Optical calculation module and optical calculation array based on germanium absorption layer

Abstract

The invention belongs to the technical field, and particularly relates to an optical calculation module and an optical calculation array based on a germanium absorption layer, and the optical calculation module comprises an input optical waveguide and an electric bus which are arranged in a crossed manner, and the input end of the input optical waveguide is provided with an optical splitter; the optical computing unit comprises an optical splitter, the output end of the optical splitter is connected with the first input end of a photoelectric signal processing unit through a transmission optical waveguide, and the output end of the photoelectric signal processing unit is connected with the electric bus. According to the invention, rapid conversion from unmodulated optical signals to electric signals can be realized, the size of the detector basically remains unchanged compared with the size of a detector device in the prior art, so that the size of a single optical calculation unit is smaller, a larger-scale matrix is realized compared with an existing scheme, the problem of difficult wiring of an existing discrete device is avoided, and the reliability of the detector is improved. The service life of the device is the same as that of a conventional silicon-based device, and the requirement for frequent switching of training levels can be met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor optoelectronic devices, and particularly relates to a light computing module based on a germanium absorption layer and a light computing array. BACKGROUND

[0002] Light computing technology has become an important research direction for breaking through the limitations of traditional computing due to its high parallelism, low latency, and potential high energy efficiency. However, existing light computing schemes still have significant challenges in device structure, power consumption, and trainability, which limit their application in large-scale computing and training tasks.

[0003] Currently, the core structure of a light computing unit is usually based on a combination of a modulator and a detector, where the modulator is responsible for encoding or computing operations on optical signals, and the detector completes photoelectric conversion. This discrete design makes it difficult to further optimize the area and power consumption of a single computing unit, which in turn limits the integration scale and energy efficiency of the light computing chip. Specifically, the above-mentioned discrete prior art scheme has the following limitations: 1. Light computing architecture based on phase change material (for example, the applicant's prior application document CN118394171B): the switching speed of the phase change material is limited, which is difficult to meet the demand of high-frequency weight update in training tasks; and when frequently switched, the dynamic power consumption will increase significantly, resulting in a decrease in overall energy efficiency.

[0004] 2. Light computing architecture based on carrier absorption (for example, prior art CN109960310A): its power consumption is high, mainly due to the carrier injection loss when the modulator is forward biased, and the combination of discrete modulators and detectors further increases the unit area, limiting the integration density.

[0005] That is, the above-mentioned discrete design scheme is limited in size and has high power consumption.

[0006] Therefore, there is an urgent need for a light computing unit that can meet the requirements of high-frequency switching, low power consumption, and large-scale integration while ensuring computing accuracy. SUMMARY

[0007] The purpose of the present application is to provide a light computing module based on a germanium absorption layer and a light computing array to partially alleviate or solve the above-mentioned deficiencies and meet the requirements of high-frequency switching, low power consumption, and large-scale integration.

[0008] In order to solve the above-mentioned technical problems, the present application specifically adopts the following technical solutions: The first aspect of the present application is to provide a light computing module based on a germanium absorption layer, comprising: The input optical waveguide and the electric bus are cross arranged, the input end of the input optical waveguide is provided with a light splitter, the output end of the light splitter is connected with the first input end of an optoelectronic signal processing unit through a transmission optical waveguide, and the electric output end of the optoelectronic signal processing unit is connected with the electric bus; The photoelectric characteristic of the light absorption layer in the optoelectronic signal processing unit can be changed by a control signal inputted through the second input end, the optoelectronic signal processing unit can convert the optical signal inputted through the first input end into a corresponding electric current signal, and the electric current signal is sent to the electric bus through the electric output end; the photoelectric characteristic includes the light absorption coefficient of the light absorption layer; The product of the multiplier value and the multiplicand value is encoded in the electric current signal; The optoelectronic signal processing unit comprises a silicon substrate and an insulating layer deposited on the silicon substrate; the insulating layer is provided with a waveguide layer; and the waveguide layer is embedded with a germanium absorption layer.

[0009] As an improvement, the optoelectronic signal processing unit uses pure germanium as the light absorption layer; The first depth of embedding the germanium absorption layer in the waveguide layer is greater than the thickness of the waveguide layer.

[0010] As an improvement, the top and / or bottom of the germanium absorption layer is provided with a heating unit, and the heating unit extends along the length direction of the germanium absorption layer; or, The two sides of the germanium absorption layer are respectively provided with a heating unit, and the heating unit extends along the length direction of the germanium absorption layer; or, The two sides of the germanium absorption layer are respectively provided with a heating unit group, and each side of the heating unit group comprises a plurality of heating units uniformly spaced along the length direction of the germanium absorption layer, wherein the heating levels of the adjacent two heating units on the same side are first heating and second heating respectively.

[0011] As an improvement, the germanium absorption layer comprises a light guiding region and a light absorption region arranged in sequence along the light propagation direction, The cross-sectional area of the light guiding region gradually increases along the direction close to the light absorption region from the incident end; and the cross-sectional area of the light absorption region is the same along the light propagation direction.

[0012] As an improvement, the width of the light guiding region gradually increases along the light propagation direction when viewed from the top; and the width of the light guiding region gradually decreases from the top to the bottom when viewed from the side; or, the interface between the light guiding region and the waveguide layer is fan-shaped; and / or, the light absorption region is rectangular when viewed from the side.

[0013] The second aspect of the present application provides a germanium absorption layer-based optical computing array, comprising: A crossbar switch matrix architecture formed by a plurality of rows of input optical waveguides and a plurality of columns of electrical buses crossing each other; optical input signals are transmitted through the input optical waveguides; A plurality of optical splitters arranged at the front end of each intersection node of a row of optical input waveguides and a column of electrical buses; A plurality of optoelectronic signal processing units, each corresponding to an intersection node, and a first input end of the optoelectronic signal processing unit is connected to an output end of the optical splitter through a transmission optical waveguide, and an electrical output end of the optoelectronic signal processing unit is connected to the electrical bus in the corresponding intersection node; Wherein, the optoelectronic properties of the optical absorption layer in the optoelectronic signal processing unit can be changed by a write control signal input through the second input end, and the optoelectronic signal processing unit can convert the optical signal input through the first input end into a corresponding current signal and send it to the electrical bus through the electrical output end; the optoelectronic properties include the optical absorption coefficient; wherein the product of the multiplier value and the multiplicand value is encoded in the current signal; The optoelectronic signal processing unit includes a silicon substrate and an insulating layer deposited on the silicon substrate; the insulating layer is provided with a waveguide layer; the waveguide layer is embedded with a germanium absorption layer.

[0014] As an improvement, the optoelectronic signal processing unit uses pure germanium as the optical absorption layer; the first depth of the germanium absorption layer embedded in the waveguide layer is greater than the thickness of the waveguide layer.

[0015] As an improvement, the top and / or bottom of the germanium absorption layer is provided with a heating unit extending along the length direction of the germanium absorption layer; or, the two sides of the germanium absorption layer are respectively provided with a heating unit extending along the length direction of the germanium absorption layer; or, the two sides of the germanium absorption layer are respectively provided with a heating unit group, and each side of the heating unit group includes a plurality of heating units uniformly spaced along the length direction of the germanium absorption layer, wherein the heating levels of the adjacent two heating units on the same side are first heating and second heating respectively.

[0016] As an improvement, the germanium absorption layer includes a light guiding region and an absorption region arranged in sequence along the light propagation direction, wherein the cross-sectional area of the light guiding region gradually increases from the incident end along the direction close to the light absorption region; the cross-sectional area of the light absorption region is the same along the light propagation direction.

[0017] As an improvement, the second input end of each optoelectronic signal processing unit is connected to a Pad, and each column of electrical buses is provided with a Pad; and / or, each row of input optical waveguides is provided with an EOM.

[0018] The principles and beneficial technical effects of the present application are that: The present application adopts independent photoelectric signal processing units to realize modulation and detection simultaneously. Specifically, the optical signal input into the photoelectric signal processing unit is not modulated and is a stable value. When the optical signal is processed by the photoelectric signal processing unit, the absorbed part of the optical signal is directly converted into a current signal as output for summation operation, without the need to separately convert the unabsorbed optical signal (i.e. the remaining optical signal) into an electrical signal by a detector. Moreover, the size of the photoelectric signal processing unit remains basically unchanged compared with the size of the detector in the prior art, which can make the size of a single optical computing module smaller, thereby realizing a larger scale matrix compared with the prior art, and avoiding the problems of difficult wiring and large size caused by the discrete structure of modulator + detector in the prior art (the discrete structure first modulates the optical signal by a modulator, and then converts the modulated optical signal into an electrical signal by a detector), which is not conducive to large-scale integration. In addition, the service life of the photoelectric signal processing unit in the present application is the same as that of the conventional silicon-based device, which can meet the frequent switching requirements of the training level. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without any creative labor.

[0020] Figure 1 is a side view structural schematic diagram of the prior art; Figure 2 is a side view structural schematic diagram of the fourth embodiment of the present application; Figure 3 is a top view structural schematic diagram of the fourth embodiment of the present application; Figure 4 is a top view of the gradual section in the fourth embodiment of the present application; Figure 5 is an exemplary side view of the modulator in the third embodiment of the present application; Figure 6 is another exemplary side view of the modulator in the third embodiment of the present application; Figure 7 is still another exemplary side view of the modulator in the third embodiment of the present application; Figure 8 is a top view of the modulator in the third embodiment of the present application; Figure 9 is a front view of the germanium absorption layer in embodiment three and the germanium ribbon in embodiment four of the present application; Figure 10 is a top view of the germanium absorption layer in embodiment three and the germanium ribbon in embodiment four of the present application; Figure 11 is a schematic diagram of the light computing module in embodiment one of the present application; Figure 12 is a schematic diagram of the light computing array in embodiment two of the present application; Figure 13 is a schematic diagram of another light computing array in embodiment two of the present application; Figure 14 is a schematic diagram of yet another light computing array in embodiment two of the present application; Figure 15 is a schematic diagram of the light computing module in embodiment five of the present application; Figure 16 is a schematic diagram of the signal comparison by the detection unit in embodiments five to seven of the present application; Figure 17 is a flow chart of the detection method in embodiment seven of the present application.

[0021] Marked in the figure: 1, silicon substrate; 2, insulating layer; 3, ridge type optical waveguide / waveguide layer; 31, silicon ridge; 32, flat plate layer; 4, electrode; 5, germanium ribbon / germanium absorption layer; 51, gradual section / light guiding area; 52, straight section / light absorbing area; 6, silicon ribbon; 7, heating unit; 101, photoelectric signal processing unit; 102, input optical waveguide; 103, transmission optical waveguide; 104, transmission optical waveguide; 105, optical splitter. DETAILED DESCRIPTION

[0022] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0023] Herein, the suffix such as "module", "part", or "unit" used for representing an element is only for facilitating the description of the present application, and has no specific meaning by itself. Therefore, "module", "part", or "unit" can be mixedly used. Herein, the terms "upper", "lower", "inner", "outer", "front", "back", "one end", "the other end", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for facilitating the description of the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0024] Herein, unless otherwise explicitly specified and limited, the terms "mount", "provided with", "connected", and the like should be broadly understood, for example, "connected" can be fixedly connected, or detachably connected, or integrally connected; can be mechanically connected, can be directly connected, or indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. Herein, "a plurality of" means two or more, that is, it includes two, three, four, five, etc.

[0025] Herein, the "optical splitter" can utilize components such as optical waveguide, optical coupler, heater, phase shifter, etc. with specific structure to realize the distribution of optical signals inside the chip in an active or passive manner.

[0026] Herein, Pad is used for transmitting electrical signals or optical signals in the optical computing unit or the electrical bus; EMO is an optical modulator based on electro-optic effect, which controls the power, phase and polarization of laser beam through electronic control signal, and is used for preliminary modulation of input optical signal, so as to provide the optical signal processing unit with optical signal conforming to its processing range.

[0027] Embodiment one The embodiment provides an optical computing unit, comprising: The input optical waveguide and the electrical bus are cross-connected, the input end of the input optical waveguide is provided with an optical splitter, the output end of the optical splitter is connected with the first input end of an optoelectronic signal processing unit through a transmission optical waveguide, and the electrical output end of the optoelectronic signal processing unit is connected with the electrical bus.

[0028] The photoelectric characteristics of the light absorption layer in the photoelectric signal processing unit can be changed by a control signal input through the second input end, and the photoelectric signal processing unit can convert the light signal input through the first input end into a corresponding current signal and send it to the electrical bus through the electrical output end. The product of the multiplier value and the multiplicand value is encoded in the current signal.

[0029] The prior art optical computing unit uses a combination of discrete modulators and detectors. Part of the light signal in the input modulator is absorbed, and the remaining light signal is output from the light output end of the modulator and enters the detector to be converted into an electrical signal, which is then processed in the data terminal. The optical computing unit in the present application is completely different from the above scheme. It uses an independent photoelectric signal processing unit that directly converts the absorbed part of the light signal into an electrical signal as output for summation and other operations and then inputs it into the backend data terminal for data processing, without the need for additional processing of the remaining light signal, thereby directly obtaining the processed electrical signal.

[0030] The size of the photoelectric signal processing unit in the present scheme remains basically unchanged compared to the size of the detector device in the prior art, thereby enabling a smaller size of the individual optical computing unit, realizing a larger scale matrix compared to the prior art, and avoiding the wiring difficulty problem of the prior discrete devices. The service life performance is the same as that of conventional silicon-based devices, and it can meet the frequent switching requirements of the training level.

[0031] Embodiment Two The present embodiment provides an optical computing array comprising a plurality of optical computing modules as in Embodiment One, comprising: A crossbar switch matrix architecture formed by a plurality of rows of parallel input optical waveguides and a plurality of columns of parallel electrical buses intersecting each other; an optical input signal is transmitted through the input optical waveguides; A plurality of optical splitters arranged at the front end of each intersection node of each row of optical input waveguides and each column of electrical buses; A plurality of photoelectric signal processing units, each corresponding to one of the intersection nodes, and the first input end of the photoelectric signal processing unit is connected to the output end of the optical splitter through the transmission optical waveguide, and the electrical output end of the photoelectric signal processing unit is connected to the electrical bus in the corresponding intersection node; The photoelectric characteristics of the light absorption layer in the photoelectric signal processing unit can be changed by a control signal input through the second input end, and the photoelectric signal processing unit can convert the light signal input through the first input end into a corresponding current signal and send it to the electrical bus through the electrical output end. The photoelectric characteristics include the light absorption coefficient. wherein a product of the multiplier value and the multiplicand value is encoded in the current signal.

[0032] In some embodiments, a second input end of each of the photoelectric signal processing units is connected to a Pad, and a Pad is arranged on each column of the electric bus; and / or, an EOM is arranged on each row of the input optical waveguide.

[0033] Embodiment Three The present embodiment provides a photoelectric signal processing unit, which uses pure germanium as a light absorption layer, as an example of the photoelectric signal processing unit in Embodiment One and / or Embodiment Two: The photoelectric signal processing unit comprises a silicon substrate and an insulating layer deposited on the silicon substrate; a waveguide layer is arranged on the insulating layer; a germanium absorption layer is embedded in the waveguide layer; a first depth at which the germanium absorption layer is embedded in the waveguide layer is less than a thickness of the waveguide layer (in this case, “shallow etching”), or a second depth at which the germanium absorption layer is embedded in the waveguide layer is equal to the thickness of the waveguide layer (in this case, “full etching”).

[0034] In the above embodiments, when the second depth is equal to the thickness of the waveguide layer 3, i.e., the insulating layer 2 is taken as the etching endpoint, on the one hand, the germanium absorption layer 5 can have a larger cross section, so that the light field overlaps with the modulation region for the longest time. In the same length, the responsivity is higher; in the same responsivity, the size is the smallest. On the other hand, the etching depth is easy to control, which can ensure the consistency of the etching groove depth between different modulators. In the traditional shallow etching process, due to the shallow etching depth and the difficulty in accurate control, the etching depth is easily affected by factors such as uneven silicon layer thickness, resulting in inconsistent etching depth, which further affects the performance uniformity of the modulator. The etching groove process that reaches the insulating layer 2 has better stability, which is conducive to large-scale production of high-quality modulators.

[0035] In some embodiments, the first depth of the waveguide layer can also be greater than the thickness of the waveguide layer, in which case it is “over-etching”.

[0036] In some embodiments, at least one side of the germanium absorption layer 5 is provided with a heating unit 7.

[0037] In some specific embodiments, heating units 7 are provided at the top and / or bottom of the germanium absorption layer 5, and the heating units 7 extend along the length direction of the germanium absorption layer 5; or, heating units 7 are provided on both sides of the germanium absorption layer 5, and the heating units 7 extend along the length direction of the germanium absorption layer 5; or, heating unit groups 7 are provided on both sides of the germanium absorption layer 5, and each side of the heating unit group 7 includes a plurality of heating units 7 evenly spaced along the length direction of the germanium absorption layer 5, wherein the heating levels of two adjacent heating units 7 on the same side are primary heating and secondary heating, respectively; the heating units 7 are used to change the photoelectric properties of the light absorption layer.

[0038] Unlike the traditional approach of relying on high electric field strength to increase the absorption coefficient and thus ensure the uniformity of photocurrent density, this invention provides a thermal compensation mechanism that only addresses the endpoint effect. Specifically, by setting a heating unit 7 on at least one side (bottom and / or top, or front and back sides) of the germanium absorption layer 5, the heating unit 7 acts on the germanium absorption layer 5 along the length of the germanium absorption layer, ensuring the consistency and uniformity of the temperature of the entire germanium absorption layer 5, thereby increasing the number of valence band electrons that can jump, thereby changing the light absorption coefficient of the germanium absorption layer 5 while reducing the operating voltage of the electroabsorption modulator. In this process, it is only necessary to ensure the final light absorption rate (i.e., the ratio of input light to output light / input light), without considering the uniformity of the light absorption coefficient of the germanium absorption layer 5.

[0039] In other words, this application provides a thermal compensation mechanism that dually regulates the light absorption coefficient, targeting only the endpoint effect. First, the light absorption coefficient of the germanium absorption layer is adjusted from the germanium modulator itself by heating the germanium absorption layer. Then, the light absorption coefficient of the germanium absorption layer is further adjusted by adjusting the input voltage. That is to say, the adjustment requirements of the input voltage in this process are not high. In other words, the response speed of the computing array can be guaranteed while ensuring low energy consumption, thereby meeting the requirements of large-scale matrices.

[0040] In some embodiments, the germanium modulator further includes: A temperature monitoring module is used to monitor the actual temperature value of the germanium absorption layer 5 in real time.

[0041] The first judgment module is used to determine whether the actual temperature value monitored by the temperature monitoring module is greater than a first preset temperature threshold. If the actual temperature value is greater than the first preset temperature threshold, a first control signal indicating that heating has stopped is generated and sent to the heating unit 7 / the heating unit group; if the actual temperature value is less than the first preset temperature threshold, a second control signal indicating that monitoring continues is generated and sent to the temperature monitoring module; and / or, A temperature monitoring module is configured to monitor the actual temperature value of the germanium absorption layer 5 in real time after the heating unit 7 in the heating level of one and in the heating state is heated.

[0042] A second judging module is configured to judge whether the actual temperature value monitored by the temperature monitoring module reaches a preset target temperature threshold value within a preset time length, and if not, generate and send a third control signal representing the heating unit 7 in the heating level of two and in the dormant state is started, so that the actual temperature of the germanium absorption layer 5 reaches the preset target temperature threshold value.

[0043] The first temperature threshold value can be obtained by a large number of experiments in advance, or be preset by the user according to experience. When the actual temperature is near the first preset temperature threshold value, the number of transitionable valence band electrons tends to be maximized, but at the same time, the material itself will not be adversely affected.

[0044] The division of heating levels (one and two) is only to distinguish between the two, and cannot limit the heating power or other characteristics. In the case of only starting one heating, the heating power is small, and when one and two heating are started at the same time, the heating power increases, and the temperature of the germanium absorption layer 5 can also be correspondingly increased.

[0045] The present application can maximize the number of transitionable valence band electrons as much as possible, and on the other hand, can improve the stability of the temperature of the germanium absorption layer 5, and prevent the problem that the light signal emitted by the germanium absorption layer 5 is unstable due to frequent changes in the temperature of the germanium absorption layer 5.

[0046] In some embodiments, the germanium absorption layer includes a light guiding region and a light absorbing region arranged in sequence along the light propagation direction, wherein the cross-sectional area of the light guiding region gradually increases from the incident end along the direction close to the light absorbing region; the cross-sectional area of the light absorbing region is the same along the light propagation direction.

[0047] In some specific embodiments, the longitudinal section of the light guiding region 51 is a right trapezoid, and the included angle a between the hypotenuse of the right trapezoid corresponding to the interface between the light guiding region 51 and the waveguide layer 3 and the bottom side is 86°-89°; the longitudinal section of the light absorbing region 52 is a rectangle; or the interface between the light guiding region 51 and the waveguide layer 3 is a sector. Wherein, the longitudinal section refers to the vertical plane parallel to the length direction of the germanium absorption layer.

[0048] The width of the light guiding region gradually increases from the incident end along the light propagation direction in a plan view, and the width of the light guiding region gradually decreases from the top to the bottom in a side view, or the interface between the light guiding region and the waveguide layer is in a sector shape, and / or the cross section of the light absorbing region is in a rectangular shape.

[0049] The purpose of the above arrangement is to achieve a smooth transition of the refractive index, because the refractive index of silicon is about 3.4, and the refractive index of germanium is about 4.4. By gradually changing the structure, the refractive index gradually transitions from the waveguide layer 3 (silicon waveguide) to germanium, reducing the reflection of light at the incident end. When light propagates at the interface of different refractive index media, the greater the difference in refractive index, the more serious the reflection. This gradual transition structure allows light to enter the germanium absorbing layer 5 more smoothly from the silicon waveguide, improves the coupling efficiency of light, and thus improves the light absorption capacity of the modulator.

[0050] In an ideal case, the light guiding region is a cone shape with a small front and a large back, and the conical structure can achieve a more perfect refractive index gradient, minimizing the reflection of light when entering the germanium absorbing layer 5, and theoretically maximizing the coupling efficiency of light.

[0051] Due to process limitations, the conical light guiding region requires high cost. Therefore, in order to reduce the process difficulty in this embodiment, only the cross-sectional area of the light guiding region gradually increases from the incident end along the direction close to the light absorbing region 52, for example, the light guiding region is a triangle with a narrow front and a wide back in a plan view, and a trapezoid with a large top and a small bottom in a side view. Although it is different from the ideal conical shape, the trapezoidal structure still achieves a certain degree of refractive index gradient and reduces light reflection, which is a feasible solution under the existing process conditions.

[0052] That is, by limiting the shape of the light guiding region, the cross-sectional area of the light guiding region gradually increases in height and length from the incident end, which can greatly reduce the reflection of light at the incident end when propagating in the light absorbing layer (germanium absorbing layer) with a larger cross-sectional area, and improve the light absorption rate of the modulator. That is, the present application provides a full etching scheme with a thermal compensation mechanism that can reduce light reflection.

[0053] In some embodiments, the width and length of the heating unit 7 located at the top and / or bottom of the germanium absorbing layer 5 are smaller than the width and length of the germanium absorbing layer 5. In this way, the heating effect is ensured while unnecessary heat waste is avoided.

[0054] In summary, for the millisecond-level frequent switching requirement in the deep learning training scene, the present application provides a high-response light computing module / computing array with a thermal compensation mechanism that can reduce light reflection, to realize the design of a low-power large-scale integrated computing array under the condition of meeting the frequent switching.

[0055] In contrast to the existing modulation using phase change material, or changing the light absorption coefficient by injecting current or applying voltage to change the carrier concentration in the doping, the present application provides a light computing array based on a reverse-biased germanium modulator, while the light absorption characteristics of the germanium absorption layer are multiple regulated.

[0056] Firstly, the photoelectric signal processing unit with a pure germanium absorption layer in the present application has extremely low dark current under reverse bias, and the photocurrent during operation is at least 2 orders of magnitude smaller than that of the carrier absorption modulator or the phase change material modulator under forward conduction, thereby effectively reducing the power consumption of the individual device during operation.

[0057] Further, a heating unit is provided on at least one side of the germanium absorption layer, and a real-time feedback mechanism is used to ensure the consistency and uniformity of the temperature of the entire germanium absorption layer, thereby increasing the transitionable valence band electrons, and changing the light absorption coefficient of the germanium absorption layer while reducing the operating voltage of the photoelectric signal processing unit.

[0058] Further, in the case of a large light absorption cross-sectional area of the light absorption region (germanium absorption layer) (for example, "full etching"), the present application designs the germanium absorption layer in a partitioned manner (light guiding region and light absorption region), and uses the gradually changing interface formed by the gradual change in the height and width of the light guiding region to guide the light signal transmitted from the optical waveguide, that is, to make the cross-sectional area of the light guiding region gradually increase in height and length from the incident end, thereby greatly reducing the reflection of light at the incident end when the light propagates in the larger cross-sectional area of the light absorption layer (germanium absorption layer), and improving the light absorption rate of the photoelectric signal processing unit.

[0059] Embodiment Four The present embodiment provides a photoelectric signal processing unit, which uses pure germanium as a light absorption layer, and differs from Embodiment Three in that: The photoelectric signal processing unit comprises a silicon substrate 1 and an insulating layer 2 deposited on the silicon substrate 1; the insulating layer 2 is provided with an optical waveguide; the optical waveguide is provided with an etching groove reaching the insulating layer 2 or an etching groove embedded in the insulating layer 2; the etching groove is filled with a germanium strip 5 as a light absorption region, and electrodes 4 are provided on both sides of the etching groove.

[0060] The bottom of the germanium strip 5 is flush with the upper surface of the insulating layer 2, or the bottom of the germanium strip 5 is embedded in the insulating layer 2, and the top of the germanium strip 5 protrudes from the upper surface of the optical waveguide.

[0061] In the present embodiment, compared with Figure 1The prior art shallow etching of the optical waveguide reaches the insulating layer 2, i.e. the bottom of the etching groove is flush with the upper surface of the insulating layer 2 or embedded in the insulating layer 2. The bottom of the germanium strip 5 in the etching groove can be flush with the upper surface of the insulating layer 2 or the bottom of the germanium strip 5 is embedded in the insulating layer 2 while the top of the germanium strip 5 can protrude from the upper surface of the optical waveguide. The germanium strip 5 has a larger cross section so that the light field coincides with the detection area for the longest time. With the same length, the responsivity is higher; with the same responsivity, the size is smaller.

[0062] In addition, the insulating layer 2 is used as the etching end point, the etching depth is easy to control, and the consistency of the etching groove depth between different detectors can be ensured. In the conventional shallow etching process, the etching depth is shallow and difficult to accurately control, and is easily affected by factors such as uneven silicon layer thickness, resulting in inconsistent etching depth and affecting the performance uniformity of the detector. The etching groove process reaching the insulating layer has better stability, which is conducive to large-scale production of high-quality detectors.

[0063] More specifically, the optical waveguide in the embodiment is a ridge optical waveguide 3, which includes a flat plate layer 32 and a silicon ridge 31 on the flat plate layer 32; the electrode 4 is arranged on the flat plate layer 32; and the etching groove penetrates the silicon ridge 31.

[0064] The ridge optical waveguide 3 utilizes the propagation characteristics of light in different refractive index media. The refractive index of the silicon ridge 31 is higher than that of the surrounding environment, forming a constraint on light. When light propagates in the ridge optical waveguide, it is confined to the region of the silicon ridge 31, reducing light scattering and loss and improving light transmission efficiency, providing a stable light transmission channel for the light detection process of the detector.

[0065] The electrode 4 is arranged on the flat plate layer 32, which is convenient for connection with external circuits. The flat plate layer 32 provides a larger planar area, which is conducive to the manufacture and layout of the electrode 4 and can ensure good electrical contact between the electrode 4 and external circuits. At the same time, this layout avoids direct interference of the electrode 4 with the light propagation path, reduces the absorption or scattering of light in the propagation process due to the presence of the electrode, and ensures stable transmission of the optical signal in the silicon ridge, improving the light detection performance of the detector.

[0066] The etching groove penetrates the silicon ridge 31, providing sufficient space for the filling of the germanium strip 5. The germanium strip 5 serves as a light absorption area and is in close contact with the light propagation path. When light propagates in the ridge optical waveguide, it passes through the germanium strip 5 in the etching groove, which can fully absorb the light signal and convert it into an electrical signal. The design of the etching groove penetrating the silicon ridge 31 ensures sufficient interaction between light and the germanium strip 5, enhances the light absorption effect, and thus improves the responsivity of the detector and enhances the detection sensitivity of the detector to the optical signal.

[0067] As shown in FIG. 1, the detector includes a substrate 1, an optical waveguide 3, an electrode 4 and a germanium strip 5. Figure 3As shown, in some embodiments, the germanium strip 5 is connected with a silicon strip 6 at both ends. Figure 4 As shown, the germanium strip 5 includes a progressive section 51 (also referred to as a light guiding region herein) and a straight section 52 (also referred to as a light absorbing region herein); the progressive section 51 is arranged at the incident end of the germanium strip 5, and the cross-sectional area of the progressive section 51 increases along the light incident direction (i.e. the light propagation direction); the shape of the exit end of the silicon strip 6 is matched with the progressive section 51.

[0068] The above arrangement aims to achieve a smooth transition of the refractive index, because the refractive index of silicon is about 3.4 and the refractive index of germanium is about 4.4. By changing the structure in this way, the refractive index can gradually transition from the silicon waveguide to the germanium, reducing the reflection of light at the incident end. When light propagates at the interface of different refractive index media, the greater the difference in refractive index, the more serious the reflection. This progressive transition structure enables the light to enter the germanium strip more smoothly from the silicon waveguide, improves the coupling efficiency of the light, and further improves the light absorption capability of the detector.

[0069] In an ideal case, the progressive section 51 is a circular cone with a small front and a large back, and the circular cone structure can achieve a more perfect refractive index gradient, minimizing the reflection of light when entering the germanium strip, and theoretically maximizing the coupling efficiency of light and the responsivity of the detector.

[0070] Due to process limitations, the progressive section 51 in the form of a circular cone requires high cost. Therefore, in order to reduce the process difficulty, the progressive section 51 in this embodiment is a triangle with a narrow front and a wide back when viewed from above and a trapezoid with a large top and a small bottom when viewed from the front, as shown in Figure 4 、 Figure 5 Although it is different from the ideal circular cone, the trapezoidal structure still enables a certain degree of refractive index gradient and reduces light reflection, which is a feasible solution under the existing process conditions. More preferably, the length of the progressive section 51 along the light propagation direction is the same as the length of the straight section 52 along the light propagation direction.

[0071] In some other embodiments, a silicon-germanium alloy transition layer is arranged between the incident end of the germanium strip 5 and the silicon strip 6, and the silicon-germanium alloy transition layer is gradiently doped with the germanium concentration increasing from the silicon strip side to the germanium strip side. The germanium concentration increases from 10% on the silicon strip side to 100% on the germanium strip side. By arranging the silicon-germanium alloy transition layer with the germanium concentration increasing from 10% on the silicon strip 6 side to 100% on the germanium strip side, the refractive index can gradually transition from the refractive index of silicon to the refractive index of germanium. In the transition layer, the refractive index gradually increases with the increase of the germanium concentration, forming a refractive index gradient region between the silicon strip and the germanium strip. In this way, the reflection caused by the sudden change of the refractive index is reduced during the light propagation, and the light can enter the germanium strip more smoothly from the silicon strip, improving the coupling efficiency of the light.

[0072] In addition, the electrode 4 in the embodiment is a metal electrode made of copper or aluminum. Copper and aluminum have good processing performance in the semiconductor manufacturing process. They can be deposited by various common process methods, such as sputtering in physical vapor deposition (PVD), electron beam evaporation, etc., to form the required electrode pattern. In the photolithography and etching process, the shape and size of the electrode can also be accurately defined to meet the design requirements of the detector. Moreover, these materials are widely used in industrial production, and the related process equipment and technology are mature, which is convenient for mass production and reduces production costs.

[0073] The application improves the responsivity of the photoelectric signal processing unit by increasing the light absorption area, while realizing the miniaturization of the device, thereby facilitating large-scale integration. Specifically, the etching groove is etched on the waveguide in a full etching or over-etching manner, thereby increasing the light absorption area (i.e., the cross-sectional area) along the light propagation direction, and further improving the light absorption rate, significantly improving the responsivity of the photoelectric signal processing unit, so that it can better meet the demand for high-sensitivity detection of optical signals, and also does not need to increase the length of the germanium band, which is more conducive to the miniaturization of the device.

[0074] In addition, the application improves the poor process stability. In the prior art shallow etching, on the one hand, the process itself cannot be completely consistent every time, and on the other hand, the slight difference in the thickness of the silicon layer can cause different etching depths, affecting the consistency of the performance indicators such as the dark current and the responsivity of the photoelectric signal processing unit. In the application, the etching groove reaches the insulating layer, and the insulating layer is used as a stable etching stop layer, which greatly reduces the sensitivity of the process to the change in the thickness of the silicon layer, improves the process stability, and makes the performance of the produced photoelectric signal processing unit more stable and uniform.

[0075] The application avoids the performance loss caused by light leakage. In the traditional shallow etching structure, when the light propagates in the germanium / silicon processing area, it is easy to leak to the bottom of the shallow etching groove, reducing the overlap time of the light field and the germanium, and affecting the processing efficiency. The design of the etching groove reaching the insulating layer in the application optimizes the light propagation path, reduces light leakage, ensures the full action of the light field and the germanium band, and improves the comprehensive performance of the photoelectric signal processing unit.

[0076] In addition, the application increases the light absorption area from the cross-sectional view, so that when the light is incident to the interface between the germanium band and the silicon, the amount of reflected light will also increase. Therefore, in the application, the gradual structure change of the silicon band and the germanium band can gradually transition the refractive index from the silicon waveguide to the germanium, reducing the reflection of the light at the incident end. When the light propagates at the interface of different refractive index media, the greater the difference in refractive index, the more serious the reflection. This gradual transition structure can make the light enter the germanium band from the silicon waveguide more smoothly, improve the coupling efficiency of the light, and further improve the absorption capacity of the detector to the light.

[0077] Embodiment five The embodiment provides an optical computing module with a self-detection function, referring to Figure 15 , comprising: The input optical waveguide and the output electrical bus are cross arranged, the input end of the input optical waveguide is provided with a light splitter, the output end of the light splitter is connected with the first input end of an optoelectronic signal processing unit through a transmission optical waveguide, and the optoelectronic signal processing unit is further provided with a second input end for inputting an external electrical driving signal; The electrical output end of the optoelectronic signal processing unit is connected with the electrical bus; The optical output end of the optoelectronic signal processing unit is connected with a detection unit, and the detection unit comprises a detector and a data processing unit connected in sequence; The optical input end of the detector is connected with the optical output end of the optoelectronic signal processor, the data processing unit is provided with a first input end for inputting the electrical driving signal, and the second input end of the data processing unit is connected with the electrical output end of the detector.

[0078] The data processing unit is used for analyzing the electrical driving signal and the output electrical signal output by the detector to obtain an analysis result, and the data processing unit can be an upper computer.

[0079] The first input end of the optoelectronic signal processing unit is an optical input end, and the second input end is an electrical input end; the optical signal entering the optoelectronic signal processing unit through the optical input end is modulated by the electrical driving signal input through the electrical input end, the part of the optical signal absorbed is converted into an electrical signal and output to the electrical bus, and the other part of the optical signal (the remaining optical signal) not absorbed is conducted to the optical output end and enters the detector in the detection unit.

[0080] In some embodiments, the detection unit further comprises a comparator, the comparator is arranged between the detection unit and the detector, the comparator is provided with a first input end for inputting the electrical driving signal, the second input end of the comparator is connected with the electrical output end of the detector, and the output end of the comparator is connected with the data processing unit.

[0081] Therefore, the optical computing module with the independent detection unit is provided, the residual optical signal in the optical computing module is used to directly generate the output electrical signal corresponding to the residual optical signal, and then the output electrical signal is synchronously output to the external correction unit for comparison, so that the distortion between the two is directly obtained. Compared with the prior art of inserting error correction codes in the calculation data signal to improve the calculation accuracy, the application is improved from the hardware structure. On the one hand, the cost is low, and the calculation amount is small. On the other hand, the residual optical signal (instead of the output electrical signal) is used for error correction, and the entire error correction process is independent, which does not affect other components or signals in the detection unit of the optical computing module.

[0082] In some embodiments, the photoelectric signal processing unit can be the photoelectric signal processing unit in Embodiment Three, specifically, the photoelectric signal processing unit comprises: a silicon substrate and an insulating layer deposited on the silicon substrate; the insulating layer is provided with a waveguide layer; the waveguide layer is embedded with a germanium absorption layer; the first depth of the germanium absorption layer embedded in the waveguide layer is less than the thickness of the waveguide layer, or the second depth of the germanium absorption layer embedded in the waveguide layer is equal to the thickness of the waveguide layer.

[0083] The top and / or bottom of the germanium absorption layer is provided with a heating unit, and the heating unit extends along the length direction of the germanium absorption layer; or the two sides of the germanium absorption layer are respectively provided with a heating unit, and the heating unit extends along the length direction of the germanium absorption layer; or the two sides of the germanium absorption layer are respectively provided with a heating unit group, and each side of the heating unit group comprises a plurality of heating units uniformly spaced along the length direction of the germanium absorption layer, wherein the heating levels of the adjacent two heating units on the same side are first heating and second heating respectively.

[0084] In summary, the application actually provides an error correction scheme for "amplifying" the residual optical signal and detecting it by using an independent detection unit.

[0085] In the application, the photoelectric signal processing unit is improved in structure, pure germanium is used as the absorption layer of the photoelectric signal processor, and a double-regulation thermal compensation mechanism for the light absorption coefficient is provided. Specifically, the light absorption coefficient of the germanium absorption layer is adjusted from the germanium modulator itself by heating the germanium absorption layer, and then the light absorption coefficient of the germanium absorption layer is further adjusted by adjusting the input voltage. The requirement for adjusting the input voltage is not high, that is, the response speed of the calculation module can be greatly improved under the condition of ensuring low energy consumption, in other words, the residual optical signal and the output electrical signal in the calculation module can be "amplified" to a certain extent.

[0086] Further, the remaining light signal is amplified, and the distortion of the amplified light signal is analyzed to avoid the case that the distortion is too small to be detected.

[0087] In some embodiments, the photoelectric signal processing unit can be the photoelectric signal processing unit in Embodiment Four, and specifically, the photoelectric signal processing unit comprises a silicon substrate and an insulating layer deposited on the silicon substrate; a waveguide layer (also referred to as an optical waveguide) is arranged on the insulating layer; an etching groove reaching the insulating layer or embedded in the insulating layer is formed on the waveguide layer; the etching groove is filled with a germanium absorption layer (also referred to as a germanium strip) as a light absorption region, and electrodes are arranged on both sides of the etching groove. The bottom of the germanium absorption layer is flush with the upper surface of the insulating layer, or the bottom of the germanium absorption layer is embedded in the insulating layer; and the top of the germanium absorption layer protrudes from the upper surface of the waveguide layer.

[0088] In some embodiments, the germanium absorption layer comprises a light guiding region and a light absorption region arranged in sequence along the light propagation direction, wherein the cross-sectional area of the light guiding region gradually increases from the incident end along the direction close to the light absorption region; and the cross-sectional area of the light absorption region is the same along the light propagation direction.

[0089] In some embodiments, the width of the light guiding region gradually increases from the incident end along the light propagation direction when viewed from the top; and the width of the light guiding region gradually decreases from the top to the bottom when viewed from the side; or the interface between the light guiding region and the waveguide layer is fan-shaped; and / or the light absorption region is rectangular when viewed from the side.

[0090] In summary, the present application also provides an error correction scheme for amplifying the remaining light signal and detecting the amplified light signal by using an independent detection unit.

[0091] Different from the above scheme, the photoelectric processing unit in the present scheme increases the light absorption area to improve the responsivity of the photoelectric signal processing unit, which can realize the miniaturization of the device, thereby facilitating the realization of large-scale integration.

[0092] Specifically, the present application adopts full etching or over-etching to etch grooves on the waveguide, thereby increasing the light absorption area (i.e. cross-sectional area) along the light propagation direction, and further improving the light absorption rate; meanwhile, the shape of the light guiding region is doubly limited from the length direction and the height direction, i.e. the cross-sectional area of the light guiding region gradually increases from the incident end in terms of height and length, which can greatly reduce the reflection of light at the incident end when the light propagates in the light absorption layer (germanium absorption layer) with a larger cross-sectional area, and improve the light absorption rate of the optoelectronic signal processing unit, i.e. the remaining optical signal and the output electrical signal in the calculation module can also be "amplified" to a certain extent.

[0093] Further, the "amplified" remaining optical signal is used for error correction analysis, which can obtain the "amplified" distortion condition, and further avoid the case that the distortion degree is small and difficult to detect.

[0094] Embodiment six The present embodiment provides an optical computing array with self-detection function, which includes a plurality of optical computing modules as described in embodiment five. Specifically, the optical computing array includes: a crossbar switch matrix architecture formed by a plurality of rows of parallel input optical waveguides and a plurality of columns of parallel electrical buses; an optical input signal is transmitted through the input optical waveguide; a plurality of optical splitters, which are arranged at the front end of each intersection node of each row of optical input waveguides and each column of electrical buses; a plurality of optoelectronic signal processing units, each of which corresponds to one of the intersection nodes, and the first input end of the optoelectronic signal processing unit is connected to the output end of the optical splitter through the transmission optical waveguide, and the second input end of the optoelectronic signal processing unit is also provided for inputting an external electrical driving signal; the electrical output end of the optoelectronic signal processing unit is connected to the electrical bus in the corresponding intersection node; the optical output end of the optoelectronic signal processing unit is connected with a detection unit, which includes a detector and a data processing unit connected in sequence; wherein the optical input end of the detector is connected to the electrical output end of the optoelectronic signal processor, and the first input end of the data processing unit is provided for inputting the electrical driving signal, and the second input end of the data processing unit is connected to the electrical output end of the detector.

[0095] In some embodiments, the optoelectronic signal processing unit is also provided with a third input end for inputting a reference voltage, which is used to provide a reference voltage value for the electrical output end, so that the electrical output end can induce a current signal according to the reference voltage value, and the current signal can flow to a specified direction to be collected, thereby realizing summation operation.

[0096] For example, refer to Figure 11 The reference voltage can be 2V (volts), when the voltage value at the electrical output end is less than 2V, the current signal flows in the first direction a; when the voltage value at the electrical output end is greater than 2V, the current signal flows in the second direction b; wherein the first direction a and the second direction b are opposite, the current signals flowing in the same direction converge at the end of the electrical bus.

[0097] In some embodiments, the photoelectric signal processing unit comprises: a silicon substrate and an insulating layer deposited on the silicon substrate; a waveguide layer is arranged on the insulating layer; a germanium absorption layer is embedded in the waveguide layer; the first depth of the germanium absorption layer embedded in the waveguide layer is less than the thickness of the waveguide layer, or the second depth of the germanium absorption layer embedded in the waveguide layer is equal to the thickness of the waveguide layer; The top and / or bottom of the germanium absorption layer is provided with a heating unit, which extends along the length direction of the germanium absorption layer; or, The two sides of the germanium absorption layer are respectively provided with a heating unit, which extends along the length direction of the germanium absorption layer; or, The two sides of the germanium absorption layer are respectively provided with a heating unit group, and each side of the heating unit group comprises a plurality of heating units uniformly spaced along the length direction of the germanium absorption layer, wherein the heating levels of the adjacent two heating units on the same side are respectively first heating and second heating.

[0098] In some embodiments, the germanium absorption layer comprises a light guiding region and a light absorbing region arranged in sequence along the light propagation direction, Wherein, the cross-sectional area of the light guiding region gradually increases along the direction close to the light absorbing region; the cross-sectional area of the light absorbing region is the same along the light propagation direction.

[0099] Embodiment seven The embodiment provides a detection method of an optical computing module, referring to Figures 15-17 Based on the optical computing module in embodiment five or the optical computing array in embodiment six, comprising the following steps: S1, obtaining an electrical driving signal input into the photoelectric signal processing unit and an output electrical signal output by the detector; S2, synchronously inputting the electrical driving signal and the output electrical signal into a data processing unit to obtain an electrical signal difference value in the current state; S3, repeatedly executing steps S1 and S2 to obtain a plurality of electrical signal difference values; S4, calculating a plurality of signal mean values according to the plurality of electrical signal difference values; S5, judging whether the signal mean value conforms to the preset signal range, if yes, marking the optical computing module as normal, otherwise marking the optical computing module as abnormal.

[0100] The preset signal range is input by a user in advance or obtained from a large number of experiments in advance and stored in the data processing unit. When the signal mean value does not conform to the preset signal range, it indicates that the signal is distorted, and at this time, artificial judgment is introduced. The abnormality is caused by signal distortion of the signal source, or a problem of the device, or an abnormality caused by other conditions.

[0101] The above detection method can avoid the "misjudgment" problem caused by signal delay by detecting multiple electrical signal differences and analyzing the multiple electrical signal differences.

[0102] In some embodiments, the detection method is based on the optical computing module in Embodiment Five or the optical computing array in Embodiment Six, and includes the following steps: S1, obtaining an electrical modulation signal S1 input into the optoelectronic signal processing unit and an output electrical signal I1 output by the detector.

[0103] S2, synchronously inputting the electrical modulation signal S1 and the output electrical signal I1 into the data processing unit and calculating an electrical signal difference between the electrical modulation signal S1 and the output electrical signal I1; wherein the difference has a constant relationship with a current signal O1 output by the optoelectronic signal processing unit, and deviation from the constant can be determined as signal packet loss in the optoelectronic signal processing unit.

[0104] S3, inputting the electrical signal difference into the data processing unit and judging whether the electrical signal difference conforms to a preset difference value range, if yes, marking the optical computing module as normal, otherwise marking the optical computing module as abnormal.

[0105] Referring to Figure 16 , a signal comparison diagram of normal signals and abnormal signals is provided in the figure, wherein the abscissa t is time and the ordinate P is power.

[0106] It should be noted that in this paper, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0107] The embodiments of the present application are described above with reference to the accompanying drawings, but the present application is not limited to the above-described specific embodiments, and the above-described specific embodiments are merely illustrative, but not restrictive, and a person of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, and these all belong to the protection of the present application.

Claims

1. A germanium-absorbing layer-based optical computing module, characterized by, The application relates to a cross-over switch matrix architecture, which is formed by a plurality of rows of parallel input optical waveguides and a plurality of columns of parallel electrical buses. The photoelectric characteristic of a light-absorbing layer in the photoelectric signal processing unit can be changed by a control signal inputted through a second input end, and the photoelectric signal processing unit can convert an optical signal inputted through a first input end into a corresponding current signal and send the current signal to the electrical bus through an electrical output end; the photoelectric characteristic includes a light absorption coefficient of the light-absorbing layer. A product of a multiplier value and a multiplicand value is encoded in the current signal. The photoelectric signal processing unit comprises a silicon substrate and an insulating layer deposited on the silicon substrate; a waveguide layer is arranged on the insulating layer; and a germanium absorbing layer is embedded in the waveguide layer as the light-absorbing layer. The photoelectric signal processing unit uses pure germanium as the light-absorbing layer.

2. The germanium-absorbing-layer-based optical computing module according to claim 1, wherein, The first depth of embedding the germanium absorbing layer in the waveguide layer is greater than the thickness of the waveguide layer. A heating unit is arranged on the top and / or bottom of the germanium absorbing layer, and the heating unit extends along the length direction of the germanium absorbing layer; or 3. The germanium-absorbing-layer-based optical computing module of claim 2, wherein, A heating unit is arranged on each side of the germanium absorbing layer, and the heating unit extends along the length direction of the germanium absorbing layer; or A heating unit group is arranged on each side of the germanium absorbing layer, and each heating unit group comprises a plurality of heating units which are uniformly and spacedly arranged along the length direction of the germanium absorbing layer, wherein the heating levels of two adjacent heating units on the same side are first heating and second heating respectively. The germanium absorbing layer comprises a light-guiding region and a light-absorbing region which are arranged in sequence along the light propagation direction.

4. The germanium-absorbing-layer-based optical computing module of claim 2, wherein, The cross-sectional area of the light-guiding region gradually increases from the incident end along the direction close to the light-absorbing region; and the cross-sectional area of the light-absorbing region is the same along the light propagation direction. The width of the light-guiding region gradually increases from the incident end along the light propagation direction when viewed from the top; and the width of the light-guiding region gradually decreases from the top to the bottom when viewed from the side; or the interface between the light-guiding region and the waveguide layer is fan-shaped; and / or the light-absorbing region is rectangular when viewed from the side.

5. The germanium-absorbing-layer-based optical computing module of claim 4, wherein, The application relates to a cross-over switch matrix architecture, which is formed by a plurality of rows of parallel input optical waveguides and a plurality of columns of parallel electrical buses.

6. A germanium-absorbing layer based optical computing array, comprising: An optical input signal is transmitted through the input optical waveguide. A plurality of optical splitters are arranged at the front end of each cross node of each row of optical input waveguides and each column of electrical buses. A plurality of photoelectric signal processing units are arranged at the front end of each cross node of each row of optical input waveguides and each column of electrical buses. An optical input signal is transmitted through the input optical waveguide. A plurality of optical splitters are arranged at the front end of each cross node of each row of optical input waveguides and each column of electrical buses. A plurality of photoelectric signal processing units are arranged at the front end of each cross node of each row of optical input waveguides and each column of electrical buses. The photoelectric characteristic of the light absorption layer in the photoelectric signal processing unit can be changed by a second input end write control signal, and the photoelectric signal processing unit can convert the light signal input by the first input end into a corresponding current signal and send it to the electrical bus through the electrical output end; the photoelectric characteristic includes a light absorption coefficient; The product of the multiplier value and the multiplicand value is encoded in the current signal; The photoelectric signal processing unit includes a silicon substrate and an insulating layer deposited on the silicon substrate; the waveguide layer is arranged on the insulating layer; the germanium absorption layer is embedded in the waveguide layer.

7. The germanium-absorbing layer based optical computing array of claim 6, wherein, The photoelectric signal processing unit uses pure germanium as the light absorption layer; The first depth of the germanium absorption layer embedded in the waveguide layer is greater than the thickness of the waveguide layer.

8. The germanium-absorbing layer based optical computing array of claim 7, wherein, The top and / or bottom of the germanium absorption layer is provided with a heating unit, and the heating unit extends along the length direction of the germanium absorption layer; or, The two sides of the germanium absorption layer are respectively provided with a heating unit, and the heating unit extends along the length direction of the germanium absorption layer; or, The two sides of the germanium absorption layer are respectively provided with a heating unit group, and each side of the heating unit group includes a plurality of heating units uniformly spaced along the length direction of the germanium absorption layer, wherein the heating levels of the adjacent two heating units on the same side are first heating and second heating.

9. The germanium-absorbing layer based optical computing array of claim 7 or 8, wherein, The germanium absorption layer includes a light guiding region and an absorption region arranged in sequence along the light propagation direction, The cross-sectional area of the light guiding region gradually increases from the incident end along the direction close to the light absorption region; the cross-sectional area of the light absorption region is the same along the light propagation direction.

10. The germanium-absorbing layer based optical computing array of claim 7 or 8, wherein, The second input end of each photoelectric signal processing unit is connected to a Pad, and each column of electrical buses is provided with a Pad; and / or, each row of input light waveguides is provided with an EOM.

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