupling lens array modulates the output light emitted by the corresponding second coupler. The output light then travels to the detector array arranged downstream of the outcoupling lens array along the light propagation direction.

[0087] Since the output light emitted by the second coupler has a divergence angle, the function of each outcoupling lens in the outcoupling lens array is to collimate the output light emitted by the corresponding second coupler. Therefore, similar to the coupling-in lens, the second coupler is located at one focal length of the corresponding outcoupling lens.

[0088] Furthermore, since the output light has a divergence angle, after traveling a certain distance in the direction of optical propagation, crosstalk will occur between multiple output lights. Therefore, it is necessary to limit the position setting of the outcoupling lens array downstream of the outcoupling optical waveguide device along the optical propagation path, that is, it is necessary to limit the distance between the outcoupling lens and the second optical waveguide device, which is equivalent to limiting the focal length of the outcoupling lens, so as to avoid crosstalk between the output lights.

[0089] In order to solve the above-mentioned crosstalk problem between the output lights, in one embodiment of the present application, considering the different divergence angles of different output lights, the specific setting position of the coupling lens array needs to satisfy that each output light will not generate crosstalk with another output light, that is, the distance between each coupling lens and the corresponding second coupler needs to satisfy: the output light emitted by the second coupler reaches the corresponding coupling lens before generating crosstalk with any other output light. It can be understood that no matter where the coupling lens array is set, as long as all the output lights received by the coupling lens array are crosstalk-free, each output light can be collimated separately. Thereby, the coupling lens array can collimate the output light before the output light generates crosstalk, avoiding the decrease in the calculation accuracy of the optical neural network due to the output light crosstalk. Correspondingly, the detector array is set downstream of the coupling lens array along the propagation direction of the optical path, and is used to receive the output light collimated by the coupling lens array.

[0090] It should be noted that, in the case where the output port does not include an outcoupling lens array, if the loss of the output light is not considered, the detector array can be set at any position downstream of the output light path, as long as the detector array can receive the output light. If the loss of the output light is considered, the detector array should be set at the same position as the outcoupling lens array, that is, all the output light is received before the output light generates crosstalk.

[0091] It should be noted that when the coupling-in / coupling-out lens is a metalens, the phase of the first / second coupler is expressed as:

[0092]

[0093] Wherein, φ(x, y) is the phase of the first coupler or the second coupler, φ(x, y) is the position on the planar metalens, λ represents the working band of the input light, and f is the focal length of the coupling-in / coupling-out lens; in the embodiments of the present application, the focal lengths of all coupling-in / coupling-out lenses using metalens are calculated by this formula.

[0094] In one embodiment, the first / second substrate, the first / second coupler, the first / second optical waveguide and the coupling-in / coupling-out lens are all made of materials with high transmittance in the working wavelength band. For example, if the central wavelength of the input light wavelength band is 1550 nm, the first coupler and its corresponding first optical waveguide are made of polysilicon, and the substrate may be quartz glass.

[0095] The optical neural network in the present application can be regarded as a two-dimensional optical neural network, and multiple optical neural networks can constitute a three-dimensional optical neural network; the three-dimensional optical neural network can perform multiple tasks in parallel, so the input and output of the three-dimensional optical neural network need to be independent input and output.

[0096] To this end, the present application provides a three-dimensional port for a three-dimensional optical neural network, the three-dimensional port comprising: a three-dimensional input port and a three-dimensional output port. The three-dimensional input port is used to receive input light and transmit the input light to the three-dimensional computing layer of the three-dimensional optical neural network. The three-dimensional output port is used to receive output light from the three-dimensional computing layer and emit the output light to a detector array for receiving the output light.

[0097] It should be noted that, in one embodiment of the present application, the three-dimensional optical neural network is composed of multiple two-dimensional optical neural networks, and the composition method includes but is not limited to vertical stacking. Therefore, the three-dimensional computing layer can be understood as a vertical stacking of computing layers of multiple two-dimensional optical neural networks. For example, the optical neural network is a diffraction neural network, and the computing layer therein is a diffraction layer combination composed of multiple diffraction layers. Then, in the propagation direction perpendicular to the optical path, the stacking arrangement of each two-dimensional diffraction neural network can obtain a three-dimensional diffraction neural network; the three-dimensional computing layer of the three-dimensional diffraction neural network is also correspondingly composed of a combination of multiple diffraction layers.

[0098] In detail, Figure 4 shows a first structural schematic diagram of a three-dimensional input port in an embodiment of the present application, Figure 5 shows a second structural schematic diagram of a three-dimensional input port in an embodiment of the present application, Figure 6 FIG. 3 shows a third structural diagram of a three-dimensional input port in an embodiment of the present application. Figures 4 to 6 In one embodiment, the three-dimensional input port includes an incoupling optical waveguide array 9 and a three-dimensional incoupling lens array 8, wherein the three-dimensional incoupling lens array 8 is arranged upstream of the optical path of the output light; the three-dimensional incoupling lens array 8 includes at least two incoupling lenses. The three-dimensional output port includes an outcoupling optical waveguide array.

[0099] In one embodiment, the coupling-in optical waveguide array is formed by vertically stacking and packaging at least two coupling-in optical waveguide devices, and the coupling-out optical waveguide array is formed by vertically stacking and packaging at least two coupling-out optical waveguide devices. Figure 4 As shown, the coupling-in optical waveguide array includes a plurality of first optical waveguides and a first coupler connected to each first optical waveguide. Similarly, the coupling-out optical waveguide array also includes a plurality of second optical waveguides and a second coupler connected to each second optical waveguide.

[0100] It should be emphasized that in the three-dimensional optical neural network, the coupling optical waveguide device in the coupling optical waveguide array is matched one-to-one with the coupling optical waveguide device in the coupling optical waveguide array. The specific matching method is layer-to-layer matching. For example, perpendicular to the optical path propagation direction of the input light, the coupling optical waveguide device located at the most upstream is matched one-to-one with the coupling optical waveguide device located at the most downstream, and so on. Moreover, the first optical waveguide and the second optical waveguide in the coupling optical waveguide device and the coupling optical waveguide device that are matched one-to-one are consistent with the two-dimensional optical neural network and are also matched one-to-one. That is to say, the first optical waveguide and the second optical waveguide in the coupling optical waveguide device and the coupling optical waveguide device located in the same layer are matched one-to-one.

[0101] In detail, Figure 7 shows a first working principle diagram of a three-dimensional input port in an embodiment of the present application, Fig. 9 FIG. 1 shows a first working principle diagram of a three-dimensional output port in an embodiment of the present application. Figure 7 and Fig. 9 ,Depend on Figure 7 and Fig. 9 It can be obtained that the optical path propagation direction of the input light is perpendicular to the coupling optical waveguide array, and the optical path propagation direction of the output light is perpendicular to the coupling optical waveguide array. Therefore Figure 7 The upstream coupling optical waveguide device and Fig. 9 The downstream outcoupling optical waveguide device is one-to-one matched. Figure 7 The downstream coupling optical waveguide device and Fig. 9 The out-coupling optical waveguide devices in the second upstream are matched one by one. Figure 7 The downstream coupling optical waveguide device and Fig. 9 The most upstream out-coupling optical waveguide device is matched one by one, and so on, the remaining out-coupling / out-coupling optical waveguide devices are also matched one by one in layers.

[0102] It should be noted that, since the three-dimensional input port needs to use the first coupler on the coupling-in optical waveguide device or the second coupler on the coupling-out optical waveguide device when receiving input light or the three-dimensional output port needs to use the first coupler on the coupling-in optical waveguide device or the second coupler on the coupling-out optical waveguide device when emitting output light, the first couplers on the coupling-in optical waveguide devices at different layers cannot overlap or block each other; similarly, the second couplers on the coupling-out optical waveguide devices at different layers cannot overlap or block each other; therefore, see Figures 4 to 6 In one embodiment, the coupling-in optical waveguide device in the coupling-in optical waveguide array and the coupling-out optical waveguide device in the coupling-out optical waveguide array are both staggered. The specific staggered arrangement can be as follows: Figures 4 to 6 The step-shaped structure shown in FIG. 1 does not mean that the coupling-in optical waveguide array or the coupling-out optical waveguide array provided by the present application is limited to Figures 4 to 6 The offset setting method shown.

[0103] In order to realize the independent input of multiple first couplers in the coupling optical waveguide array of the three-dimensional input port, in one embodiment of the present application, the three-dimensional input port further includes a three-dimensional coupling lens array, and each coupling lens in the three-dimensional coupling lens array is matched one by one with each first coupler in the coupling optical waveguide array. Since the coupling optical waveguide array is composed of multiple coupling optical waveguide devices vertically packaged and staggered, Figure 4 and Figure 6 As shown, when the three-dimensional coupling lens array is arranged in parallel with the coupling optical waveguide device in the coupling optical waveguide array, the distances from the coupling lenses in the three-dimensional coupling lens array to the first couplers located at different layers are different, that is, the focal lengths of the coupling lenses applied to the coupling optical waveguide devices at different layers are different; therefore, the three-dimensional coupling lens array in this embodiment includes at least two coupling lenses with different focal lengths, so as to achieve focusing of the input light of the coupling optical waveguide devices at different layers in the three-dimensional optical neural network, and all the coupling lenses and all the first couplers in the three-dimensional coupling lens array are matched one by one and have no overlap.

[0104] In detail, Figure 8 FIG. 2 shows a second working principle diagram of a three-dimensional input port in an embodiment of the present application. Figure 7 and Figure 8 In the embodiment of the present application, the input light is focused by each coupling lens in the three-dimensional coupling lens array. Due to the difference in focal lengths, the incident light can be focused into the first couplers of different layers to achieve independent input of the three-dimensional optical neural network. Moreover, since the function of the focusing lens array is only to focus the input light, the distance between each coupling lens in the three-dimensional coupling lens array and the corresponding first coupler should be equal to the focal length.

[0105] It should be emphasized that the distance equal to the focal length in the above embodiment does not mean that the distance is strictly equal to the focal length, and the distance may also be equal to the focal length plus / minus a reasonable tolerance.

[0106] Furthermore, similar to the output port of the two-dimensional optical neural network, the three-dimensional output port used for the three-dimensional optical neural network can also choose whether to set a corresponding three-dimensional coupling lens array between the detector array and the coupling optical waveguide array according to actual needs.

[0107] In one embodiment of the present application, a corresponding detector array can be directly set downstream of the outcoupling optical waveguide array of the three-dimensional output port along the optical path propagation direction, and the output light emitted by each second coupler in the outcoupling optical waveguide array is directly received by the detector array.

[0108] In another embodiment of the present application, the three-dimensional output port may include a three-dimensional outcoupling lens array. Since the outcoupling optical waveguide array is vertically stacked and packaged and staggered, the three-dimensional outcoupling lens array includes at least two outcoupling lenses with different focal lengths, which are used to collimate the output light emitted by the second coupler of the outcoupling optical waveguide device at different layers.

[0109] It should be emphasized that, consistent with the output port for the two-dimensional optical neural network, due to the divergence angle of the output light, crosstalk will occur after traveling a certain distance along the optical path. In order to avoid crosstalk in the output light emitted by the multiple second couplers in the outcoupling optical waveguide array, in one embodiment of the present application, the three-dimensional outcoupling lens array is set downstream of the outcoupling optical waveguide array along the optical path propagation direction of the output light to limit the position.

[0110] In detail, the output light of the outcoupling optical waveguide array has any of the following conditions:

[0111] (1) The divergence angles of the output lights emitted by all the second couplers in the outcoupling optical waveguide array are the same;

[0112] (2) The divergence angle of the output light emitted by each layer of the second coupler in the outcoupling optical waveguide array is the same, but the divergence angle is the same as / different from the divergence angle of the output light emitted by any other layer of the second coupler;

[0113] (3) The divergence angle of the output light emitted by each second coupler in the outcoupling optical waveguide array is different.

[0114] For any of the above situations, the specific setting position of the three-dimensional outcoupling lens array needs to satisfy the situation that each beam of output light will not generate crosstalk with another beam of output light, that is, similar to the outcoupling lens array, no matter where the three-dimensional outcoupling lens array is set, as long as all the output lights received by the three-dimensional outcoupling lens array are crosstalk-free. The detector array is set downstream of the three-dimensional outcoupling lens array along the optical path propagation direction of the output light, and is used to receive the output light after collimation by the three-dimensional outcoupling lens array.

[0115] It should be noted that, in the case where the three-dimensional output port does not include a three-dimensional outcoupling lens array, if the loss of the output light is not considered, the detector array can be set at any position downstream of the output light path, as long as the detector array can receive the input light. If the loss of the output light is considered, the setting position of the detector array should also meet the same conditions as the setting position of the three-dimensional outcoupling lens array, that is, a position where no crosstalk is generated between all output lights.

[0116] Fig.10 FIG. 2 shows a second working principle diagram of a three-dimensional output port in an embodiment of the present application. Figure 8 and Fig.10 In one embodiment of the present application, the complete workflow of the three-dimensional optical neural network is as follows: each first coupler on each layer of the coupled optical waveguide device in the coupled optical waveguide array receives input light respectively, and then transmits each input light to the three-dimensional computing layer through the corresponding first optical waveguide. The three-dimensional computing layer performs corresponding optical computing steps on each input light to obtain multiple corresponding output lights. The second optical waveguide matched with each first optical waveguide receives the output light corresponding to the first optical waveguide, and transmits each output light to the connected second coupler respectively. Each output light is emitted to the corresponding coupling lens in the three-dimensional coupling lens array through each second coupler. Each coupling lens collimates the output light respectively, and the collimated output light travels along the propagation direction of the optical path and reaches the detector array.

[0117] It should be noted that Figures 4 to 9 The three-dimensional coupling-in lens array and the three-dimensional coupling-out lens array shown in the figure are both composed of multiple coupling-in / coupling-out lenses arranged on the same horizontal plane, but this does not mean that the three-dimensional coupling-in lens array and the three-dimensional coupling-out lens array provided by the present application are limited to this. The three-dimensional coupling-in lens array can be composed of multiple coupling-in lens arrays, and the height position of each coupling-in lens array can be different, as long as the input light can be accurately focused to the corresponding first coupler; the three-dimensional coupling-out lens array can also be composed of multiple coupling-out lens arrays, and the height position of each coupling-out lens array can be different, as long as all output lights can be collimated without generating crosstalk.

[0118] The present application also provides an optical neural network, which includes the port for the optical neural network as described above.

[0119] The present application also provides a three-dimensional optical neural network, which includes the three-dimensional port for the three-dimensional optical neural network as described above.

[0120] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the utility model disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the appended claims.

Claims

1. A port for an optical neural network, characterized in that The ports include: an input port and an output port; Wherein, the input port is used to receive input light and transmit the input light to the computing layer of the optical neural network; The output port is used to receive the output light from the computing layer and transmit the output light to a detector array for receiving the output light; The input port comprises a coupling optical waveguide device and a coupling lens array, wherein the coupling lens array is arranged upstream of the optical path of the input light; the coupling lens array comprises at least two coupling lenses; The output port includes an out-coupling optical waveguide device.

2. The port according to claim 1, characterized in that The coupling-in optical waveguide device comprises: a first substrate; at least two first couplers; at least two first optical waveguides; The first coupler and the first optical waveguide are arranged on the first substrate, and the first coupler and the first optical waveguide are matched one by one; The first coupler is used to receive input light, and the first optical waveguide is used to couple the input light to the computing layer.

3. The port according to claim 2, characterized in that The first coupler is disposed at one end of the first optical waveguide for receiving the input light.

4. The port according to claim 2, characterized in that The coupling-in lens and the first coupler are matched one by one; The coupling lens is used to focus the input light onto the first coupler.

5. The port according to claim 1, characterized in that The coupling-in lens is a microlens or a superlens.

6. The port according to claim 2, characterized in that The out-coupling optical waveguide device comprises: a second substrate; at least two second couplers; at least two second optical waveguides; The second coupler and the second optical waveguide are arranged on the second substrate, and the second coupler and the second optical waveguide are matched one to one; The second optical waveguide is used to couple the output light from the calculation layer to the corresponding second coupler, and the second coupler is used to emit the output light to the detector array; The second optical waveguide is matched one-to-one with the first optical waveguide.

7. The port according to claim 6, characterized in that The second coupler is disposed at one end of the second optical waveguide for emitting output light.

8. The port according to claim 6, characterized in that The output port comprises: an outcoupling lens array; The outcoupling lens array includes at least two outcoupling lenses, and the outcoupling lenses are microlenses or superlenses.

9. The port according to claim 8, characterized in that The outcoupling lens and the second coupler are matched one by one.

10. The port according to claim 9, characterized in that The outcoupling lens array is arranged downstream of the optical path of the output light; The outcoupling lens array is used to receive output light without crosstalk and collimate the output light.

11. A three-dimensional port for a three-dimensional optical neural network based on the port according to any one of claims 1 to 10, characterized in that: The three-dimensional port includes: a three-dimensional input port and a three-dimensional output port; Wherein, the three-dimensional input port is used to receive input light and transmit the input light to the three-dimensional computing layer of the three-dimensional optical neural network; The three-dimensional output port is used to receive output light from the three-dimensional computing layer and transmit the output light to a detector array for receiving the output light; The three-dimensional input port includes a coupling optical waveguide array and a three-dimensional coupling lens array, wherein the three-dimensional coupling lens array is arranged upstream of the optical path of the input light; the three-dimensional coupling lens array includes at least two coupling lenses; The three-dimensional output port includes an outcoupling optical waveguide array.

12. The three-dimensional port according to claim 11, characterized in that: The coupling-in optical waveguide array is formed by vertically stacking and packaging at least two coupling-in optical waveguide devices, and the coupling-out optical waveguide array is formed by vertically stacking and packaging at least two coupling-out optical waveguide devices; The coupling-in optical waveguide device in the coupling-in optical waveguide array is matched one-to-one with the coupling-out optical waveguide device in the coupling-out optical waveguide array, and the first optical waveguide in the coupling-in optical waveguide device is matched one-to-one with the second optical waveguide in the coupling-out optical waveguide device.

13. The three-dimensional port according to claim 12, characterized in that: The coupling-in optical waveguide components in the coupling-in optical waveguide array and the coupling-out optical waveguide components in the coupling-out optical waveguide array are both staggered.

14. The three-dimensional port according to claim 11, characterized in that: The three-dimensional coupling lens array includes at least two coupling lenses with different focal lengths.

15. The three-dimensional port according to claim 11, characterized in that: The three-dimensional output port comprises: a three-dimensional outcoupling lens array; The three-dimensional outcoupling lens array includes at least two outcoupling lenses with different focal lengths.

16. The three-dimensional port according to claim 15, characterized in that: The three-dimensional outcoupling lens array is arranged downstream of the optical path of the output light; The three-dimensional outcoupling lens is used to receive output light without crosstalk and collimate the output light.

17. An optical neural network, characterized in that: The optical neural network comprises a port as described in any one of claims 1-10.

18. A three-dimensional optical neural network, characterized in that: The three-dimensional optical neural network includes the three-dimensional port as described in any one of claims 11-16.

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