A multiplexing-based optical computing chip and its design method

Abstract

The present invention relates to the field of semiconductor technology, and more specifically to a multiplexing-based optical computing chip and a design method thereof, comprising a computing region formed by the intersection of a first waveguide and a second waveguide, comprising: a branch waveguide, each of which is connected to the first and second waveguides, wherein the branch waveguide is sequentially provided with a beam splitter, an intensity modulator, and a first signal converter, wherein the beam splitter is used to separate a specific proportion of optical signals, the intensity modulator is used to modulate the signal intensity of the optical signal to a specific value, and the first signal converter is used to set or maintain the optical signal in a specific mode, wherein the specific mode refers to the optical signal having a specific polarization direction and / or a specific order; and the second waveguide is provided with a computing unit, which is used to calculate the sum of the optical powers of multiple optical signals. The multiplexing scheme proposed by the present invention can improve the data processing capacity of the optical computing chip.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a multiplexing-based optical computing chip and a design method thereof. Background Art

[0002] With the application of 5G technology, the rise of live video streaming, and the surge in big data services, the demand for improved computing power in optical communication systems is becoming increasingly urgent. Currently, wavelength division multiplexing (WDM) is a commonly used method to improve data processing capabilities.

[0003] For example, CN118428430A discloses a silicon-based integrated all-optical deep neural network chip, its training method, and intelligent device. It discloses a silicon-based integrated all-optical deep neural network chip, its training method, and intelligent device. The chip includes: an input layer, an output layer, and multiple fully connected layers; each fully connected layer and output layer contains a beam splitter, a microcavity array, and a nonlinear gain unit. The beam splitter divides the wavelength signals output by the previous layer into M parts, and different rows of the microcavity array are used to weight the different parts of the divided signals; the nonlinear gain unit is used to perform nonlinear optical amplification calculations on each column to generate a regenerated signal; each fully connected layer uses a wavelength division multiplexing unit to multiplex the regenerated signal onto a waveguide and transmit it to the next layer; the output layer uses a photodetector array to perform photoelectric conversion on the regenerated signal to obtain the inference result.

[0004] However, the applicant noted that when wavelength division multiplexing (WDM) technology is applied to optical computing chips, signal loss is significant. This is particularly true with the increasing application of optical computing, such as the widespread use of artificial intelligence in fields like machine vision, natural language processing, and autonomous driving. This has placed higher demands on the data transmission and computing capabilities of optical computing chips. However, WDM's data processing capabilities are very limited, and losses are difficult to control, making it difficult to meet the computing needs of higher-specification optical computing chips.

[0005] In other words, as the requirements for chip integration and computing performance gradually increase, traditional multiplexing solutions are difficult to meet the real-time computing needs of data. Summary of the Invention

[0006] The purpose of the present invention is to provide a multiplexing-based optical computing chip and its design method, which partially solves or alleviates the above-mentioned deficiencies in the prior art, can improve the computing capacity of the optical computing chip, and at the same time achieve a good balance and optimization between its architectural complexity and computational accuracy.

[0007] In order to solve the above-mentioned technical problems, the present invention specifically adopts the following technical solutions:

[0008] A first aspect of the present invention is to provide a multiplexing-based optical computing chip, comprising:

[0009] a plurality of first waveguides;

[0010] a plurality of second waveguides arranged opposite to the first waveguide, wherein the first waveguides and the second waveguides intersect to form a plurality of calculation areas;

[0011] Wherein, the calculation area includes: a branch waveguide derived from the first waveguide, the first end and the second end of the branch waveguide are respectively connected to the first waveguide and the second waveguide, and the branch waveguide is provided with a beam splitter, an intensity modulation part, and a first signal conversion part in sequence along the direction from the first end to the second end thereof, wherein the beam splitter is used to separate a specific proportion of the first optical signal from the input optical signal from the first waveguide according to a set beam splitting ratio; the intensity modulation part is used to modulate the signal intensity of the input first optical signal to a specific value, and correspondingly generate and output a second optical signal; the first signal conversion part is used to set or maintain the second optical signal to a specific mode, and correspondingly generate and output a third optical signal, and the specific mode means that the third optical signal has a specific polarization direction and / or a specific order, and the third optical signal is transmitted to the corresponding second waveguide; wherein the third optical signals received at different positions of the same column of the second waveguide have different specific modes;

[0012] A calculation unit is provided corresponding to the second waveguide, and the calculation unit is used to calculate the sum of the optical powers of the plurality of third optical signals.

[0013] In some embodiments, the beam splitting portion adopts a symmetrical light splitting structure. Correspondingly, the first waveguide includes:

[0014] at least one row bus waveguide;

[0015] and a group of primary branch waveguides extending from the row bus waveguide, wherein the primary branch waveguides are connected to the bus waveguide using the symmetrical splitting structure to separate a primary optical signal of half the intensity from the input optical signal at the current position of the row bus waveguide; the primary branch waveguide includes: a first branch waveguide, and a second branch waveguide extending from the first branch waveguide, wherein the second branch waveguide is connected to the first branch waveguide using the symmetrical splitting structure to separate a secondary optical signal of half the intensity from the optical signal at the current position, wherein the secondary optical signal is input into the intensity modulation unit, and the intensity modulation unit outputs the corresponding second optical signal.

[0016] In some embodiments, the first waveguide further includes: a primary branch waveguide extending from the bus waveguide, wherein the primary branch waveguide is connected using a symmetrical splitting structure to separate a primary optical signal of half the intensity from the input optical signal at the current position.

[0017] In some embodiments, the specific order of the third optical signal input into the second waveguide decreases sequentially along a first direction, and correspondingly, the width of the second waveguide decreases sequentially along the first direction, wherein the first direction is opposite to the transmission direction of the optical signal in the second waveguide.

[0018] In some embodiments, the calculation unit is a photodetector; and / or the first signal conversion unit is an asymmetric directional coupler.

[0019] In some embodiments, the second waveguide is a multimode waveguide.

[0020] In some embodiments, the branch waveguide further includes: at least two first sub-waveguides, a combining waveguide connecting the at least two first sub-waveguides, and a second sub-waveguide for transmitting the signal of the combining waveguide to the second waveguide;

[0021] Correspondingly, the first waveguide includes: a first row of waveguides arranged in sequence, and at least one middle row of waveguides arranged in sequence;

[0022] A plurality of first-row calculation units are provided on the first-row waveguide, and the first-row calculation units include: a beam splitter provided on the first-row waveguide, and a first sub-waveguide connected through the beam splitter, wherein the first sub-waveguide is provided with an intensity modulator, and an output end of the first sub-waveguide is connected to the corresponding combiner waveguide;

[0023] The intermediate traveling waveguide is provided with a plurality of intermediate traveling calculation units, each of which includes: a beam splitter provided on the intermediate traveling waveguide, and a first sub-waveguide connected through the beam splitter, the first sub-waveguide being provided with an intensity modulator, and the first sub-waveguide being connected to the combining waveguide via a second signal conversion unit, wherein different traveling waveguides use light of different wavelengths as the input optical signals, and the second signal conversion unit is used to combine at least two optical signals of different wavelengths into one optical signal and input the combined optical signal into the combining waveguide;

[0024] The second sub-waveguide is connected to the second waveguide through the first signal conversion portion.

[0025] In some embodiments, the first waveguide is disposed in a first layer, the second waveguide is disposed in a second layer, and the first layer and the second layer are connected via the second sub-waveguide.

[0026] The present invention further provides a design method for the composite optical computing chip, which comprises the following steps:

[0027] S101, providing an optical computing chip, wherein the optical computing chip is provided with n first waveguides, and the first waveguides include: m traveling waveguides, the m traveling waveguides include: a first traveling waveguide and a middle traveling waveguides; and the m traveling waveguides are arranged at a first pitch;

[0028] S102, setting at least one set of different test conditions, the test conditions including: a first set value of m, and a second set value of the first spacing;

[0029] S103: Testing the optical computing chip according to at least one set of test conditions, and correspondingly collecting at least one set of first test results, where the first test results include: calculation results output by m*n second waveguides; wherein the calculation result is the sum of powers of the m*n optical signals output by the second waveguides, and the m traveling waveguides respectively use light of m different wavelengths as input optical signals;

[0030] S104, selecting at least one second test result that satisfies a first rule from the first test results, wherein the first rule requires that a number of calculated results having a difference ratio that is less than a set composite threshold and greater than a set reference number, where the difference ratio is |calculated result - standard result| / standard result;

[0031] S105, calculating at least one evaluation index L of the second test result according to the corresponding test condition, where L=αX+βY; wherein X is a first relative index of the first set value, Y is a second relative index of the second set value, α is a first weight, and β is a second weight; wherein the numerical value of the first set value is divided into at least two levels from small to large, and each level corresponds to a relative value for describing the first relative index; wherein the numerical value of the second set value is divided into at least two levels from small to large, and each level corresponds to a relative value for describing the second relative index;

[0032] S106: Recommend corresponding test conditions to the user according to the evaluation index L as a preferred design solution.

[0033] In some embodiments, an order difference between two third optical signals coupled into the second waveguide is greater than a set order threshold, and the test condition further comprises: a third set value for the order difference; the value of the third set value is divided into at least two levels from small to large, and each level corresponds to a relative value for describing the third relative indicator;

[0034] Correspondingly, the evaluation index L is: L=αX+βY+γZ1, γ is the third weight, and Z1 is the third relative index of the order difference.

[0035] In some embodiments, the test condition further includes: a fifth set value of n; correspondingly, the value of the fifth set value is divided into at least two levels from small to large, and the levels correspond to a relative value describing a fifth relative indicator;

[0036] Correspondingly, the evaluation index L is: L=αX+βY+εZ3;

[0037] Wherein, ε is the fifth weight, and Z3 is the fifth relative index.

[0038] Beneficial technical effects:

[0039] The present invention provides an optical computing chip that synchronously transmits and calculates large data optical signals through mode differentiation. This transmission of differentiated modes of multiple types of signals in the second waveguide can simplify the overall architecture of the optical computing chip. For example, it can directly sum the power of multiple optical signals through a photodetector at the end of the second waveguide, eliminating the need to set up a power calculation device at each first waveguide to perform independent signal calculations. In other words, this mode-differentiated operating mechanism can improve data transmission efficiency through unified computing processing. That is, optical signals from different first waveguides can be quickly converted and coupled to the second waveguide only through mode changes, and continue to be transmitted at high speed in the form of light, with only one overall calculation performed at the end of the second waveguide. Therefore, the overall computing efficiency of the optical computing chip is relatively high.

[0040] Furthermore, to reduce computational errors in large-scale optical computing chips, an array structure based on tree-like cascaded equal-proportional splitting can be preferably adopted. Specifically, the present invention also provides a restrictive splitting mechanism that mandates that each splitting position in the tree-like cascade structure use the same proportional beam for splitting adjustment, thereby preventing the splitting process from introducing further errors during mode conversion.

[0041] On the other hand, in order to reduce the signal crosstalk and difficult mode management problems faced by large-scale optical computing chips when performing differentiated light mode transmission, a differentiated transmission mechanism based on mode and wavelength collaboration has been proposed (that is, a composite optical computing chip with high computing speed and low loss characteristics is provided). This reduces the difficulty of mode differentiation setting while reducing the risk of signal crosstalk.

[0042] This hybrid, multi-stage cascade architecture facilitates a balanced design between the difficulty of signal differentiation and signal loss. Specifically, by introducing a limited number of input optical signals of different wavelengths into the first waveguide (i.e., a group of traveling waveguides), the difficulty of order differentiation can be reduced. This reduces the number of necessary orders for mode differentiation to m, or 1 / n of the original number of orders. This significantly reduces the technical difficulty of implementing mode differentiation for large-scale optical computing chips (such as 124x124 optical computing chips). Furthermore, by differentially coupling wavelengths and orders (i.e., by limiting the introduction of only a limited number of optical signals of different wavelengths through multiple groups of traveling waveguides), the technical difficulty and cost of multi-wavelength light sources can be reduced. Thus, by synergizing the number of wavelengths and orders, a balance can be achieved between light source cost and signal crosstalk.

[0043] Furthermore, to facilitate implementation of the proposed hybrid optical computing chip, this invention also proposes a design method for the hybrid optical computing chip. By comprehensively evaluating the reliability and dimensional characteristics of the optical computing chip based on two key factors: the number of differentially configured wavelengths (m) and the initial spacing between traveling waveguides (which can mitigate the risk of crosstalk to a certain extent), the method facilitates rapid selection of appropriate design specifications for this novel hybrid optical computing chip.

[0044] In other words, the present invention dually evaluates the number of wavelengths that can be accommodated in a traveling waveguide and the spacing between the traveling waveguides, thereby alleviating potential signal crosstalk or signal quality issues while increasing the computational throughput of the optical computing chip. It is important to note that the applicant has observed that while optical input signals of varying wavelengths improve computational performance, they can also easily introduce signal loss. Therefore, by dually evaluating the number of wavelengths and the spacing setting, the potential increase in computational error in large-scale optical computing chips can be minimized, making the composite computing chip solution easier to implement.

[0045] Furthermore, the present invention also proposes a design scheme that can comprehensively evaluate the spacing of the combined waveguides, the number of wavelength differences, and the spacing of the traveling waveguides. Similarly, as the scale of optical computing chips continues to expand, the multi-level cascade scheme of the composite optical computing chip will become more complicated. In particular, in the actual chip architecture, it is difficult to achieve such Figure 5 or Figure 6The ideal straight-line arrangement can be problematic, as waveguide curvature can further increase the intensity or loss differences between signals of different orders, as well as the risk of crosstalk. To address this, the present invention prioritizes the spacing between the combining waveguide and the secondary waveguide as a key factor, comprehensively evaluating signal loss and crosstalk, thereby achieving a balance between wavelength differentiation and order differentiation.

[0046] Preferably, the present invention also proposes a scheme for layered arrangement of the first and second waveguides. On the one hand, the first and second waveguides are respectively arranged in different layers, and the interlayer spacing is controlled to reduce the mode crosstalk caused by scattering; on the other hand, it is also conducive to realizing a flexible layout of the second waveguide and reducing the loss and crosstalk introduced by waveguide bending.

[0047] Furthermore, the present invention can also comprehensively consider the degree of order differentiation (such as the order distribution corresponding to different first waveguides, that is, the difference between the orders corresponding to adjacent first waveguides) to balance the wavelength differentiation and order differentiation setting resources of the composite optical computing chip. On the basis of ensuring the overall operational feasibility, the difficulty of setting wavelength differentiation and order differentiation is reduced (reducing the performance requirements for the first and second signal conversion units). Therefore, by collaboratively managing signal loss and signal crosstalk issues, it can be applied to the optical computing needs of large-scale optical computing chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the embodiments or the description of the prior art. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the various elements or parts are not necessarily drawn according to the actual scale. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without inventive work.

[0049] Figure 1 Schematic diagram of an array structure of an optical computing chip in an exemplary embodiment of the present invention;

[0050] Figure 2a Schematic diagram of the electric field amplitude distribution of light with different mode orders along the transverse direction (perpendicular to the transmission direction);

[0051] Figure 2b Schematic diagram of the distribution of each order mode field in the TE and TM directions in the waveguide;

[0052] Figure 3 is a schematic structural diagram of a second waveguide in an exemplary embodiment of the present invention;

[0053] Figure 4 Schematic diagram of the array structure of tree-like cascaded optical computing chips in an exemplary embodiment of the present invention;

[0054] Figure 5 is a schematic diagram of a partial structure of a composite optical computing chip in an exemplary embodiment of the present invention;

[0055] Figure 6 Schematic diagram of the structure of a composite optical computing chip in an exemplary embodiment of the present invention;

[0056] Figure 7 The figure is a flow chart of the design method steps in an exemplary embodiment of the present invention.

[0057] Summary of reference numerals:

[0058] First waveguide 1, second waveguide 2, branch waveguide 3 (also called: third waveguide), intensity modulation unit 6, first signal conversion unit 7, beam splitting unit 8, row bus waveguide 11, first-level branch waveguide 12, first branch waveguide 121, second branch waveguide 122, first sub-waveguide 31, combining waveguide 32, second sub-waveguide 33, second signal conversion unit 34, first row waveguide 41, intermediate row waveguide 42; waveguide core layer 01, waveguide cladding 02, wafer substrate 03. DETAILED DESCRIPTION

[0059] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0060] Herein, suffixes such as "module," "component," or "unit" used to represent elements are only used to facilitate description of the present invention and have no specific meaning. Therefore, "module," "component," or "unit" may be used interchangeably.

[0061] As used herein, terms such as "upper," "lower," "inner," "outer," "front," "back," "one end," and "the other end" indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0062] As used herein, unless otherwise expressly specified or limited, the terms "installed," "provided with," and "connected" should be understood broadly. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention on a case-by-case basis.

[0063] As used herein, "and / or" includes any and all combinations of one or more of the associated listed items.

[0064] Herein, "plurality" means two or more than two, ie, it includes two, three, four, five, etc.

[0065] As used in this specification, the term "about" typically means + / - 5% of the stated value, more typically + / - 4% of the stated value, more typically + / - 3% of the stated value, more typically + / - 2% of the stated value, even more typically + / - 1% of the stated value, and even more typically + / - 0.5% of the stated value.

[0066] In this specification, certain embodiments may be disclosed in a format that is within a range. It should be understood that this description of "within a range" is merely for convenience and brevity and should not be interpreted as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered to have specifically disclosed all possible subranges and individual numerical values ​​within this range. For example, the description of a range of 1-6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within this range, such as 1, 2, 3, 4, 5, and 6. Regardless of the breadth of the range, the above rules apply.

[0067] Computational area: In this article, the computational area refers to the area formed by one or more computational units. Generally, an N*N optical computing chip (hereinafter referred to as a chip) means that it has N*N computational units. For example, Figure 1 For example, a computing unit generally refers to a functional unit comprising a first waveguide segment, a beam splitting section, an intensity modulating section 6, a branch waveguide segment, and a second waveguide segment. Specifically, when the computing unit is in the second or subsequent row (i.e., not in the first row) along the direction of optical signal transmission in the second waveguide, it refers to a functional unit comprising the first waveguide segment, a beam splitting section, an intensity modulating section 6, a branch waveguide segment, a second waveguide segment, and a signal conversion section (e.g., the first signal conversion section or the second signal conversion section).

[0068] For example, in Figure 1 In the exemplary embodiment shown, a computing region may refer to a computing unit.

[0069] For example, in Figure 6 In the exemplary embodiment shown, when the first waveguide further includes m running waveguides, the computational region formed by the intersection of the first and second waveguides can also be referred to as the functional region formed by the m computational units. Specifically, the computational region in this exemplary embodiment includes one first-row computational unit and a intermediate-row computational units.

[0070] See also Figure 2b As shown, a waveguide is sequentially configured with a waveguide core 01, a waveguide cladding 02, and a wafer substrate 03. Waveguides conduct light based on the principle of total internal reflection. Their lateral spatial confinement allows for stable transmission of light field amplitude distributions that meet lateral resonance conditions (corresponding to specific wave vectors or effective refractive indices), known as waveguide modes.

[0071] Light waves are electromagnetic waves, and the polarization direction of the optical waveguide mode refers to the relationship between the direction of the electric field vector and the propagation plane. For example, the TE and TM polarization directions refer to the direction in which the main components of the electric field are tangential and normal to the wafer substrate, respectively (e.g. Figure 2b (indicated by the arrow in the middle).

[0072] According to the number of nodes (nodes are points where the field strength is 0) in the stable mode field distribution formed by the lateral resonance of the waveguide, it can be divided into fundamental mode TE0, TM0 (number of nodes is 0), first-order modes TE10, TM10, TE01, TM01 (number of nodes is 1), and higher-order modes such as TE20, TM20, etc. (see Figure 2b (as shown). Correspondingly, different light modes refer to optical signals of different orders (or, in other words, numbers). Each order mode has a specific electric field distribution, effective refractive index, and group refractive index. Within a uniform waveguide, the modes are orthogonal to each other and propagate independently without conversion. The total optical power within the waveguide is the sum of the powers of all the modes.

[0073] For example, see Figure 2a As shown in the figure, taking a one-dimensional slab waveguide as an example, the distribution of modes TE0 through TE3 is shown. If the number of nodes in the lateral distribution is e, then this mode is the e-th-order mode, TEe. Light waves are transverse waves. In integrated optical waveguides, when the electric field (primarily in the direction of the electric field) is normal to the wafer, it is a TM wave; when it is tangential to the wafer, it is a TE wave.

[0074] In the present invention, light (such as optical signals) is transmitted in the same waveguide using different modes, which can avoid the use of low-speed multi-path parallel electrical summing devices, thereby simplifying the structure of the chip system and improving the data processing (or calculation) speed.

[0075] With the rise of big data services such as machine vision, natural language processing, and autonomous driving, higher requirements are being placed on the data processing capabilities of optical computing chips. To address this, the present invention proposes an optical computing chip with high data processing speed and low loss.

[0076] Example 1

[0077] See also Figure 1 As shown, the present invention provides a multiplexing-based optical computing chip, comprising:

[0078] a plurality of first waveguides 1;

[0079] A plurality of second waveguides 2 arranged opposite to the first waveguide, wherein the first waveguide 1 and the second waveguide 2 intersect to form a plurality of calculation areas;

[0080] Wherein, the calculation area includes: a branch waveguide 3 (also referred to as: a third waveguide) extending from the first waveguide 1, the first end and the second end of the branch waveguide 3 are connected to the first waveguide and the second waveguide respectively, and the branch waveguide is provided with a beam splitter 8, an intensity modulation part 6, and a first signal conversion part 7 in sequence along the direction from the first end to the second end thereof, wherein the beam splitter 8 is used to separate a specific proportion of optical signals from the first waveguide 1 according to a set beam splitting ratio (from the input optical signal); the intensity modulation part 6 is used to modulate the signal intensity of the input optical signal to a specific value, and correspondingly generate and output a second optical signal, and the first signal conversion part 7 is used to set or maintain the second optical signal to a specific mode, and correspondingly generate and output a third optical signal, wherein the specific mode refers to that the optical signal has a specific polarization direction and / or a specific order, and the third optical signal is transmitted to the corresponding second waveguide; wherein the third optical signals received at different positions of the same column of the second waveguide have different specific modes;

[0081] A calculation unit is provided corresponding to the second waveguide, and the calculation unit is used to calculate the sum of the optical powers of the plurality of third optical signals.

[0082] It should be noted that, in some embodiments, the branch waveguide 3 is mainly used to extract a specific proportion of optical signals from the first waveguide 2 , and therefore it can also be regarded as a part of the first waveguide 2 .

[0083] In some embodiments, the calculation unit may be a photodetector disposed at the end of the second waveguide. The beam splitting unit may be provided with a beam splitter, and the intensity modulation unit may be provided with an intensity modulator.

[0084] See also Figure 1As shown, a calculation area in this embodiment specifically refers to a calculation unit, and the first waveguides in the i-1th row, the i-th row, and the i+1th row are arranged in sequence along the transverse direction, and the second waveguides in the j-1th column, the j-th column, and the j+1th column are arranged in sequence along the transverse direction. Correspondingly, in the calculation unit composed of the waveguides in the i-th row and the j-th column, the optical power output by the beam splitter is , the transmittance is After the intensity modulator, the optical power is The modulator output light beam is transmitted in TE00 mode, and after passing through the signal conversion unit, it is converted into a specific mode of the column bus multimode waveguide for transmission; the output light of each row is coupled to N different modes of the column bus multimode waveguide and transmitted to the photodetector of the column. The detection light power is the sum of the power of each mode. , realizing the summation of the optical power of the calculation units in this column.

[0085] In this embodiment, an input TE 00 mode beam can be converted to the TE / TM N0 mode of the bus waveguide without affecting the transmission of other modes within the bus waveguide. When the effective refractive index of the TE 00 mode in the input waveguide (equivalent to the first waveguide) and the TE / TM K0 mode in the bus waveguide (equivalent to the second waveguide) are the same, optical power will be completely and gradually transferred from one waveguide to the other during parallel transmission. Accordingly, the signal conversion unit can be equipped with an asymmetric directional coupler.

[0086] It's worth noting that the multimode optical signal transmission mechanism employed in this invention within the bus waveguide allows for a single photodetector at the end of the bus waveguide to calculate the sum of the power of all optical signals simultaneously, eliminating the need for separate power calculations at each computational unit. This transmission mechanism simplifies the device design of the computational array and improves computational speed.

[0087] Specifically, the optical transmission mechanism of different modes provided by the present invention avoids the need for on-chip deployment of multi-wavelength lasers, such as optical frequency combs or multiple lasers with different wavelengths. Reducing the number of lasers also simplifies chip system packaging and reduces costs. Furthermore, reducing the number of required signal wavelengths avoids the need for large-scale feedback circuits for wavelength stability control, simplifying system complexity.

[0088] Preferably, in this embodiment, each row of first waveguides uses an optical signal with the same wavelength as the input optical signal.

[0089] Of course, in other embodiments, when the scale of the computing array is further expanded, optical signals of different wavelengths may also be used as input optical signals.

[0090] Preferably, along the transmission direction of the column bus waveguide, the order of the mode is prioritized from low order to high order. For example, in some embodiments, the input light of rows 1 to 4 is converted into the TE00, TE10, TE20, and TE30 modes of the column bus waveguide, respectively; or, in other embodiments, the input light of rows 1 to 4 is converted into the TE00, TE10, TM00, and TM10 modes of the column bus waveguide, respectively. In this embodiment, when the polarization direction is converted, a polarization rotator needs to be added before the mode multiplexer to convert the TE00 mode into the TM00 mode. Preferably, the second waveguide uses a waveguide that only supports TE00 and / or TM00 modes to limit the mode type and avoid coupling of different optical signals during sidewall scattering and bending radiation, which may cause large deviations in the optical signal during transmission.

[0091] Ideally, the TE 00 mode is fully converted to the higher-order TE / TM N0 mode. However, due to structural deviations in the mode multiplexer, some of the input beam may remain in the input waveguide or be partially converted (or crosstalked) to another mode, TE / TM K0. For example, when converting from TE00 to TE20, a small portion of the light may be converted to TE10 due to its similar effective refractive index, causing crosstalk. Furthermore, in bus waveguides, structures such as waveguide crossings and rough sidewalls can cause some of the power in the transmission mode to be converted to other modes, thus causing crosstalk.

[0092] To address this issue, this embodiment prefers a mode multiplexer with an adiabatic gradient asymmetric coupling structure to minimize the impact of process variations on coupling efficiency and crosstalk. Specifically, the widths of the two mutually coupled waveguides in the adiabatic gradient asymmetric coupling structure are adiabatically tapered along the transmission direction, maintaining the original order of the transmitted light mode with only the distribution width changing. Because mode coupling primarily occurs within the waveguide width range of effective refractive index matching, changes in waveguide width primarily affect the coupling position, rather than coupling efficiency, when process variations exist.

[0093] Further, see Figure 3 As shown, the column waveguide width gradually increases with the number of rows, supporting a larger number of modes. Signals are coupled sequentially from low to high to reduce modal crosstalk. Preferably, the sidewall roughness of the silicon waveguide can be reduced through processes such as post-etch annealing and sidewall oxidation. Preferably, materials with a low refractive index, such as doped silicon oxide, silicon nitride, or silicon oxynitride, can be selected for the column bus waveguide to reduce sidewall scattering intensity.

[0094] In this embodiment, the risk of crosstalk generated by multi-mode optical signals can be reduced by optimizing the sidewall scattering intensity of the column bus waveguide.

[0095] In some embodiments, see Figure 4As shown, the first waveguide includes:

[0096] at least one row bus waveguide 11;

[0097] and a group of primary branch waveguides 12 extending from the row bus waveguide 11, wherein the primary branch waveguides 12 are connected to the row bus waveguide 11 using a symmetrical splitting structure (equivalent to the beam splitting portion) to separate a primary optical signal of half the intensity from the input optical signal at the current position of the row bus waveguide 11; the primary branch waveguide 12 further includes: a first branch waveguide 121, and a second branch waveguide 122 extending from the first branch waveguide 121, wherein the second branch waveguide 122 is connected to the first branch waveguide 121 using a symmetrical splitting structure to separate a secondary optical signal of half the intensity from the optical signal at the current position (in other words, the first branch waveguide and the second branch waveguide are respectively input with optical signals of the same intensity), the secondary optical signals are correspondingly input to the intensity modulation portion, and the intensity modulation portion outputs the corresponding second optical signal.

[0098] It is understood that in this embodiment, the branch waveguide 3 (e.g., the primary branch waveguide 12) can also be considered as a portion extending from the first waveguide. In some embodiments, the branch waveguide can be a waveguide structure extending directly from the first waveguide (specifically, the row bus waveguide 11). Alternatively, in other embodiments, the branch waveguide can be a waveguide structure connected to the first waveguide via a beam splitter or other connecting device.

[0099] In some embodiments, the first waveguide further includes: a primary branch waveguide (equivalent to a section of branch waveguide 3) extending from the bus waveguide 11, and the primary branch waveguide is connected using a symmetrical splitting structure to separate a primary optical signal of half the intensity from the optical signal at the current position.

[0100] This embodiment provides an array structure based on tree-like cascaded equal-proportional splitting. In other words, for transmission scenarios involving optical signals of different specific modes, the present invention proposes a restrictive splitting mechanism to reduce the potential deviations in optical signal modulation caused by uneven splitting, thereby minimizing potential transmission errors in signal transmission on large-scale computing chips.

[0101] It is worth noting that due to manufacturing processes, different beam splitters may have certain deviations in their splitting performance. In particular, when the beam splitter splits light signals in different proportions, the splitting deviations that may occur during actual operation are difficult to predict. To address this, the present invention proposes a restrictive splitting mechanism that requires that each splitting position in the tree-like cascade structure use the same proportion of light beams for splitting adjustment, thereby avoiding the introduction of further errors in the splitting process during mode division multiplexing.

[0102] Preferably, the present invention adopts a beam splitter with a symmetrical structure, which has higher reliability when applied to equal-proportional light splitting.

[0103] In some embodiments, the second waveguide is a multimode waveguide.

[0104] Correspondingly, to meet the requirements of high data computing power and low loss, the present invention also provides a composite multiplexing computing system (or composite optical computing chip) based on cross-connection of mode division and wavelength division. Specifically, in some embodiments, the branch waveguide (also referred to as the third waveguide) extending from the first waveguide further includes: at least two first sub-waveguides 31, a combining waveguide 32 connecting the at least two first sub-waveguides 31, and a second sub-waveguide 33 for transmitting the signal of the combining waveguide to the second waveguide 2;

[0105] Correspondingly, the first waveguide includes: a first row of waveguides 41 arranged in sequence, and at least one intermediate row waveguide 42 arranged in sequence, such as a intermediate row waveguides; and at least two first sub-waveguides 31 are respectively connected to the first row waveguide 41 and the intermediate row waveguide 42, and the output ends of the two first sub-waveguides 31 are connected through a combining waveguide 32, and the output end of the combining waveguide 32 is connected to the second waveguide 2 through a second sub-waveguide 33;

[0106] Correspondingly, a plurality of first-row calculation units are formed along the length direction of the first-row waveguide 41. The first-row calculation units include: a beam splitter provided on the first-row waveguide 41, and a first sub-waveguide 31 connected through the beam splitter. The first sub-waveguide 31 is provided with an intensity modulator, and the output end of the first sub-waveguide 31 is connected to the corresponding combiner waveguide 32.

[0107] The intermediate row waveguide 42 is provided with a plurality of intermediate row calculation units along its length. The intermediate row calculation units include: a beam splitter provided on the intermediate row waveguide 42, and a first sub-waveguide 31 connected through the beam splitter. The first sub-waveguide 31 is provided with an intensity modulator, and the first sub-waveguide 31 is connected to the combining waveguide 32 via a second signal conversion unit 34. The second signal conversion unit is used to combine at least two optical signals of different wavelengths into a single optical signal and input the combined optical signal into the combining waveguide 32.

[0108] That is, a group of a+1 optical signals of different wavelengths are coupled in the combining waveguide 32, and the group of optical signals is combined into a beam of light by the second signal conversion unit for transmission in the second waveguide. Since different optical signals have different wavelengths, they can be distinguished and identified by the detector when they are synchronously transmitted in the same second waveguide, so as to complete the calculation of the output results of different calculation areas.

[0109] See below. Figure 5-Figure 6 The multiplexing mode in the present invention is explained as follows:

[0110] Figure 6 The diagram shows a 4x4 array of computing units. Two sets of first waveguides are provided. The first row of waveguides (equivalent to the first row of waveguides 41) receives first incident light (i.e., an optical signal) with a first wavelength λ1, while the second row of waveguides (equivalent to the middle row of waveguides 42) receives second incident light with a second wavelength λ2. The optical signals output by the two rows of waveguides undergo intensity modulation and are then combined into a combining waveguide 32 via a wavelength division multiplexer. The first and second wavelengths are unequal. Furthermore, the optical signal in combining waveguide 32 is transferred to the second waveguide 2 for transmission in TE0 mode.

[0111] The first row of traveling waveguides in the second first waveguide can similarly input first incident light of the first wavelength λ1, while the second row of traveling waveguides input second incident light of the second wavelength λ2. The optical signals output by the two traveling waveguides undergo intensity modulation and are then combined into a combining waveguide 33 via a wavelength division multiplexer. Furthermore, the optical signals in the combining waveguide are now adjusted to the TE1 mode by a signal conversion unit and transferred into the second waveguide 2 for transmission. At this point, four optical signals are input into the second waveguide, each with a different wavelength or order. Therefore, they can be transmitted simultaneously in the second waveguide without causing interference or other effects.

[0112] It is noteworthy that the composite serial connection configuration of the present invention can improve the tolerance of the optical computing chip for the synchronous transmission of a large number of optical signals without increasing the number of traveling waveguides (or first waveguides).

[0113] Preferably, the second signal conversion unit in the present invention can adopt a wavelength division multiplexer with a micro-ring structure, which has a high wavelength correlation; the first signal conversion unit adopts an asymmetric directional coupler structure, whose working performance is insensitive to wavelength. It can convert optical signals in a certain wavelength range λ1~λ2 from TE0 to the same order mode, realizing mode and wavelength combination.

[0114] In some embodiments, the first waveguide is provided in a first layer, the second waveguide is provided in a second layer, and the first layer and the second layer are connected via the second sub-waveguide 33. In this embodiment, in order to alleviate the crosstalk problem in large-scale optical computing chips, a double-layer waveguide arrangement with a large spacing is preferably used.

[0115] In some embodiments, the first layer further includes: a first sublayer and a second sublayer, and the first sublayer and the second sublayer are respectively arranged on the upper and lower sides of the second layer, and correspondingly, the first waveguides adjacent along the signal transmission direction of the second waveguide can be respectively arranged in different sublayers. In this embodiment, a cross-layered layout mode is also proposed for the computing chip with wavelength division and mode division multiplexing distributed in series, thereby combining the double reuse mode and the layered arrangement of the lines so that the computing chip can accommodate more optical signal types while reducing the possibility of crosstalk between different signals. In other words, through the superposition of multiplexing modes and the position layout in physical space, the optical computing chip's tolerance for optical signal types is improved, while the difference in optical signals between adjacent waveguides can be increased, and the interference problem between lines can be alleviated.

[0116] In this embodiment, m first waveguides are provided in a large-scale optical computing chip, and n traveling waveguides are provided in the first waveguide (e.g., one first traveling waveguide and a intermediate traveling waveguides, i.e., n = a + 1). Correspondingly, m*n different types of optical signals can be coupled in a second waveguide, where different types refer to optical signals having different wavelengths or different orders.

[0117] In other words, for an N*N (N=m*n) computing array, using a single order adjustment would require n*m ​​optical signals of different orders to complete the computing task. As the chip size increases (for example, a 124*124 computing chip), 124 orders of optical signals would be required. Conversely, the proposed method can reduce the required order to m, or 1 / n of the original number.

[0118] On the one hand, this reduction in order can reduce the pressure of order setting, thereby reducing the performance requirements for the first and second signal conversion parts. On the other hand, it is also beneficial to reduce the probability of crosstalk between adjacent lines. Specifically, the reduction in order is also beneficial to increase the order difference between adjacent waveguides to alleviate the risk of crosstalk between adjacent waveguides.

[0119] In some embodiments, the specific order of the third optical signal input into the second waveguide decreases sequentially along a first direction, and correspondingly, the width of the second waveguide decreases sequentially along the first direction, wherein the first direction is opposite to the transmission direction of the optical signal in the second waveguide.

[0120] Example 2

[0121] Furthermore, for such a large-scale composite optical computing chip with multiple waveguides (e.g., a combining waveguide is also introduced into the first waveguide), the present invention also provides a design method to coordinate the size and computing accuracy of the optical computing chip. Figure 7As shown, the method includes the steps of:

[0122] S101, providing an optical computing chip, wherein the optical computing chip is provided with n first waveguides, and the first waveguides include: m traveling waveguides; and the m traveling waveguides are arranged at a first pitch;

[0123] It can be understood that the optical computing chip can be the composite optical computing chip described in any of the above embodiments.

[0124] S102, setting at least one set of different test conditions, the test conditions including: a first set value of m, and a second set value of the first spacing;

[0125] For example, in some embodiments, optical computing chips with different specification ranges (e.g., different design size requirements) may have a number of set reference values. For example, the first set value may be selected from H1 reference values, and the second set value may be selected from H2 reference values. Alternatively, these test reference values ​​may be manually set by engineers based on historical experience. Accordingly, during the initial design phase, multiple sets of test conditions may be set according to the above method, so that appropriate design specifications can be selected through evaluation of these multiple test conditions.

[0126] S103: Testing the optical computing chip according to at least one set of test conditions, and correspondingly collecting at least one set of first test results, the test results including: calculation results output by m*n second waveguides; wherein the calculation result is the sum of powers of m*n optical signals output by the second waveguides, and the m traveling waveguides respectively use light of m different wavelengths as input optical signals;

[0127] For example, in some embodiments, the optical computing chip may be simulated and tested using simulation software, or a physical chip may be run and tested.

[0128] S104, selecting at least one second test result that satisfies a first rule from the first test results, wherein the first rule requires that a number of calculated results having a difference ratio that is less than a set composite threshold and greater than a set reference number, where the difference ratio is |calculated result - standard result| / standard result;

[0129] For example, in some embodiments, in the first rule, a calculation result is considered to be relatively reliable only when the deviation between the calculation result and the standard result is less than a set composite threshold, and when multiple calculation results are all determined to be reliable, the current test result is considered to be reliable as a whole.

[0130] In this embodiment, the calculation result refers to the sum of the optical powers calculated by the photodetectors. Accordingly, during the testing process, at least one standard matrix multiplication method can be selected as a test solution. This standard matrix multiplication method has a predetermined, accurate calculation result (i.e., a standard result). By running this standard matrix multiplication method on the optical computing chip and comparing the actual calculation result output with the standard result, the accuracy of the optical computing chip can be verified. This testing process can thus comprehensively assess the size, optical loss, and optical crosstalk of the composite optical computing chip.

[0131] S105, calculating at least one evaluation index L of the second test result, where L=αX+βY (equivalent to the first evaluation model); wherein X is a first relative index of a first set value, Y is a second relative index of a second set value, α is a first weight, and β is a second weight.

[0132] For example, in some embodiments, the first setting value is divided into at least two levels from small to large, and each level corresponds to a relative value for describing the relative index. For example, it can be divided into level 1 and level 2, and its relative index can be set to 1 or 2 accordingly.

[0133] For example, in some embodiments, the second setting value is divided into at least two levels in ascending order according to its numerical value, and each level corresponds to a relative value for describing the relative indicator.

[0134] Of course, it is understandable that the first relative index is mainly used to describe the number of optical signals of different wavelengths, while the second relative index is mainly used to evaluate the size of the first interval, and the specific relative values ​​can be freely adjusted.

[0135] S106: Recommend corresponding test conditions to the user according to the evaluation index L as a preferred design solution.

[0136] For example, when the evaluation index L is relatively small, it means that the performance requirements of the corresponding signal conversion unit and the overall size of the optical computing chip are relatively limited, so it can be used as a preferred design solution.

[0137] Alternatively, in some embodiments, feasible design solutions can be quickly screened out through the above design solutions, so that engineers can quickly obtain initial design solutions, which is beneficial for subsequent rapid specification.

[0138] Furthermore, in some embodiments, the test conditions further include an order difference setting condition. Specifically, m first waveguides each input m optical signals of different orders (i.e., the aforementioned third optical signals) into the second waveguide, and the order difference between adjacent optical signals (i.e., the third optical signals input from adjacent first waveguides into the second waveguide) is greater than a set order threshold. Accordingly, the test conditions may include two or more order difference values.

[0139] For example, in this embodiment, the multiple test conditions may be: test condition 1 (where m=2, first spacing=D1, order difference=1), test condition 2 (where m=3, first spacing=D1, order difference=1), test condition 3 (where m=2, first spacing=D2, order difference=1), test condition 4 (where m=3, first spacing=D2, order difference=1), test condition 5 (where m=2, first spacing=D1, order difference=2), test condition 6 (where m=3, first spacing=D1, order difference=2), test condition 7 (where m=2, first spacing=D2, order difference=2), and test condition 8 (where m=3, first spacing=D2, order difference=2). Correspondingly, simulation tests may be performed on the eight test conditions respectively to obtain the calculation results after their execution.

[0140] Correspondingly, the evaluation index can also adopt the following model: L=αX+βY+γZ1 (equivalent to the second evaluation model); wherein γ is the third weight, and Z1 is the third relative index of the order difference. For example, according to the numerical value of the order difference, it can also be divided into at least two levels from small to large, and each level corresponds to a relative value to describe the relative index.

[0141] In this embodiment, the performance requirements of the first and second signal conversion units are comprehensively evaluated using the first and third relative indicators (in other words, this embodiment comprehensively analyzes the signal loss and crosstalk issues using the first and third relative indicators). At the same time, the size and crosstalk issues of the optical computing chip are simultaneously evaluated using the second relative indicator. Thus, this evaluation indicator model can achieve a certain balance between the wavelength division and mode division multiplexing mechanisms while taking into account the size scale, so that the loss caused by wavelength differences and the errors caused by signal crosstalk in this scheme are generally controlled.

[0142] In particular, in some embodiments, the relative index may also be directly represented by the order difference.

[0143] Furthermore, in some embodiments, the test conditions further introduce a setting parameter of the combiner waveguide, namely, a second spacing between the combiner waveguide and the second waveguide. Correspondingly, the combiner waveguide and the second waveguide are arranged with the second spacing. Correspondingly, the evaluation index is:

[0144] L = αX + βY + δZ² (equivalent to the third evaluation model); δ is the fourth weight, and Z² is the third relative index of the second interval. The second interval can be divided into at least two levels, from small to large, based on its numerical value. Each level corresponds to a relative value used to describe the fourth relative index.

[0145] Of course, in other embodiments, when higher performance requirements are placed on the optical computing chip, a fourth evaluation model, ie, L=αX+βY+γZ1+δZ2, may also be used.

[0146] In some embodiments, the width of the second waveguide gradually increases along the transmission direction of the second waveguide.

[0147] In some embodiments, the test conditions also include: a fifth set value of n; correspondingly, the numerical value of the fifth set value is divided into at least two levels from small to large, and the level corresponds to a relative value describing a fifth relative indicator; correspondingly, the evaluation index L is: L=αX+βY+εZ3; wherein ε is the fifth weight, and Z3 is the fifth relative indicator.

[0148] For example, in Figure 6 In the optical computing chip of the illustrated specifications, n is 2. Of course, as the specifications of the optical computing chip gradually expand, n can be flexibly selected and set according to the number of traveling waveguides in the first wavelength and the overall specifications of the optical computing chip.

[0149] In this embodiment, the composite conditions of the composite optical computing chip are preferably selected based on the two main dimensions of the number of wavelengths and the number of orders, so as to quickly find a better balance between reducing the technical difficulty of multi-wavelength light sources and the technical difficulty of multi-order light source settings.

[0150] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0151] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), including a number of instructions for enabling a computer terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0152] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A multiplexing-based optical computing chip, characterized in that: include: a plurality of first waveguides (1); a plurality of second waveguides (2) arranged opposite to the first waveguide, wherein the first waveguide (1) and the second waveguide (2) intersect to form a plurality of calculation areas; The calculation area includes: a branch waveguide (3) derived from the first waveguide (1), the first end and the second end of the branch waveguide (3) are connected to the first waveguide and the second waveguide respectively, and the branch waveguide is provided with a beam splitter (8), an intensity modulation part (6), and a first signal conversion part (7) in sequence along the direction from the first end to the second end thereof, wherein the beam splitter is used to separate a specific proportion of the first optical signal from the input optical signal from the first waveguide according to a set beam splitting ratio; the intensity modulation part is used to modulate the signal intensity of the input first optical signal to a specific value, and correspondingly generate and output a second optical signal; the first signal conversion part is used to set or maintain the second optical signal to a specific mode, and correspondingly generate and output a third optical signal, the specific mode means that the third optical signal has a specific polarization direction and / or a specific order, and the third optical signal is transmitted to the corresponding second waveguide; wherein the third optical signals received at different positions of the same column of the second waveguide have different specific modes; A calculation unit is provided corresponding to the second waveguide, and the calculation unit is used to calculate the sum of the optical powers of the plurality of third optical signals.

2. The optical computing chip according to claim 1, characterized in that: The beam splitting portion (8) adopts a symmetrical light splitting structure, and the first waveguide includes: at least one row bus waveguide (11); and a group of primary branch waveguides (12) extending from the row bus waveguide (11), wherein the primary branch waveguides (12) are connected to the row bus waveguide (11) using the symmetrical splitting structure to separate a primary optical signal of half the intensity from the input optical signal at the current position of the row bus waveguide (11); the primary branch waveguide (12) comprises: a first branch waveguide (121), and a second branch waveguide (122) extending from the first branch waveguide (121), wherein the second branch waveguide (122) is connected to the first branch waveguide (121) using the symmetrical splitting structure to separate a secondary optical signal of half the intensity from the optical signal at the current position, wherein the secondary optical signal is input to the corresponding intensity modulation unit, and the intensity modulation unit outputs the corresponding second optical signal.

3. The optical computing chip according to claim 2, characterized in that: The first waveguide further comprises: a primary branch waveguide extending from the row bus waveguide (11), wherein the primary branch waveguide is connected using a symmetrical optical splitting structure to separate a primary optical signal of half the intensity from an input optical signal at a current position.

4. The optical computing chip according to claim 1, wherein: The specific order of the third optical signal input into the second waveguide decreases sequentially along a first direction, and the width of the second waveguide decreases sequentially along the first direction, wherein the first direction is a direction opposite to a transmission direction of the optical signal in the second waveguide; And / or, the calculation unit is a photodetector; And / or, the first signal conversion unit is an asymmetric directional coupler.

5. The optical computing chip according to claim 1, wherein: The second waveguide is a multimode waveguide.

6. The optical computing chip according to claim 4 or 5, characterized in that: The branch waveguide comprises: at least two first sub-waveguides (31), a combining waveguide (32) connecting the at least two first sub-waveguides (31), and a second sub-waveguide (33) for transmitting a signal of the combining waveguide to the second waveguide; Correspondingly, the first waveguide includes: a first row of waveguides (41) arranged in sequence, and at least one middle row of waveguides (42) arranged in sequence; A plurality of first-row calculation units are provided on the first-row waveguide (41), and the first-row calculation units include: a beam splitter provided on the first-row waveguide (41), and a first sub-waveguide (31) connected through the beam splitter, an intensity modulation unit is provided on the first sub-waveguide (31), and an output end of the first sub-waveguide (31) is connected to the corresponding combining waveguide (32); The intermediate row waveguide (42) is provided with a plurality of intermediate row calculation units, and the intermediate row calculation units include: a beam splitter provided on the intermediate row waveguide (42), and a first sub-waveguide (31) connected through the beam splitter, the first sub-waveguide (31) is provided with an intensity modulation unit, and the first sub-waveguide is connected to the combined waveguide (32) through a second signal conversion unit, wherein different row waveguides use light of different wavelengths as the input optical signal, and the second signal conversion unit is used to combine at least two optical signals of different wavelengths into a beam of optical signals, and input the beam into the combined waveguide (32); The second sub-waveguide (33) is connected to the second waveguide via the first signal conversion portion.

7. The optical computing chip according to claim 6, characterized in that: The first waveguide is arranged in the first layer, the second waveguide is arranged in the second layer, and the first layer and the second layer are connected via the second sub-waveguide (33).

8. A design method for an optical computing chip according to claim 7, characterized in that: Including steps: S101, providing an optical computing chip, wherein the optical computing chip is provided with n first waveguides, and the first waveguides include: m traveling waveguides, the m traveling waveguides include: a first traveling waveguide and a middle traveling waveguides; and the m traveling waveguides are arranged at a first pitch; S102, setting at least one set of different test conditions, the test conditions including: a first set value of m, and a second set value of the first spacing; S103: Testing the optical computing chip according to at least one set of test conditions, and correspondingly collecting at least one set of first test results, where the first test results include: calculation results output by m*n second waveguides; wherein the calculation result is the sum of the powers of the m*n optical signals output by the second waveguides, and the m traveling waveguides respectively use light of m different wavelengths as input optical signals; S104, selecting at least one second test result that satisfies a first rule from the first test results, wherein the first rule requires that a ratio of differences in the calculated results be less than a set composite threshold and greater than a set reference number, where the ratio of differences is |calculated result - standard result| / standard result; S105, calculating at least one evaluation index L of the second test result according to the corresponding test condition, where L=αX+βY; wherein X is a first relative index of the first set value, Y is a second relative index of the second set value, α is a first weight, and β is a second weight; wherein the numerical value of the first set value is divided into at least two levels from small to large, and each level corresponds to a relative value for describing the first relative index; wherein the numerical value of the second set value is divided into at least two levels from small to large, and each level corresponds to a relative value for describing the second relative index; S106: Recommend corresponding test conditions to the user according to the evaluation index L as a preferred design solution.

9. The method for designing an optical computing chip according to claim 8, wherein: An order difference between two third optical signals coupled into the second waveguide is greater than a set order threshold, and the test condition further comprises: a third set value for the order difference; the value of the third set value is divided into at least two levels from small to large, and each level corresponds to a relative value for describing a third relative index of the third set value; The evaluation index L is: L=αX+βY+γZ1, γ is the third weight, and Z1 is the third relative index.

10. The method for designing an optical computing chip according to claim 8, wherein: The test condition further includes: a fifth set value of n; the value of the fifth set value is divided into at least two levels from small to large, and the levels correspond to a relative value for describing a fifth relative index of the fifth set value; Correspondingly, the evaluation index L is: L=αX+βY+εZ3; Wherein, ε is the fifth weight, and Z3 is the fifth relative index.

Images