WO2022016894A1 - Photonic neural network - Google Patents

Abstract

A photonic neural network, comprising: a light transmitting module which, on the basis of modulation of a signal to be processed, obtains optical signals of a first array; a light signal processing module which is coupled to the light transmitting module to receive the optical signals of the first array, the light signal processing module at least performing a linear operation on the optical signals of the first array to obtain optical signals of a second array, wherein for each beam of optical signal in the optical signals of the first array, the light signal processing module performs the linear operation on light of wavelengths in the optical signals independently; and a light receiving module which is coupled to the light signal processing module to receive the optical signals of the second array, the light receiving module obtaining the processed signals on the basis of the optical signals of the second array. The solution of the present invention can greatly improve the computing power and flexibility of a photonic artificial intelligence chip.

Description

A photonic neural network

This application claims the priority of the Chinese patent application filed with the China Patent Office on July 20, 2020, with the application number of 2020107007562 and the invention titled "A Photonic Neural Network", the entire contents of which are incorporated into this application by reference.

technical field

The invention relates to the technical field of photonic artificial intelligence chips, in particular to a photonic neural network.

Background technique

In the most popular deep learning in the field of artificial intelligence today, its operation process mainly involves two parts: matrix multiplication and nonlinear activation function. Specifically, artificial intelligence algorithms have the characteristics that the processing content is unstructured data (such as video, image or voice), the processing process requires a large number of linear algebra operations, and the processing process parameters are large. The computing hardware based on the central processing unit cannot meet the computing power requirements of artificial intelligence, and can only be realized by artificial intelligence (Artificial intelligence, referred to as AI) chips. Specifically, an AI chip is a chip specially oriented to AI applications, and is an important physical base carrier of AI technology.

Currently, AI chips are mainly implemented based on Complementary Metal Oxide Semiconductor (CMOS) technology. As the size of integrated circuit devices continues to approach the physical limit, Moore's Law shows a slowing trend. At the same time, microelectronic processors have problems such as decreased energy efficiency ratio, limited clock frequency (difficult to exceed 6GHz), electronic crosstalk, high power consumption, and heat generation. It restricts the continued improvement of the performance of existing electronic AI chips.

In order to break through the problems faced by electronic chips in the field of AI, photonic artificial intelligence chips came into being. However, the current photonic artificial intelligence chip technology is still in its infancy, and there are still many deficiencies in the architecture design of photonic artificial intelligence chips, which cannot give full play to the advantages of photonic artificial intelligence chips.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is how to improve the computing power of the photonic artificial intelligence chip.

To solve the above technical problem, an embodiment of the present invention provides a photonic neural network, including: an optical transmission module, the optical transmission module modulates the optical signal of the first array according to the signal to be processed, wherein the optical signal of the first array is Each beam of optical signal in the signal includes light of multiple wavelengths; an optical signal processing module is coupled to the light emission module to receive the optical signals of the first array, and the optical signal processing module at least Perform a linear operation on the optical signals of the array to obtain the optical signals of the second array, wherein, for each beam of optical signals in the optical signals of the first array, the optical signal processing module processes the optical signals of each wavelength in the optical signals. The linear operation of light is performed independently; the light receiving module is coupled to the optical signal processing module to receive the optical signals of the second array, and the light receiving module obtains and processes the optical signals based on the second array. Signal.

Optionally, for each beam of optical signals in the optical signals of the first array, the optical signal processing module performs the linear operation on the light of each wavelength in the optical signal independently, which means: The optical signal processing module configures corresponding convolution kernels respectively for light of different wavelengths in the optical signal, and the linear operations of the respective convolution kernels for the light of respective corresponding wavelengths are independent of each other.

Optionally, the optical signal processing module includes: a linear matrix multiplication unit, configured to perform a multi-core parallel matrix multiplication operation on each optical signal in the optical signals of the first array, so as to obtain the second array of optical signals. optical signal.

Optionally, the linear matrix multiplication unit includes: a plurality of optical interference units connected in series and parallel to each other, wherein the interference arm of each optical interference unit is provided with a wavelength-sensitive phase shifter array, and the input arm of each optical interference unit is provided with a wavelength-sensitive phase shifter array. and at least one of the output arms is provided with the wavelength-sensitive phase shifter array to perform independent phase shifting operations on the light of each wavelength in the optical signal input to the optical interference unit.

Optionally, the optical signal processing module includes a plurality of cascaded linear matrix multiplication units, wherein the output of the linear matrix multiplication unit of the previous stage is the input of the linear matrix multiplication unit of the subsequent stage, and the first The input of the linear matrix multiplying unit of the first stage is the optical signal of the first array, and the output of the linear matrix multiplying unit of the last stage is the optical signal of the second array.

Optionally, the optical signal processing module further includes: an optical nonlinear unit, coupled to the linear matrix multiplication unit to receive a linear operation result of the linear matrix multiplication unit on the optical signals of the first array, and A nonlinear operation is performed on the linear operation result of the optical signal of the first array according to the optical signal of the reference array, so as to obtain the optical signal of the second array.

Optionally, the coupled linear matrix multiplication unit and the optical nonlinear unit are denoted as a neural network unit, and the optical signal processing module includes a plurality of cascaded neural network units, wherein the previous The output of the neural network unit of the first stage is the input of the neural network unit of the next stage, the input of the neural network unit of the first stage is the optical signal of the first array, and the output of the neural network unit of the last stage is the optical signal of the second array. Signal.

Optionally, the linear operation result of the optical signals of the first array is recorded as the optical signals of the fourth array, and the optical nonlinear unit performs nonlinear operations on the light of each wavelength in the optical signals of the fourth array. is carried out independently.

Optionally, the optical nonlinear unit includes: a plurality of optical interference units, wherein each optical interference unit receives the optical signal of the fourth array and the optical signal of the reference array respectively, the input arm of the optical interference unit and The interference arm is provided with a wavelength-sensitive phase shifter array to perform an independent nonlinear transformation operation on the light of each wavelength in the optical signal of the fourth array according to the optical signal of the reference array.

Optionally, the optical nonlinear unit includes: a plurality of optical interference units, wherein each optical interference unit receives the optical signal of the fourth array and the optical signal of the reference array respectively, and the input arm of the optical interference unit is set A wavelength-sensitive phase shifter array is provided to perform an independent nonlinear transformation operation on the light of each wavelength in the optical signal of the fourth array according to the optical signal of the reference array.

Optionally, the wavelength-sensitive phase shifter array includes a plurality of phase shifters, and the plurality of phase shifters correspond one-to-one with each wavelength of light in the input optical signal.

Optionally, the light emitting module includes: an optical signal array generation unit, the optical signal array generation unit is used to generate an optical signal array, and each beam of optical signals in the optical signal array includes a continuous wavelength of multiple wavelengths. light, the optical signal array generated by the optical signal array generating unit is recorded as the optical signal of the third array; the modulator array is coupled with the optical signal array generating unit to receive the optical signal of the third array, so The modulator array is configured to apply a modulation signal to the optical signals of the third array to obtain the optical signals of the first array, wherein the modulation signal is associated with the signal to be processed.

Optionally, the modulator array applies the same modulation signal to the light of each wavelength of the same beam of optical signals in the optical signals of the third array, and applies different beams of optical signals to the optical signals of the third array. modulation signal.

Optionally, the modulator array applies different modulation signals to light of different wavelengths of the same optical signal in the optical signals of the third array.

Optionally, the modulator array includes a plurality of multi-wavelength light modulator units, wherein each of the multi-wavelength light modulator units includes an optical interference unit, and the upper arm and the lower arm of the optical interference unit are respectively provided with wavelength sensitive units. The phase shifter array can independently modulate the light of each wavelength in the input optical signal.

Optionally, the wavelength-sensitive phase shifter array includes a plurality of phase shifters, and the plurality of phase shifters correspond to each wavelength of light in the input optical signal one-to-one.

Optionally, the sum of the phase shift parameters of the phase shifters corresponding to the same wavelength in the wavelength-sensitive phase shifter array arranged on the upper arm and the wavelength-sensitive phase shifter array arranged on the lower arm is an integer of 2π. multiple.

Optionally, the photonic neural network further includes: an electrical control module coupled to the light receiving module, and the electrical control module is configured to receive and adjust the processed signal.

Optionally, the electrical control module is further coupled to the light emission module, so as to transmit the adjusted processed signal to the light emission module as a signal to be processed.

Optionally, the photonic neural network is used for image processing, image recognition, speech recognition, gene sequencing, quantum communication or quantum computing.

Compared with the prior art, the technical solutions of the embodiments of the present invention have the following beneficial effects:

An embodiment of the present invention provides a photonic neural network, including: an optical transmission module, the optical transmission module modulates the optical signals of the first array according to the signal to be processed, wherein each beam of optical signals in the optical signals of the first array is The signal includes light of a plurality of wavelengths; an optical signal processing module is coupled to the optical transmission module to receive the optical signals of the first array, and the optical signal processing module at least linearizes the optical signals of the first array operation to obtain the optical signals of the second array, wherein, for each optical signal in the optical signals of the first array, the linear operation of the optical signal processing module on the light of each wavelength in the optical signal is independent To carry out: an optical receiving module coupled to the optical signal processing module to receive the optical signals of the second array, the optical receiving module obtaining the processed signals based on the optical signals of the second array.

Among them, the operation is independent of each other, which means that the parameters and/or operation algorithms used in the operation process are independent of each other and have no dependency relationship, and may be the same or different from each other, and may be related or not.

The solution of this embodiment can greatly improve the computing power and flexibility of the photonic artificial intelligence chip. Specifically, the existing photonic artificial intelligence chips perform linear operations on a single wavelength of light, or perform the same linear operations on each wavelength of light in the same optical signal, which leads to extremely limited computing power and flexibility of photonic neural networks. big limit. The solution of this embodiment makes it possible to perform multi-core parallel processing of the input light by independently performing linear operations on the light of each wavelength in the same optical signal, which is beneficial to improve the computing power and flexibility of the photonic artificial intelligence chip. Further, it can also improve the computing power of photonic artificial intelligence chips per unit area.

Further, for each beam of optical signals in the optical signals of the first array, the optical signal processing module performs the linear operation on the light of each wavelength in the optical signal independently, which means: the The optical signal processing module configures corresponding convolution kernels respectively for light of different wavelengths in the optical signal, and the linear operations of each convolution kernel for the light of respective corresponding wavelengths are independent of each other. Therefore, by independently setting up the convolution kernel for each wavelength, the calculation results of each wavelength will not affect each other. Further, the solution of this embodiment provides a multi-core parallel computing photonic neural network, which performs linear operations on the light of multiple wavelengths in the optical signal in parallel through multiple convolution cores, which greatly improves the overall computing speed and computing power. .

Description of drawings

1 is a schematic diagram of the principle of a photonic neural network according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a first specific embodiment of the light emission module in FIG. 1;

3 is a schematic structural diagram of a specific implementation manner of a single modulator in the modulator array shown in FIG. 2;

4 is a schematic structural diagram of a second specific implementation manner of the light emission module in FIG. 1;

FIG. 5 is a schematic structural diagram of a first specific implementation manner of the optical signal processing module in FIG. 1;

FIG. 6 is a schematic structural diagram of a first specific embodiment of the minimum basic unit of the optical signal processing module in FIG. 1;

FIG. 7 is a schematic structural diagram of a specific embodiment of the _{M 2} ×M ₁ convolution kernel unit shown in FIG. 5 ;

FIG. 8 is a schematic structural diagram of a second specific implementation manner of the optical signal processing module in FIG. 1;

FIG. 9 is a schematic structural diagram of the first specific embodiment of the optical nonlinear unit in FIG. 8;

Fig. 10 is the simulation result of the nonlinear function of light amplitude under different conditions when using the optical nonlinear unit shown in Fig. 9;

Fig. 11 is the simulation result of the nonlinear function of light intensity under different conditions when using the optical nonlinear unit shown in Fig. 9;

Fig. 12 is the structural schematic diagram of the third specific embodiment of the optical signal processing module in Fig. 1;

13 is a schematic structural diagram of a specific implementation manner of the light receiving module in FIG. 1;

FIG. 14 is a schematic structural diagram of the second specific embodiment of the optical nonlinear unit in FIG. 8;

Fig. 15 is the simulation result of the nonlinear function of light amplitude under different conditions when the optical nonlinear unit shown in Fig. 14 is used;

Fig. 16 is the simulation result of the nonlinear function of light intensity under different conditions when using the optical nonlinear unit shown in Fig. 14;

FIG. 17 is a schematic structural diagram of a second specific implementation manner of the minimum basic unit of the optical signal processing module in FIG. 1 .

detailed description

As mentioned in the background art, the computing power of existing photonic artificial intelligence chips is not satisfactory.

The inventors of the present application have found through analysis that this is because the existing photonic artificial intelligence chips perform linear operations on light of a single wavelength, or perform the same linear operations on lights of various wavelengths in the same optical signal, which leads to the failure of the photonic neural network. Computing power and flexibility are greatly limited.

To solve the above technical problem, an embodiment of the present invention provides a photonic neural network, including: an optical transmission module, the optical transmission module modulates the optical signal of the first array according to the signal to be processed, wherein the optical signal of the first array is Each beam of optical signal in the signal includes light of multiple wavelengths; an optical signal processing module is coupled to the light emission module to receive the optical signals of the first array, and the optical signal processing module at least Perform a linear operation on the optical signals of the array to obtain the optical signals of the second array, wherein, for each beam of optical signals in the optical signals of the first array, the optical signal processing module processes the optical signals of each wavelength in the optical signals. The linear operation of light is performed independently; the light receiving module is coupled to the optical signal processing module to receive the optical signals of the second array, and the light receiving module obtains and processes the optical signals based on the second array. Signal. Among them, the operation is independent of each other, which means that the parameters and/or operation algorithms used in the operation process are independent of each other and have no dependency relationship, and may be the same or different from each other, and may or may not be associated with each other.

The solution of this embodiment can greatly improve the computing power and flexibility of the photonic artificial intelligence chip. Specifically, the solution of this embodiment makes it possible to perform multi-core parallel processing of input light by independently performing linear operations on the light of each wavelength in the same optical signal, which is beneficial to improve the computing power and flexibility of the photonic artificial intelligence chip.

In order to make the above objects, features and beneficial effects of the present invention more clearly understood, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the principle of a photonic neural network according to an embodiment of the present invention.

The solution of this embodiment can be applied to application scenarios such as image recognition and speech recognition, and the photonic neural network 1 described in this embodiment can realize the recognition of images, speech, etc. with better computing power.

Specifically, referring to FIG. 1 , the photonic neural network 1 in this embodiment may include: an optical transmission module 11, which modulates the optical signal of the first array according to the signal to be processed (in the figure, 1, 2, ..., M ₁ mark), wherein each optical signal in the optical signals of the first array includes light of multiple wavelengths.

In a specific implementation, the signal to be processed may include a digital signal or an analog signal to be processed. For example, image signals for image recognition, voice signals for speech recognition. The light emitting module 11 encodes the digital signal or analog signal to be processed into an optical signal for subsequent operation.

For example, the photonic neural network 1 may receive, for example, a speech signal from a speaker, and process the received speech signal to recognize the content of the speech signal. Thus, speech recognition can be realized based on the photonic neural network 1 .

For another example, the photonic neural network 1 may receive, for example, an image signal from an image acquisition device, and process the received image signal to identify the content of the image signal. Thus, image recognition can be realized based on the photonic neural network 1 . Correspondingly, the to-be-processed signal may be the grayscale of multiple pixels of the image.

In a specific implementation, the transmission of optical signals between modules in the photonic neural network 1 described in this embodiment may be carried by a waveguide. Specifically, a waveguide refers to any structure capable of guiding an optical signal in any manner. Such as optical fibers, semiconductor waveguides fabricated in substrates, photonic crystal structures configured to guide optical signals, or any other suitable structure.

In a specific implementation, the signal to be processed may be input to the light emitting module 11 by other components, and the other components may be integrated within the photonic neural network 1 , or may be other components coupled to the photonic neural network 1 . connected external devices.

For example, the photonic neural network 1 may include an electrical control module 14 coupled with the light emitting module 11 to transmit the signal to be processed to the light emitting module 11 .

Specifically, the signal to be processed can be characterized as an electrical signal carrying corresponding information, and the electrical control module 14 transmits the electrical signal to the light emitting module 11 so that the light emitting module 11 can load the information in the electrical signal into the optical signal above to form the optical signals of the first array.

In a specific implementation, referring to FIG. 2 , the light emitting module 11 may include: an optical signal array generating unit 111, the optical signal array generating unit 111 is configured to generate an optical signal array, and each beam in the optical signal array The optical signal includes continuous light of multiple wavelengths, and the optical signal array generated by the optical signal array generating unit 111 is denoted as the optical signal of the third array; the modulator array 112 is coupled to the optical signal array generating unit 111 to Receiving the optical signals of the third array, the modulator array 112 is configured to apply a modulation signal to the optical signals of the third array to obtain the optical signals of the first array, wherein the modulation signal is the same as the optical signal of the third array. associated with the signal to be processed.

Specifically, in the figure, the optical signals of the third array and the optical signals of the first array are marked with 1, 2, . . . _{, M 1 .} The difference between the two is that the optical signal of the third array is the unmodulated original light output by the optical signal array generating unit 111 , while the optical signal of the first array is modulated by the modulator array 112 and carries the light to be processed. Light for signal related information.

Further, associating the modulated signal with the to-be-processed signal may refer to determining a specific value of the modulated signal according to specific information of the to-be-processed signal.

For example, after the optical signals of the third array pass through the modulator array 112, the intensity of the optical signals can be adjusted by the modulator array. According to different applied voltages, the intensity adjustment amount of each optical signal is different. The intensities of the input light and the output light are related, and through this relationship, the information of the signal to be processed can be loaded on the light.

In a specific implementation, the optical signals of the third array can be obtained by multiplexing laser arrays with different emission wavelengths through a wavelength multiplexer.

Specifically, continuing to refer to FIG. 2 , the optical signal array generating unit 111 may include a laser unit 113 for generating optical signals of multiple wavelengths (indicated by λ ₁ , λ ₂ , . . . , λ _{N in the figure).}

For example, the laser unit 113 may be implemented by a laser array with different emission wavelengths, and the laser array includes a plurality of lasers, wherein each laser outputs light of a specific wavelength respectively.

For another example, the laser unit 113 may include one or more multi-wavelength lasers, wherein each laser generates an optical signal of a specific wavelength or wavelengths.

Further, the optical signal array generating unit 111 may include a multiplexer 114, which is coupled to the laser unit 113 to wavelength-multiplex the optical signals of the multiple wavelengths into a continuous beam including multiple wavelengths.

For example, the multiplexer 114 may be an Arrayed Waveguide Grating (AWG for short) optical multiplexer.

Further, the optical signal array generating unit 111 may include a beam splitter 115 coupled to the multiplexer 114 . The beam splitter 115 may be a 1×M ₁ beam splitter, which is used to split the single beam optical signal including multiple wavelengths output by the multiplexer 114 into M ₁ beam optical signals. The optical signals of the third array obtained by splitting the beams are the optical signals of the third array, wherein each optical signal includes light of N wavelengths from _{λ 1} to λ _{N in total.}

For example, the beam splitter 115 may be a single beam splitting device.

For another example, the beam splitter 115 may be formed by cascaded multiple beam splitters.

In practical applications, the optical signal array generating unit 111 may adopt other similar structures to generate optical signals of a third array composed of M1 optical signals, wherein each optical signal includes a total of N wavelengths _{from λ 1} to λ _N of continuous light.

For example, the optical signal array generating unit 111 may be a multi-wavelength laser. The multi-wavelength laser directly emits a beam of continuous light containing multiple wavelengths, and then splits the beam by a beam splitter to obtain the optical signal of the third array. Signal.

In a specific implementation, the output optical signal of the light emitting module 11 (ie, the optical signal of the first array) may be an optical signal with multiple wavelengths and the same modulation signal. That is, the modulator array 112 applies the same modulation signal to the light of each wavelength of the same optical signal in the optical signals of the third array.

Further, the modulator array 112 may apply different modulation signals to different beams of optical signals in the optical signals of the third array.

For example, the modulator array 112 may include M1 modulators, where each modulator is used to modulate one optical signal. Specifically, each modulator loads the same optical signal, but each modulator applies different voltages to the optical signal, thereby obtaining modulation results of different intensities. Therefore, in the optical signals of the first array output by the modulator array 112, the information to be processed carried by each wavelength in the same optical signal is the same, and the information carried by the same wavelength in different optical signals may be different.

Of course, the modulator array 112 can apply the same modulation signal to some of the optical signals in the beams, and the information carried by the same wavelength in the optical signals in the different beams can also be the same.

In a specific implementation, the modulator array 112 may apply different modulation signals to light of different wavelengths of the same optical signal in the optical signals of the third array. Therefore, the output optical signal of the light emitting module 11 may be an optical signal with various wavelengths and different modulation signals.

For example, for the same beam of optical signal, the corresponding modulator loads different voltages for different wavelengths of the beam of light, so as to obtain modulation results of different intensities.

In a specific implementation, the modulator array 112 may employ electro-optic, acousto-optic, thermo-optic and other types of modulators.

In a specific implementation, FIG. 3 shows a schematic structural diagram of a specific implementation manner of a single modulator in the modulator array 112 . The modulator array 112 may include M ₁ modulators shown in FIG. 3 . The modulator may be referred to as a multi-wavelength optical modulator unit 116 to realize modulation of optical signals of different wavelengths.

The plurality of multi-wavelength light modulator units 116 are in one-to-one correspondence with the optical signals of the third array, wherein each multi-wavelength light modulator unit 116 is used for a certain beam of optical signals in the optical signals of the third array to modulate.

Specifically, referring to FIG. 3 , the multi-wavelength optical modulator unit 116 may include an input waveguide, an optical interference unit 117 and an output waveguide.

The received optical signal input waveguide may be a plurality of continuous light of a wavelength _{(λ 1, λ 2, ...} , λ N), i.e., a single beam optical signal of the optical signal in the third array.

Further, the optical interference unit 117 may be a 1×1 Mach-Zehnder interferometer. The 1×1 Mach-Zehnder interferometer may include two 1×2 beam splitters (identified as beam splitter 1 and beam splitter 2 in the figure, respectively) and two wavelength-sensitive phase shifter arrays 118 . Among them, the wavelength-sensitive phase shifter array may also be referred to as a wavelength-dependent phase shifter array.

For example, the beam splitter may use a directional coupler (Directional Coupler, DC for short), a multi-mode interferometer (Multi-Mode Interferometer, MMI for short), and the like.

Further, two wavelength-sensitive phase shifter arrays 118 can be disposed on the upper arm and the lower arm of the 1×1 Mach-Zehnder interferometer, respectively, to independently modulate the light of each wavelength in the input optical signal.

For example, the wavelength sensitive phase shifter array 118 may perform independent phase shifting operations on optical signals of a single wavelength.

Further, the wavelength-sensitive phase shifter array 118 can be implemented by wavelength-dependent devices such as microring resonators, gratings, and the like. Phase shifting can be achieved by means of thermo-optic, electro-optic, phase transition, plasma dispersion, etc. Fig. 3 exemplifies the micro-ring resonator as an example.

Further, the wavelength-sensitive phase shifter array 118 may include a plurality of phase shifters (marked by a circle in the figure), and the plurality of phase shifters correspond to the light of each wavelength in the input optical signal one-to-one . That is, a single wavelength-sensitive phase shifter array 118 includes the number of phase shifters corresponding to the number of wavelengths of the input light, and performs phase shifting operations on the input continuous light containing multiple wavelengths in parallel with multiple cores.

Further, the sum of the phase shift parameters of the phase shifters corresponding to the same wavelength in the wavelength-sensitive phase shifter array 118 arranged on the upper arm and the wavelength-sensitive phase shifter array 118 arranged on the lower arm is an integer of 2π times. Thereby, the introduction of phase deviation can be avoided and pure intensity modulation can be achieved.

Assuming that the micro-ring phase shifter with the resonance wavelength of the upper arm of the phase shifter is λ _m , the corresponding phase-shifting parameter is θ _λm-U ; the micro-ring phase shifter whose lower arm resonant wavelength is λ _{m, the corresponding phase-shifting parameter} is θ _λm-D . Then, when the optical interference unit 117 modulates the input optical signal, let θ _λm-U + θ _λm-D =2kπ, where k is an integer.

Correspondingly, for an optical signal with a wavelength of λ _m , the transmission matrix of the optical interference unit 117

It can be described as formula (1):

where the transfer matrix

Used to describe the variation of the complex amplitude of an optical signal.

Thus, independent phase shifting operations for optical signals of different wavelengths in the same beam of optical signals are realized based on the wavelength-sensitive phase shifter array 118.

In a specific implementation, the optical transmitting module 11 can adopt the structure shown in FIG. 4 , the light of each wavelength is divided into M1 optical signals and modulated respectively and output to the corresponding multiplexer, and the multiplexer combines the lights of different wavelengths into M1 beams of optical signals. In the same waveguide, the optical signals of the first array are finally formed.

In the optical signal of the first array generated by the structure shown in FIG. 4 , the information carried by each wavelength in the same optical signal is different. That is, the optical signals of the first array generated by the structure shown in FIG. 4 may be optical signals with various wavelengths and different modulation signals. Of course, in the optical signals of the first array generated by the structure shown in FIG. 4 , the information carried by each wavelength in the same optical signal can also be the same. As long as the signals to be processed applied by the modulator are the same, then each wavelength carries the same information. information can be considered to be the same.

Specifically, referring to FIG. 4 , the light emitting module 11 may include a laser unit 113 for generating light of N wavelengths. For the specific structure of the laser unit 113 , reference may be made to the related description of the embodiment shown in FIG. 2 , which will not be repeated here. When the laser unit 113 includes one or more multi-wavelength lasers, the optical signals output by the laser unit 113 need to be separated by a wavelength demultiplexer to separate optical signals of different wavelengths, and then output to subsequent modules.

Further, the light emitting module 11 may include N 1×M ₁ beam splitters (indicated by beam splitter 1 to beam splitter N in the figure), the N 1×M ₁ beam splitters and the N 1×M 1 beam splitters The wavelengths are in one-to-one correspondence, and are used to split the received single-wavelength optical signal into M ₁ single-wavelength optical signals.

Further, the light emitting module 11 may include N modulator arrays (indicated by modulator array 1 to modulator array N in the figure), and the N modulator arrays correspond to the N beam splitters one-to-one, It is used to modulate the optical signal of a single wavelength of the _{received M 1 beam.}

For any one of the N modulator arrays, the modulator array may include M ₁ optical modulators, which may be electro-optic, acousto-optic, thermo-optic and other modulators. For the specific structure of the modulator array, reference may be made to the related description in FIG. 2 .

For any one of the N modulator arrays, the modulator array can _{apply different modulation signals to the input M 1} beams of optical signals of a single wavelength.

Further, the optical transmission module 11 may include M ₁ wavelength division multiplexers (identified by multiplexer 1 to multiplexer M _{1 in the} figure), wherein each wavelength division multiplexer is used to combine the N modulator arrays One channel of modulated optical signals outputted by each is wavelength-division multiplexed into one channel of optical signals. The outputs of the M ₁ wavelength division multiplexers are the optical signals of the first array.

_{Taking an optical signal with a wavelength of λ m} output by the laser unit 113 as an example, the optical signal is first divided into M ₁ beams _{equally by a 1×M 1 beam splitter m.} The M ₁ beams of light are respectively modulated by the corresponding modulators in the modulator array m, and then respectively connected to the M ₁ wavelength division multiplexers.

Correspondingly, for each wavelength division multiplexer, the optical signals of different wavelengths received by the wavelength division multiplexer are modulated by different modulator arrays, and thus, the optical transmission module 11 can Different wavelengths of light can be modulated differently.

Alternatively, the M ₁ wavelength division multiplexers may perform wavelength division multiplexing on light of different wavelengths modulated by applying the same modulation signal to each modulator array, so as to obtain a single beam in the optical signal of the first array by compounding optical signal. Therefore, the light emitting module 11 using the structure shown in FIG. 4 can output a plurality of optical signals with the same wavelength modulation.

In the light emitting module 11 shown in FIG. 4 , the optical signal array generating unit 111 can be equivalent to the remaining modules except the modulator arrays 1 to N. The difference from the optical signal array generating unit 111 shown in FIG. 2 is that this implementation For example, the optical signal array generating unit 111 modulates the light of each wavelength individually, and only combines them into an optical signal at the end.

From the above, the optical signals of the first array output by the light emitting module 11 may be optical signals with different wavelengths and the same modulation signal, or may be optical signals with different wavelengths but different modulation signals.

In a specific implementation, continuing to refer to FIG. 1 , the photonic neural network 1 may further include an optical signal processing module 12 coupled to the optical transmission module 11 to receive the optical signals of the first array, the optical signals The processing module 12 at least performs linear operations on the optical signals of the first array to obtain the optical signals of the second array (indicated by 1, 2, . . . , M _{2 in the} figure), wherein, for the first array of For each optical signal in the optical signal, the optical signal processing module 12 performs the linear operation on the light of each wavelength in the optical signal independently.

Specifically, for each beam of optical signals in the first array of optical signals, the optical signal processing module 12 performs linear operations on the light of each wavelength in the optical signal independently, which may refer to : The optical signal processing module 12 respectively configures corresponding convolution kernels for light of different wavelengths in the optical signal, and the linear operations of each convolution kernel for the light of corresponding wavelengths are independent of each other.

Therefore, by independently setting up a convolution kernel for each wavelength, the calculation results of each wavelength do not affect each other. Further, the solution of this embodiment provides a multi-core parallel operation photonic neural network 1, which performs linear operations on the light of multiple wavelengths in the optical signal in parallel through multiple convolution cores, which greatly improves the overall operation speed and calculation speed. force.

In a specific implementation, referring to FIG. 5 , the optical signal processing module 12 may include a linear matrix multiplication unit 121 for performing a multi-core parallel matrix multiplication operation on each optical signal in the optical signal of the first array, to obtain the optical signals of the second array.

In this embodiment, the number of the linear matrix multiplying units 121 may be one.

Specifically, the linear matrix multiplying unit 121 may include an input waveguide array, an M ₂ ×M ₁ convolution kernel unit 122 and an output waveguide array. Wherein, the input waveguide array is adapted to receive the optical signals of the first array, and the output waveguide array is adapted to output the optical signals of the second array.

In a specific implementation, referring to FIG. 6 , the M ₂ ×M ₁ convolution kernel unit 122 in the linear matrix multiplication unit 121 may include: a plurality of optical interference units 123 connected in series and parallel to each other, wherein each optical interference unit 123 The interference arms of the optical interference unit 123 are provided with a wavelength-sensitive phase shifter array 124, and at least one of the input arm and the output arm of each optical interference unit 123 is provided with the wavelength-sensitive phase shifter array 124, so as to adjust the input of the optical The light of each wavelength in the optical signal of the interference unit 123 performs an independent phase shift operation.

Specifically, the optical interference unit 123 can be used as the minimum basic unit of the _{M 2} ×M _{1 convolution kernel unit 122 .} The M ₂ ×M ₁ convolution kernel unit 122 may be composed of the optical interference unit 123 shown in FIG. 6 in a certain connection manner.

FIG. 7 exemplarily shows a 4×4 convolution kernel unit, wherein In1 to In4 are the optical signals of the first array, and Out1 to Out4 are the optical signals of the second array. V ^T is a unitary matrix, ∑ is a diagonal matrix, and U is a unitary matrix. It should be pointed out that the _{specific connection mode of each optical interference unit 123 in the M 2} ×M ₁ convolution kernel unit 122 can be adjusted according to actual needs, which is not limited here.

5 to 7 , the optical interference unit 123 may be a 2×2 Mach-Zehnder interferometer provided with a wavelength-sensitive phase shifter array 124 for the input arm (or output arm) and the interference arm. The 2×2 Mach-Zehnder interferometer may include two 2×2 beam splitters 125 , and the arm between the two 2×2 beam splitters 125 is an interference arm, located in the first 2×2 beam splitter The arm to the left of the second 2x2 beamsplitter 125 is the input arm, and the arm to the right of the second 2x2 beamsplitter 125 is the output arm. The wavelength-sensitive phase shifter array 124 is exemplarily shown in the figure using a micro-ring resonator phase shifter as an example.

Further, the wavelength-sensitive phase shifter array 124 may include a plurality of phase shifters (an example is a circle in the figure), and the plurality of phase shifters correspond to each wavelength of light in the input optical signal one-to-one. That is, the interference arm and the input arm of the optical interference unit 123 constituting the most basic unit of the optical signal processing module 12 are provided with an optically sensitive phase shifter array 124 composed of a plurality of phase shifters. The number of phasers corresponds to the number of wavelengths of the input light, so as to realize multi-core parallel processing of the input light.

FIG. 6 exemplarily shows as an example that both the interference arm of the optical interference unit 123 and the upper arm of the input arm are provided with the wavelength-sensitive phase shifter array 124 . In practical applications, the wavelength-sensitive phase shifter array 124 may also be provided in the interference arm and the output arm, or the wavelength-sensitive phase shifter array 124 may be provided in the interference arm, the input arm and the output arm. In practical applications, the wavelength-sensitive phase shifter array 124 located on the interference arm can be arranged on the upper arm of the interference arm, and the wavelength-sensitive phase shifter array 124 located on the input arm can be arranged on the input arm Alternatively, the wavelength-sensitive phase shifter array 124 located in the interference arm can be located in the lower arm of the interference arm, and the wavelength-sensitive phase shifter array 124 located in the input arm can be located in the input arm. Alternatively, the wavelength-sensitive phase shifter array 124 located on the interference arm can be located on the upper arm of the interference arm, and the wavelength-sensitive phase shifter array 124 located on the input arm can be located on the upper arm of the interference arm. the lower arm of the input arm; alternatively, the wavelength-sensitive phase shifter array 124 located on the interference arm may be disposed on the lower arm of the interference arm, and the wavelength-sensitive phase shifter array 124 located on the input arm may Installed on the upper arm of the input arm.

For example, each phase shifter in the optically sensitive phase shifter array 124 performs a phase shifting operation for light of a corresponding wavelength, respectively.

Further, the 2×2 Mach-Zehnder interferometer shown in FIG. 6 can be represented by a 2×2 transmission matrix, as shown in formula (2):

in,

is the transmission matrix for light with wavelength λ _m,

and θ _λm are the phase shifter parameters _{for the wavelength λ m} in the 2×2 Mach-Zehnder interferometer.

From the above, the optical interference unit 123 provided with the optically sensitive phase shifter array 124 can realize independent matrix multiplication operations for light of different wavelengths. Taking the basic unit of the convolution kernel shown in FIG. 6 as an example, the matrix multiplication operation of the optical signals of N wavelengths can be realized at the same time.

In a specific implementation, the optical signal processing module 12 may include a plurality of cascaded linear matrix multiplication units 121 , wherein the output of the linear matrix multiplication unit 121 of the previous stage is the linear matrix of the subsequent stage The input of the multiplication unit 121, the input of the linear matrix multiplication unit 121 of the first stage is the optical signal of the first array, and the output of the linear matrix multiplication unit 121 of the last stage is the optical signal of the second array.

In a specific implementation, the optical signal processing module 12 may further include: an optical nonlinear unit 126, coupled to the linear matrix multiplying unit 122 to receive the optical signal of the first array by the linear matrix multiplying unit 122 The linear operation result of the signal is performed, and a nonlinear operation is performed on the linear operation result of the optical signal of the first array according to the optical signal of the reference array to obtain the optical signal of the second array.

Specifically, referring to FIG. 8 , the optical signal processing module 12 may be a cascaded structure of a linear matrix multiplication unit 122 and an optical nonlinear unit 126 .

The specific structure of the linear matrix multiplying unit 122 may refer to the minimum basic unit structure shown in FIG. 6 .

In a specific implementation, the linear operation result of the optical signals of the first array is denoted as the optical signals of the fourth array, and the optical nonlinear unit 126 is responsible for the light of each wavelength in the optical signals of the fourth array. Non-linear operations are performed independently. That is, the optical nonlinear unit 126 can perform independent nonlinear operations on light of a single wavelength.

Specifically, referring to FIG. 9 , the optical nonlinear unit 126 may include: a plurality of optical interference units 127 , wherein each optical interference unit 127 respectively receives the optical signal of the fourth array and the optical signal of the reference array, so The input arm and the interference arm of the optical interference unit 127 are provided with a wavelength-sensitive phase shifter array 124, so as to perform independent nonlinear nonlinearity on the light of each wavelength in the optical signal of the fourth array according to the optical signal of the reference array. Transform operation.

FIG. 9 exemplarily shows an example that the upper arm of the input arm receives the optical signal of the fourth array, and the lower arm of the input arm receives the optical signal of the reference array. In practical applications, the lower arm of the input arm may also receive the optical signal of the fourth array, and the upper arm of the input arm may receive the optical signal of the reference array. Further, the wavelength sensitive phase shifter array 124 disposed in the interference arm and the wavelength sensitive phase shifter array 124 disposed in the input arm may be on the same side, eg, both on the upper arm or both on the lower arm. Alternatively, the wavelength-sensitive phase shifter array 124 provided on the interference arm and the wavelength-sensitive phase shifter array 124 provided on the input arm may be on opposite sides, for example, the upper arm of the input arm is provided with the wavelength-sensitive phase shifter array 124 , and the lower arm of the interference arm is provided with a wavelength-sensitive phase shifter array 124 .

A plurality of the optical interference units 127 are in one-to-one correspondence with the optical signals of the fourth array, wherein each optical interference unit 127 is used to perform an independent nonlinear transformation operation on each wavelength in a beam of light. Further, the nonlinear change operation of each optical interference unit 127 on the light of the corresponding wavelength is not affected by other optical interference units.

Further, the optical interference unit 127 may be a 2×2 Mach-Zehnder interferometer provided with a wavelength-sensitive phase shifter array 124 on the upper arm. The 2×2 Mach-Zehnder interferometer may include two 2×2 beam splitters 125 , and the input end of the first 2×2 beam splitter 125 in the two 2×2 beam splitters 125 is the The input arm of the optical interference unit 127, the upper arm of which is provided with an optically sensitive phase shifter array 124 and used to receive the optical signals of the fourth array. The lower arm of the input arm is not provided with an optically sensitive phase shifter array 124 and is used to receive the optical signal of the reference array. The wavelength-sensitive phase shifter array 124 is exemplarily shown in the figure using a micro-ring resonator phase shifter as an example.

Further, the wavelength-sensitive phase shifter array 124 may include a plurality of phase shifters (an example is a circle in the figure), and the plurality of phase shifters correspond to each wavelength of light in the input optical signal one-to-one. For example, each phase shifter in the optically sensitive phase shifter array 124 performs a phase shifting operation for light of a corresponding wavelength, respectively.

The difference between the optical interference unit 127 shown in FIG. 9 and the optical interference unit 123 shown in FIG. 6 is that the lower arm of the input arm of the 2×2 Mach-Zehnder interferometer shown in FIG. 9 is adapted to receive the optical signal of the reference array. Therefore, among the two wavelength-sensitive phase shifter arrays 124 included in the optical interference unit 127 , the wavelength-sensitive phase shifter array 124 located in the input arm can be used to adjust the phase difference between the signal light and the reference light.

Continuing to refer to FIG. 9 , the optical signal E _in (λ _m ) of the fourth array and the optical signal E _ref (λ _m ) of the reference array are simultaneously input to the 2×2 Mach-Zehnder interferometer, and the output can be described as the formula (3) shows:

in,

is the phase difference between the optical signal of the fourth array and the optical signal of the reference array; both E _out1 (λ _m ) and E _out2 (λ _m ) can be used as outputs of a 2×2 Mach-Zehnder interferometer.

Specifically, the optical signal of the reference array and the optical signal of the fourth array come from the same laser, and are not intensity modulated by a modulator, and are continuous light.

For example, the optical signal of the reference array may be the unmodulated optical signal of the third array output by the optical signal array generating unit 111 .

Taking E _out1 (λ _m ) as an example, its intensity O ₁ (λ _m ) can be described as shown in formula (4):

Wherein I _in (λ _m ) is the light intensity of the optical signal of the fourth array, and I _ref (λ _m ) is the light intensity of the optical signal of the reference array.

The all-optical nonlinear activation function structure formed by the optical interference unit 127 provided in this example can realize nonlinear transformation of light amplitude, and can also realize nonlinear transformation of light intensity. By adjusting the phase shifter parameters of the 2×2 Mach-Zehnder interferometer

and θ _{λm and the light intensity I ref} (λ _m ) of the optical signal of the reference array, different nonlinear activation functions can be realized.

In a typical application scenario, see Fig. 10, Fig. 10 shows different phase shifter parameters when the structure shown in Fig. 9 is adopted

and θ _λm and the nonlinear transformation curve _{of the light intensity I ref} (λ _m ) of the optical signal of the reference array to the optical amplitude. in,

I _ref = 53uW,

In Fig. 10, the solid line corresponds to the phase shifter parameter θ _λm =0.534π, the dotted line corresponds to the phase shifter parameter θ _λm =0.789π, the dotted line corresponds to the phase shifter parameter θ _λm =0.985π, the solid line and the circle mark correspond to the phase shifter parameter θ λm =0.985π The phase shifter parameter θ _λm =1.294π; the dotted line and the circle mark correspond to the phase shifter parameter θ _λm =1.454π.

In a typical application scenario, see Figure 11, which shows different phase shifter parameters when the structure shown in Figure 9 is used

and θ _λm and the nonlinear transformation curve _{of the light intensity I ref} (λ _m ) of the optical signal of the reference array to the light intensity. Wherein, I _ref (λ _m )=53uW,

The solid line in Fig. 11 corresponds to θ _λm =0.534π,

The dotted line corresponds to θ _λm = 0.789π,

The dot-dash line corresponds to θ _λm =1.294π,

In a variation example, on the input arm side, the specific setting position of the optically sensitive phase shifter array 124 can be set at the position of the optical interference unit 127 for receiving the optical signal of the reference array, in addition to the embodiment shown in FIG. 9 . input arm. That is, both the upper and lower arms of the input arm may be provided with an optically sensitive phase shifter array 124, with either of the upper and lower arms receiving the optical signal of the reference array and the other receiving the optical signal of the fourth array Signal.

Alternatively, on the input arm side, an optically sensitive phase shifter array 124 may be provided only on the arm that receives the optical signal of the reference array.

In a modified example, on the side of the interference arm, the specific arrangement position of the optically sensitive phase shifter array 124 may be arranged on the lower arm of the interference arm, in addition to the embodiment shown in FIG. 9 . That is, both the upper and lower arms of the interference arm may be provided with an optically sensitive phase shifter array 124 .

Alternatively, on the side of the interference arm, the optically sensitive phase shifter array 124 may be provided only on the lower arm.

In a specific implementation, referring to FIG. 8 and FIG. 12 , the coupled linear matrix multiplication unit 122 and the optical nonlinear unit 126 are denoted as a neural network unit 128 , and the optical signal processing module 12 may include multiple The neural network units 128 are cascaded, wherein the output of the neural network unit 128 of the previous stage is the input of the neural network unit 128 of the next stage, and the input of the neural network unit 128 of the first stage is the optical fiber of the first array. signal, the output of the last stage neural network unit 128 is the optical signal of the second array.

That is, the optical signal processing module 12 may be formed by a combination of multiple linear matrix multiplying units 122 and optical nonlinear units 126 in cascade.

FIG. 12 takes L neural network units 128 as an example for exemplary illustration, wherein the input of the first-stage neural network unit 128 is the optical signal of the first array, and the output of the L-th neural network unit 128 is the optical signal of the second array. Signal.

Further, the output numbers of the linear matrix multiplication units 122 of at least some of the neural network units 128 in the L neural network units 128 may be different from the output numbers of the linear matrix multiplication units 122 of other neural network units 128 .

For example, the linear matrix multiplication unit 122 of the first-stage neural network unit 128 may include M ₂ ×M ₁ convolution kernels, and the linear matrix multiplication unit 122 of the second-stage neural network unit 128 may include M ₃ ×M ₂ convolution kernels, ..., the linear matrix multiplication unit 122 of the L-th level neural network unit 128 may include a _ML+1 × _ML convolution kernel. Wherein, M ₁ , M ₂ , M ₃ , . . . , _ML and _ML+1 may be completely equal, partially equal or unequal to each other.

In a specific implementation, continuing to refer to FIG. 1 , the photonic neural network 1 may further include: a light receiving module 13 coupled to the optical signal processing module 12 to receive the optical signals of the second array, the light The receiving module 13 may acquire the processed signal based on the optical signals of the second array.

Specifically, referring to FIG. 13 , the light receiving module 13 may include M ₂ demultiplexers 131 and M ₂ photodetector arrays 132 . Each optical signal in the second array of optical signals is input to the corresponding demultiplexer 131 . After being demultiplexed by the corresponding demultiplexer 131, light of N wavelengths (λ ₁ , λ ₂ , . . . , λ _{N ) can be obtained.}

The M ₂ photodetector arrays 132 are in one-to-one correspondence _{with the M 2 demultiplexers 131 .} For each of the photodetector arrays 132 , the photodetector arrays 132 include N detectors to perform photoelectric conversion on the N wavelengths of light obtained by demultiplexing, respectively, to obtain electrical signals. The electrical signal is the processed signal.

In a specific implementation, the processed signal is transmitted to the electrical control module 14 through a circuit.

The electrical control module 14 may receive and condition the processed signal. For example, an operation such as amplifying the processed signal is performed.

In a specific implementation, the electrical control module 14 can also control the parameters in the modulator array 112 and the optical signal processing module 12 .

In a specific implementation, when the optical signal processing module 12 only includes the linear matrix multiplication unit 122, the electrical control module 14 is further configured to perform a nonlinear transformation operation on the received processed signal in the electrical domain .

In a specific implementation, the electrical control module 14 may also be coupled with the light emitting module 11 to transmit the adjusted processed signal to the light emitting module 11 as a signal to be processed, so as to perform another One round of linear transformation. Thus, iterative deep learning can be realized.

In a specific implementation, the electrical control module 14 may transmit the received processed signals to the input waveguides of other photonic computing structures to perform another round of linear transformation.

In a variation of this embodiment, the specific structure of the optical interference unit 127 may be as shown in FIG. 14 . Specifically, the difference from the structure shown in FIG. 9 is that the optical interference unit 127 shown in FIG. 14 only includes one 2×2 beam splitter 125 , and the number of wavelength-sensitive phase shifter arrays 124 is also one and located at the input arm to adjust the phase difference between the signal light and the reference light. The optical interference unit 127 shown in FIG. 14 can also implement an all-optical nonlinear activation function.

Continuing to refer to FIG. 14 , the optical signal E _in (λ _m ) of the fourth array and the optical signal E _ref (λ _m ) of the reference array are simultaneously input to the 2×2 beam splitter 125 , and the 2×2 beam splits The device 125 may use a directional coupler (Directional Coupler, DC for short), a multi-mode interferometer (Multi-Mode Interferometer, MMI for short), and the like. The output of the optical interference unit 127 can be described as shown in formula (5):

in,

is the phase difference between the optical signal of the fourth array and the optical signal of the reference array; both E _out1 (λ _m ) and E _out2 (λ _m ) can be used as the output of the 2×2 beam splitter 125 .

Specifically, the optical signal of the reference array and the optical signal of the fourth array come from the same laser, and are not intensity modulated by a modulator, and are continuous light.

For example, the optical signal of the reference array may be the unmodulated optical signal of the third array output by the optical signal array generating unit 111 .

Taking E _out1 (λ _m ) as an example, its intensity O ₁ (λ _m ) can be described as shown in formula (6):

Wherein, I _in (λ _m ) is the light intensity of the optical signal of the fourth array; I _ref (λ _m ) is the light intensity of the optical signal of the reference array; * represents the complex conjugate;

The all-optical nonlinear activation function structure formed by the optical interference unit 127 provided in this example can realize nonlinear transformation of light amplitude, and can also realize nonlinear transformation of light intensity. By adjusting the phase shifter parameters of the 2×2 beam splitter

_{and the optical intensities I ref} (λ _m ) of the optical signal of the reference array, different nonlinear activation functions can be realized.

In the application scenario where the optical interference unit 127 shown in FIG. 14 is used to form the optical nonlinear unit 126, see FIG. 15, which shows different phase shifter parameters

and the nonlinear transformation curve of the optical signal of the reference array to the optical amplitude under the condition of _{I ref} (λ _{m ).} in,

The solid line in Figure 15 corresponds to the phase shifter parameters

The dotted line corresponds to the phase shifter parameters

The dot-dash line corresponds to the phase shifter parameters

The solid line and the circle mark correspond to the phase shifter parameters

The dotted line and the circle mark correspond to the phase shifter parameters

In the application scenario where the optical interference unit 127 shown in FIG. 14 is used to form the optical nonlinear unit 126, see FIG. 16, which shows different phase shifter parameters

and the nonlinear transformation curve _{of the light intensity I ref} (λ _m ) of the optical signal of the reference array to the light intensity. in,

The solid line in Figure 16 corresponds to

I _ref (λ _m )=53uW; the dotted line corresponds to

I _ref (λ _m )=10uW; dotted line corresponds to

I _ref (λ _m )=5uW.

In a variation example, on the input arm side, the specific setting position of the optically sensitive phase shifter array 124 can be set at the position of the optical interference unit 127 for receiving the optical signal of the reference array, in addition to the embodiment shown in FIG. 14 . input arm. That is, both the upper and lower arms of the input arm may be provided with an optically sensitive phase shifter array 124, with either of the upper and lower arms receiving the optical signal of the reference array and the other receiving the optical signal of the fourth array Signal.

Alternatively, on the input arm side, an optically sensitive phase shifter array 124 may be provided only on the arm that receives the optical signal of the reference array.

In a variation of this embodiment, the structure of the optical interference unit 123 in the linear matrix multiplying unit 121 may be as shown in FIG. 17 . The difference from the structure shown in FIG. 6 is that the optical interference unit 123 shown in FIG. 17 _{An N 1} x N ₃ Mach-Zehnder interferometer with wavelength sensitive phase shifter array 124 may be provided for the input arm (or output arm) as well as the interference arm.

The N ₁ ×N ₃ Mach-Zehnder interferometer may include two beam splitters 125 , wherein the beam splitter 125 (identified as beam splitter 1 in the figure) between the input arm and the interference arm is N ₁ ×N ₂ beam splitters, the beam splitter 125 (identified as beam splitter 2 in the figure) located between the interference arm and the output arm is an N ₂ ×N ₃ beam splitter. Wherein, N ₁ , N ₂ and N ₃ are all integers greater than or equal to 2 _{, and the specific numerical values of N 1} , N ₂ and N ₃ may be completely the same, partially the same or completely different.

_{For the N 1} arms included in the input arm, N ₁ −1 arms may be respectively provided with the wavelength-sensitive phase shifter array 124 .

_{For the N 2} arms included in the interference arm, N ₂ −1 arms may be respectively provided with the wavelength-sensitive phase shifter array 124 .

For the specific structure of the wavelength-sensitive phase shifter array 124, reference may be made to the relevant description in the embodiment shown in FIG. 6 .

The photonic neural network 1 in this embodiment can be used in application fields such as image processing, image recognition, speech recognition, gene sequencing, quantum communication or quantum computing.

From the above, the solution of this embodiment can greatly improve the computing power and flexibility of the photonic artificial intelligence chip. Specifically, the solution of this embodiment makes it possible to perform multi-core parallel processing on the input light by independently performing linear operations on the light of each wavelength in the same optical signal, which is beneficial to improve the computing power and flexibility of the photonic artificial intelligence chip. Further, it can also improve the computing power of photonic artificial intelligence chips per unit area.

Further, the photonic neural network 1 in this embodiment can implement different matrix multiplication operations and nonlinear operations for the same modulation signal, and can also implement different matrix multiplication operations and nonlinear operations for different modulation signals.

The advantages of the present invention are: firstly, a single optical structure can be used to realize the parallel operation of different matrix multiplication operations and nonlinear operations for the same modulation signal, which greatly improves the computing power of the photonic neural network chip and the computing power per unit area; secondly, it can Using a single optical structure to realize the parallel operation of different matrix multiplication operations and nonlinear operations for different modulation signals can realize the parallel operation of a single task or the parallel operation of different tasks, which greatly improves the computing power and unit area of the photonic neural network chip. computing power, and flexibility.

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be based on the scope defined by the claims.

Claims (20)

1. A photonic neural network, comprising:

   an optical emission module, which modulates the optical signals of the first array according to the signal to be processed, wherein each optical signal in the optical signals of the first array includes light of multiple wavelengths;

   an optical signal processing module, coupled to the optical transmission module to receive the optical signals of the first array, the optical signal processing module at least performs linear operations on the optical signals of the first array to obtain the optical signals of the second array signal, wherein, for each optical signal in the optical signals of the first array, the optical signal processing module performs the linear operation on the light of each wavelength in the optical signal independently;

   an optical receiving module coupled to the optical signal processing module to receive the optical signals of the second array, and the optical receiving module obtains the processed signals based on the optical signals of the second array.
2. The photonic neural network according to claim 1, wherein, for each optical signal in the optical signals of the first array, the optical signal processing module processes the light of each wavelength in the optical signal. The linear operations of are performed independently, meaning:

   The optical signal processing module configures corresponding convolution kernels respectively for light of different wavelengths in the optical signal, and the linear operations of the respective convolution kernels for the light of respective corresponding wavelengths are independent of each other.
3. The photonic neural network according to claim 1, wherein the optical signal processing module comprises:

   A linear matrix multiplication unit, configured to perform a multi-core parallel matrix multiplication operation on each optical signal in the optical signals of the first array to obtain the optical signals of the second array.
4. The photonic neural network according to claim 3, wherein the linear matrix multiplication unit comprises:

   A plurality of optical interference units connected in series and parallel to each other, wherein the interference arm of each optical interference unit is provided with a wavelength-sensitive phase shifter array, and at least one of the input arm and the output arm of each optical interference unit is provided with the wavelength A sensitive phase shifter array is used to perform independent phase shifting operations on the light of each wavelength in the optical signal input to the optical interference unit.
5. The photonic neural network according to claim 3, wherein the optical signal processing module comprises a plurality of cascaded linear matrix multiplication units, wherein the output of the linear matrix multiplication unit of the previous stage is the output of the linear matrix multiplication unit of the previous stage. The input of the linear matrix multiplying unit of the first stage is the optical signal of the first array, and the output of the linear matrix multiplying unit of the last stage is the optical signal of the second array. Signal.
6. The photonic neural network according to claim 3, wherein the optical signal processing module further comprises:

   an optical nonlinear unit, coupled to the linear matrix multiplying unit to receive a linear operation result of the linear matrix multiplying unit on the optical signals of the first array, and to perform linear operations on the optical signals of the first array according to the optical signals of the reference array A nonlinear operation is performed on the linear operation result of the optical signal to obtain the optical signal of the second array.
7. The photonic neural network according to claim 6, wherein the coupled linear matrix multiplication unit and the optical nonlinear unit are denoted as a neural network unit, and the optical signal processing module comprises a plurality of cascaded The neural network unit, wherein the output of the previous neural network unit is the input of the subsequent neural network unit, the input of the first neural network unit is the optical signal of the first array, and the final neural network The output of the cell is the optical signal of the second array.
8. The photonic neural network according to claim 6, wherein the linear operation result of the optical signals of the first array is denoted as the optical signals of the fourth array, and the optical nonlinear unit has no effect on the optical signals of the fourth array. The nonlinear operation of each wavelength of light in the optical signal is performed independently.
9. The photonic neural network according to claim 8, wherein the optical nonlinear unit comprises:

   a plurality of optical interference units, wherein each optical interference unit receives the optical signal of the fourth array and the optical signal of the reference array respectively, the input arm and the interference arm of the optical interference unit are provided with a wavelength-sensitive phase shifter array, An independent nonlinear transformation operation is performed on the light of each wavelength in the optical signal of the fourth array according to the optical signal of the reference array.
10. The photonic neural network according to claim 8, wherein the optical nonlinear unit comprises:

    a plurality of optical interference units, wherein each optical interference unit receives the optical signal of the fourth array and the optical signal of the reference array respectively, the input arm of the optical interference unit is provided with a wavelength-sensitive phase shifter array to The optical signal of the reference array performs an independent nonlinear transformation operation on the light of each wavelength in the optical signal of the fourth array.
11. The photonic neural network according to claim 4, 9 or 10, wherein the wavelength-sensitive phase shifter array comprises a plurality of phase shifters, and the plurality of phase shifters are associated with each wavelength in the input optical signal. light one-to-one correspondence.
12. The photonic neural network according to any one of claims 1 to 10, wherein the light emission module comprises:

    an optical signal array generating unit, the optical signal array generating unit is used to generate an optical signal array, and each optical signal in the optical signal array includes continuous light of multiple wavelengths, and the optical signal array generating unit generates The optical signal array of is recorded as the optical signal of the third array;

    a modulator array, coupled with the optical signal array generating unit to receive the optical signals of the third array, the modulator array is used for applying modulation signals to the optical signals of the third array to obtain the third array An array of optical signals, wherein the modulated signal is associated with the signal to be processed.
13. The photonic neural network according to claim 12, wherein the modulator array applies the same modulation signal to the light of each wavelength of the same optical signal in the optical signals of the third array, and applies the same modulation signal to the third array of optical signals. Different beams of optical signals in the array of optical signals apply different modulation signals.
14. The photonic neural network according to claim 12, wherein the modulator array applies different modulation signals to light of different wavelengths of the same optical signal in the optical signals of the third array.
15. The photonic neural network of claim 12, wherein the modulator array comprises a plurality of multi-wavelength light modulator units, wherein each of the multi-wavelength light modulator units comprises an optical interference unit, the optical interference The upper arm and the lower arm of the unit are respectively provided with a wavelength-sensitive phase shifter array to independently modulate the light of each wavelength in the input optical signal.
16. The photonic neural network according to claim 15, wherein the wavelength-sensitive phase shifter array comprises a plurality of phase shifters, and the plurality of phase shifters are associated with the light of each wavelength in the input optical signal. One-to-one correspondence.
17. The photonic neural network according to claim 16, wherein the wavelength-sensitive phase shifter array arranged on the upper arm and the wavelength-sensitive phase shifter array arranged on the lower arm are phase shifters corresponding to the same wavelength The sum of the phase-shifting parameters of the device is an integer multiple of 2π.
18. The photonic neural network according to any one of claims 1 to 10, further comprising:

    An electrical control module is coupled to the light receiving module, and the electrical control module is used for receiving and adjusting the processed signal.
19. The photonic neural network according to claim 18, wherein the electrical control module is further coupled to the light emission module to transmit the adjusted processed signal to the light emission as a signal to be processed module.
20. The photonic neural network according to claim 1, wherein the photonic neural network is used for image processing, image recognition, speech recognition, gene sequencing, quantum communication or quantum computing.

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