Semiconductor optical nonlinear operation device, modulation method, and operation device

Abstract

The application relates to the technical field of semiconductor optical chips, in particular to a semiconductor optical nonlinear operation device, a modulation method and an operation device, which comprise a waveguide, a P-type semiconductor and an N-type semiconductor, wherein the P-type semiconductor and the N-type semiconductor are respectively doped on two sides of the waveguide to form a PN junction; when a reverse bias voltage value applied on the PN junction is greater than a preset threshold value, the waveguide is in an avalanche critical state, the waveguide absorbs incident light to generate a photoelectric current to trigger avalanche, plasma is generated in the waveguide, and the refractive index of the waveguide is changed based on nonlinear effects such as plasma dispersion effect or thermal effect, so that nonlinear modulation of light intensity is realized. Therefore, the problems of low nonlinear coefficient, poor scalability, high power consumption, small application range and weak light nonlinear in the related art are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor optical chips, in particular to a semiconductor optical nonlinear operation device, a modulation method and an operation device. BACKGROUND

[0002] The high-speed iteration of artificial intelligence algorithms makes the computing power and energy efficiency of traditional computing hardware gradually unable to meet the demand, and it is urgent to develop new computing chip to support artificial intelligence algorithms. A new technology trend internationally is to use light as a computing carrier, to design and process reasonable dielectric material structures, to make light achieve restricted propagation in line with the characteristics of artificial intelligence algorithms, and to complete the calculation.

[0003] Current optical intelligent computing includes resonant neural network, interference neural network, scattering neural network and diffraction neural network computing architecture, and these methods can complete the weighted summation process of neurons in artificial intelligence algorithms at high speed and high energy efficiency. However, the ability to express neuron nonlinear activation is limited, which limits the application of optical neural network chips.

[0004] In related technologies, the nonlinear layer is mainly borne by a photodetector linear array, and the photodetector reads the optical field energy output by the optical neural network, which is the square of the corresponding electric field intensity, to complete the square nonlinear calculation. This method has a low nonlinear coefficient, and can only add a nonlinear layer at the end of the network, and has poor scalability; in addition, the implementation of nonlinearity also includes the use of nonlinear materials to exhibit high-order nonlinear effects under high-energy light excitation, but this method has high energy consumption. SUMMARY

[0005] The present application provides a semiconductor optical nonlinear operation device, a modulation method and an operation device to solve the problems of low nonlinear coefficient, poor scalability, high power consumption, small application range and weak light nonlinear in related technologies.

[0006] The first aspect of the present application provides a semiconductor optical nonlinear operation device, comprising: a waveguide, a P-type semiconductor and an N-type semiconductor, wherein the P-type semiconductor and the N-type semiconductor are doped on both sides of the waveguide to form a PN junction, wherein when the reverse bias voltage value applied on the PN junction is greater than a preset threshold value, the waveguide is in an avalanche critical state, the waveguide absorbs incident light to generate a photo current to trigger an avalanche, an plasma is generated in the waveguide, and the refractive index of the waveguide is changed based on plasma dispersion effect or thermal effect to realize nonlinear modulation of light intensity.

[0007] Optionally, the waveguide is a ring waveguide structure or a Bragg resonant waveguide structure.

[0008] Optionally, the refractive index of the waveguide and the concentration of the plasma are in a first preset proportional relationship.

[0009] Optionally, the actual intensity of the avalanche triggered by the photoelectric current generated by the waveguide absorbing the incident light and the intensity of the incident light are in a second preset proportional relationship.

[0010] Optionally, when the refractive index of the waveguide is changed based on the plasma dispersion effect or the thermal effect, the resonance wavelength of the micro-ring oscillator is shifted, and the change degree of the light intensity of a preset wavelength near the resonance peak is greater than a preset degree.

[0011] The second aspect of the present application provides a nonlinear operator, which includes at least one semiconductor optical nonlinear operation device as described in the above embodiments.

[0012] The third aspect of the present application provides a modulation method of the semiconductor optical nonlinear operation device as described in the above embodiments, which includes the following steps: applying a reverse bias voltage value to the PN junction; when the reverse bias voltage value applied to the PN junction is greater than a preset threshold value, the waveguide is in an avalanche critical state, the waveguide absorbs the incident light to generate a photoelectric current to trigger an avalanche, a plasma is generated in the waveguide, the refractive index of the waveguide is changed based on the plasma dispersion effect or the thermal effect, and nonlinear modulation of the light intensity is realized.

[0013] Optionally, the changing of the refractive index of the waveguide based on the plasma dispersion effect or the thermal effect includes: obtaining an actual concentration of the plasma; and changing the refractive index of the waveguide to a target refractive index matched with the actual concentration according to the actual concentration of the plasma.

[0014] Optionally, the refractive index of the waveguide and the concentration of the plasma are in a first preset proportional relationship.

[0015] Optionally, the actual intensity of the avalanche triggered by the photoelectric current generated by the waveguide absorbing the incident light and the intensity of the incident light are in a second preset proportional relationship.

[0016] The present application has at least the following beneficial effects:

[0017] The embodiments of the present application have the characteristics of small size, low power consumption, and high modulation efficiency, and have the advantages of being compatible with the current silicon-based optoelectronic technology, and the like. The avalanche effect when a reverse bias voltage is applied to the PN junction is used to realize nonlinear modulation of the carrier concentration, the change of the refractive index of the silicon waveguide is realized based on the plasma dispersion effect or the thermal effect, and thus the nonlinear expression of the light intensity under weak light conditions on the chip is realized. Therefore, the problems of low nonlinear coefficient, poor scalability, high power consumption, small application range, and weak light nonlinear in the related art are solved.

[0018] Additional aspects and advantages of the present application will be made apparent by the following description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and / or additional aspects and advantages of the present application will become apparent and be more readily understood through consideration of the following description, taken in conjunction with the accompanying drawings, in which:

[0020] Figure 1 A schematic diagram of a device on chip for realizing nonlinear regulation of light intensity by using avalanche effect and plasma dispersion effect or thermal effect according to an embodiment of the present application;

[0021] Figure 2 A flowchart of a modulation method of a semiconductor optical nonlinear operation device according to an embodiment of the present application. DETAILED DESCRIPTION

[0022] Embodiments of the present application are described below in detail with reference to examples thereof illustrated in the accompanying drawings, in which like or similar elements and / or aspects with the same or similar functions and / or properties are designated by the same reference numerals throughout the drawings and the following description. The embodiments described below are examples for explaining the present application and are not intended to be limiting of the present application.

[0023] A semiconductor optical nonlinear operation device, a modulation method and an operation device according to embodiments of the present application are described below with reference to the accompanying drawings. In view of the problems of low nonlinear coefficient, poor scalability, high power consumption, small application range and weak light nonlinear in the background art, the present application provides a semiconductor optical nonlinear operation device, which is p+ and n+ doped on both sides of a ridge waveguide to form a PN junction. When a reverse bias voltage is applied and the voltage intensity reaches a certain threshold, avalanche effect occurs. When light is incident, photo-generated carriers trigger avalanche to rapidly increase the carrier concentration. Based on plasma dispersion effect or thermal effect, the refractive index of the ring waveguide changes greatly, which causes the resonance wavelength of the micro-ring oscillator to shift. Then, the light intensity of a specific wavelength near the resonance peak changes greatly. Under the premise of different light intensities, the transmittance is different, thereby realizing nonlinear modulation of intensity. Thus, the problems of low nonlinear coefficient, poor scalability, high power consumption, small application range and weak light nonlinear in the related art are solved.

[0024] Specifically, Figure 1 A schematic diagram of a device on chip for realizing nonlinear regulation of light intensity by using avalanche effect and plasma dispersion effect or thermal effect according to an embodiment of the present application.

[0025] As Figure 1 shown, the semiconductor optical nonlinear operation device includes a waveguide, a P-type semiconductor and an N-type semiconductor.

[0026] The P-type semiconductor and the N-type semiconductor are doped on two sides of the waveguide respectively to form a PN junction, and when a reverse bias voltage applied on the PN junction is greater than a preset threshold value, the waveguide is in an avalanche critical state, the waveguide absorbs incident light to generate a photo current to trigger an avalanche, a plasma is generated in the waveguide, and the refractive index of the waveguide is changed based on a plasma dispersion effect or a thermal effect to realize nonlinear modulation of light intensity.

[0027] The preset threshold value can be controlled according to semiconductor material selection, doping concentration, PN junction manufacturing process, etc., and can be from several volts to several thousand volts, which is adjusted and set according to specific conditions, and is not specifically limited here.

[0028] The avalanche refers to that when a semiconductor diode is applied with a high enough reverse bias, a carrier moving in a depletion layer can obtain avalanche multiplication due to collision ionization effect,

[0029] It can be understood that the P-type semiconductor and the N-type semiconductor are doped on two sides of the waveguide respectively to form a PN junction in the embodiment of the application, and when a reverse bias voltage applied on the PN junction is greater than a certain value, the waveguide is in an avalanche critical state, the waveguide absorbs incident light to trigger an avalanche to make the concentration of carriers rise sharply, a large number of electron-hole pairs are generated in the waveguide, and based on the principle of plasma dispersion effect, the refractive index of the ring waveguide changes greatly, which causes the resonance wavelength of the micro-ring oscillator to shift, and then the light intensity of a specific wavelength near the resonance peak changes greatly, thereby realizing nonlinear modulation of intensity.

[0030] In the embodiment of the application, the waveguide can be a ring waveguide or a Bragg resonant waveguide structure.

[0031] It can be understood that the waveguide in the embodiment of the application is a ring waveguide or a Bragg resonant waveguide structure, which has the characteristics of small size, low power consumption, and high modulation efficiency.

[0032] In the embodiment of the application, the refractive index of the waveguide and the concentration of the plasma have a first preset proportional relationship.

[0033] The first preset proportional relationship can be a proportional relationship between the refractive index of the waveguide and the concentration of the plasma, and when the concentration of the plasma is greater, the refractive index of the waveguide is also greater, which is not specifically limited here.

[0034] It can be understood that the greater the concentration of the plasma is, the greater the refractive index of the waveguide is in the embodiment of the application, and the change of the refractive index is realized through coupling of incident light and the plasma, thereby laying a foundation for weak light nonlinear effect and realizing nonlinear modulation of intensity.

[0035] In the embodiment of the present application, the actual intensity of the avalanche triggered by the photoelectric current generated by the waveguide absorbing the incident light is in a second preset proportional relationship with the intensity of the incident light.

[0036] The second preset proportional relationship can be a proportional relationship between the actual intensity of the avalanche triggered by the photoelectric current generated by the waveguide absorbing the incident light and the intensity of the incident light, and the stronger the incident light, the stronger the avalanche triggered by the incident light, which is not limited herein.

[0037] It can be understood that the stronger the incident light, the stronger the avalanche triggered by the incident light, and the nonlinear effect of amplifying weak light by using the semiconductor avalanche principle is used to realize the nonlinear modulation of intensity.

[0038] In the embodiment of the present application, when the refractive index of the waveguide is changed based on the plasmonic dispersion effect or thermal effect, the resonance wavelength of the micro-ring oscillator is shifted, and the change degree of the light intensity of the preset wavelength near the resonance peak is greater than the preset degree.

[0039] The preset wavelength can be adjusted and set according to actual conditions, because the same frequency wave propagates at different speeds in different media, and the wavelength is also different, for example, mechanical waves can be measured from their wavelengths, and audible sound wavelengths range from 17 mm to 17 m, which is not limited herein.

[0040] The preset degree can be a degree set by the user in advance, for example, the change degree of the light intensity near the resonance peak is greater than 50% or 60% set, which is not limited herein.

[0041] According to the semiconductor optical nonlinear operation device provided in the embodiment of the present application, the p+ and n+ doping is performed on both sides of the ridge waveguide to form a PN junction, the avalanche effect occurs when a reverse bias voltage is applied and the voltage intensity reaches a certain threshold, when light is incident, the photo-generated carrier triggers the avalanche to make the carrier concentration rise rapidly, based on the plasmonic dispersion effect or thermal effect, the refractive index of the ring waveguide changes greatly, which causes the resonance wavelength of the micro-ring oscillator to shift, and then the light intensity of a specific wavelength near the resonance peak changes greatly, under the premise that the light intensity is different, the transmittance is different, thereby realizing the nonlinear modulation of intensity. Thus, the problems of low nonlinear coefficient, poor scalability, high power consumption, small application range, and weak light nonlinear in the related art are solved.

[0042] The embodiment of the present application also provides a nonlinear operation device, which comprises the semiconductor optical nonlinear operation device as described above, so as to realize the nonlinear modulation of intensity.

[0043] Secondly, the modulation method of the semiconductor optical nonlinear operation device provided in the embodiment of the present application is described with reference to the accompanying drawings.

[0044] Figure 2A flowchart of a modulation method of a semiconductor optical nonlinear operation device according to an embodiment of the present application.

[0045] As shown in the figure, the modulation method of the semiconductor optical nonlinear operation device comprises the following steps: Figure 2

[0046] In step S101, a reverse bias voltage value is applied to the PN junction.

[0047] The PN junction is formed due to the diffusion movement of carriers caused by the difference in the concentration of electrons and holes, until the diffusion movement reaches an equilibrium state, forming a PN junction, in which an internal electric field is formed, pointing from the N region to the P region.

[0048] It can be understood that if a reverse voltage is applied to the PN junction, i.e., the P region is connected to -, and the N region is connected to +, the external electric field of the PN junction is the same as the internal electric field, the electric field force of the internal electric field hindering the movement of electrons is enhanced, the diffusion movement is further weakened, and the internal electric field is enlarged.

[0049] In step S102, when the reverse bias voltage value applied to the PN junction is greater than a preset threshold value, the waveguide is in an avalanche critical state, the waveguide absorbs incident light to generate a photoelectric current to trigger an avalanche, a plasma is generated in the waveguide, the refractive index of the waveguide is changed based on the plasma dispersion effect or thermal effect, and nonlinear modulation of light intensity is achieved.

[0050] It can be understood that when the reverse bias voltage applied to the PN junction is greater than a certain value, the waveguide is in an avalanche critical state, and when the waveguide absorbs incident light to trigger an avalanche, the concentration of carriers rises sharply, a large number of electron-hole pairs are generated in the waveguide, and based on the principle of plasma dispersion effect, the refractive index of the ring waveguide changes greatly, thereby achieving nonlinear modulation of intensity.

[0051] In the embodiment of the present application, changing the refractive index of the waveguide based on the plasma dispersion effect or thermal effect comprises: obtaining an actual concentration of the plasma; and changing the refractive index of the waveguide to a target refractive index matched with the actual concentration according to the actual concentration of the plasma.

[0052] It can be understood that the actual concentration of the plasma is obtained, the refractive index of the waveguide is changed to a refractive index matched with the actual concentration, and thereby nonlinear modulation of intensity is achieved.

[0053] In the embodiment of the present application, the refractive index of the waveguide and the concentration of the plasma have a first preset proportional relationship.

[0054] In the embodiment of the present application, the actual intensity of the photoelectric current triggering the avalanche generated by the waveguide absorbing the incident light has a second preset proportional relationship with the intensity of the incident light.

[0055] ​It should be noted that the foregoing description of the semiconductor optical nonlinear operation device embodiment also applies to the modulation method of the semiconductor optical nonlinear operation device of the embodiment, which will not be described here again.

[0056] According to the modulation method of the semiconductor optical nonlinear operation device provided in the embodiments of the present application, p+ and n+ doping is performed on both sides of the ridge waveguide to form a PN junction, avalanche effect occurs when a reverse bias voltage is applied and the voltage intensity reaches a certain threshold, when light is incident, photo-generated carriers trigger avalanche to rapidly increase the carrier concentration, based on the plasmonic dispersion effect or thermal effect, the refractive index of the ring waveguide changes greatly, which causes the resonance wavelength of the micro-ring oscillator to shift, and then the light intensity of a specific wavelength near the resonance peak changes greatly, and under the premise of different light intensities, the transmittance is different, thereby realizing nonlinear modulation of the intensity. Thus, the problems of low nonlinear coefficient, poor scalability, high power consumption, small application range, and weak light nonlinear in the related art are solved.

[0057] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0058] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "N" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0059] Any process or method descriptions in flow charts or otherwise described herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for implementing specific logic functions (or steps) in the process, and the various embodiments of the present application include additional implementations in which the order of steps can differ from those shown or discussed, including a step can occur at substantially the same time with other steps or can be performed in reverse order, depending upon the functionality involved. Such variations are within the scope of the present application.

[0060] It should be understood that portions of the application can be implemented in hardware, software, firmware, or combinations thereof. In the above embodiments, the N steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. As such, if implemented in hardware, and in another embodiment, any of the following technologies, known in the art, or their combinations, can be used to implement: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays, field programmable gate arrays, and the like.

[0061] Those skilled in the art can understand that all or part of the steps carried out by the above-mentioned embodiment methods can be completed by programs instructing related hardware, and the programs can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

Claims

1. A semiconductor optical nonlinear operation device, characterized by comprising: a semiconductor optical waveguide; and a semiconductor optical nonlinear operation layer provided on the semiconductor optical waveguide, wherein the semiconductor optical nonlinear operation layer is formed of a material having a nonlinear optical property. The semiconductor optical nonlinear operation device comprises a waveguide, a P-type semiconductor and an N-type semiconductor, wherein the P-type semiconductor and the N-type semiconductor are respectively doped on two sides of the waveguide to form a PN junction, and wherein when a reverse bias voltage applied on the PN junction is greater than a preset threshold value, the waveguide is in an avalanche critical state, the waveguide absorbs incident light to generate a photoelectric current to trigger an avalanche, plasma is generated in the waveguide, and the refractive index of the waveguide is changed based on a plasma dispersion effect or a thermal effect to achieve nonlinear modulation of light intensity; the waveguide is a ring waveguide structure; when the refractive index of the waveguide is changed based on the plasma dispersion effect or the thermal effect, the resonance wavelength of the micro-ring oscillator is shifted, and the change degree of the light intensity of a preset wavelength near the resonance peak is greater than a preset degree. The refractive index of the waveguide and the concentration of the plasma are in a first preset proportional relationship.

2. The semiconductor optical nonlinear operation device according to claim 1, wherein The actual intensity of the photoelectric current triggered by the avalanche of the waveguide absorbing the incident light and the intensity of the incident light are in a second preset proportional relationship.

3. The semiconductor optical nonlinear operation device according to claim 1, wherein The semiconductor optical nonlinear operation device comprises at least one semiconductor optical nonlinear operation device as claimed in any one of claims 1 to 3.

4. A non-linear operator characterized by, 5. A modulation method of a semiconductor optical nonlinear operation device as claimed in any one of claims 1 to 3, comprising the following steps: applying a reverse bias voltage on the PN junction; when the reverse bias voltage applied on the PN junction is greater than a preset threshold value, the waveguide is in an avalanche critical state, the waveguide absorbs incident light to generate a photoelectric current to trigger an avalanche, plasma is generated in the waveguide, and the refractive index of the waveguide is changed based on a plasma dispersion effect or a thermal effect to achieve nonlinear modulation of light intensity; the waveguide is a ring waveguide structure; when the refractive index of the waveguide is changed based on the plasma dispersion effect or the thermal effect, the resonance wavelength of the micro-ring oscillator is shifted, and the change degree of the light intensity of a preset wavelength near the resonance peak is greater than a preset degree. The changing of the refractive index of the waveguide based on the plasma dispersion effect or the thermal effect comprises:

6. The method of claim 5, wherein, obtaining an actual concentration of the plasma; changing the refractive index of the waveguide to a target refractive index matched with the actual concentration according to the actual concentration of the plasma. The refractive index of the waveguide and the concentration of the plasma are in a first preset proportional relationship.

7. The method of claim 6, wherein, The actual intensity of the photoelectric current triggered by the avalanche of the waveguide absorbing the incident light and the intensity of the incident light are in a second preset proportional relationship.

8. The method of claim 5, wherein, ​

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