Logic operation system and method for simulating biological brain neuron dynamics

Abstract

The invention belongs to the technical field of neuromorphic photon calculation and spiking neural networks, and relates to a logical operation system and method for simulating biological brain neuron dynamics, and the system comprises an injection light module which is used for generating a first injection light signal and a second injection light signal; the input end of the light modulation module is connected with the output end of the injection light module, and the light modulation module is used for modulating and coupling the first injection light signal and the second injection light signal and outputting a coupling signal; the input end of the vertical cavity surface emitting laser is connected with the output end of the light modulation module, and the vertical cavity surface emitting laser is used for receiving the coupling signal and performing laser response on two paths of injection light signals in the coupling signal in the XP polarization direction and the YP polarization direction respectively to realize logic operation; and the input end of the output module is connected with the output end of the vertical cavity surface emitting laser, and the output module is used for outputting the laser response in a time sequence form to obtain a logic operation result. The logic operation system provided by the invention is simple in structure and relatively low in cost, and meanwhile, the operation rate reaches GHz.

Description

Technical Field

[0001] The present invention relates to the field of neuromorphic photonic computing and spike neural network technology, and in particular to a logic operation system that simulates biological brain neuron dynamics, an XOR operation method that simulates biological brain neuron dynamics, and a NOR operation method that simulates biological brain neuron dynamics. Background Art

[0002] Neuromorphic computing mainly abstracts human brain neurons from the perspective of information processing, and simulates the way biological brain neural networks process and memorize information by establishing corresponding neural computing models and systems. Spiking neural networks process information by simulating the structure and function of the brain. For example, when a spike neural network receives an external stimulus that reaches a threshold, it will respond in the form of a peak. The sparse spike sequence of its response contains information such as the time and intensity of the external stimulus. Compared with traditional neural networks, spike neural networks have the advantages of low power consumption and strong parallel processing capabilities, and therefore have attracted widespread attention.

[0003] As a typical excitable device, semiconductor lasers can achieve excitatory output under external disturbances, such as optical feedback, current modulation, light injection and mutual coupling. They have the advantages of simple structure, convenient operation and easy integration. Therefore, they are very suitable for simulating neurons in spiking neural networks, thereby constructing spiking neural networks.

[0004] In recent years, researchers have used photonic devices such as semiconductor lasers as neurons in spiking neural networks to construct spiking neural network systems that can perform functions such as logical operations, frequency coding, and pattern recognition. These constructed logical operation systems, frequency coding systems, and pattern recognition systems can efficiently process complex sensor data, and therefore have wide applications in fields such as autonomous driving, medical health, and industrial automation. In the prior art, a system for simulating neuron dynamics and realizing XOR logic operation using a vertical cavity surface emitting laser based on a dual-modulation light injection scheme, and a photon XOR logic operation system based on the carrier recovery characteristics of a vertical cavity surface optical amplifier have been proposed. These systems use two semiconductor lasers as the first input end and the second input end of the logic operation, modulate the input signals of the two semiconductor lasers respectively, and then use a photodetector in combination with the laser responses of the two semiconductor lasers to output an electrical signal representing the result of the logic operation, thereby realizing the XOR logic operation. Specifically, when the two semiconductor lasers both emit light under the stimulation of the input signal (that is, the output of the semiconductor laser is a high level), the photodetector receives two light signals at this time. Since the two light signals interfere with each other and cancel each other, the photodetector outputs an electrical signal representing a logic 0; when the two semiconductor lasers do not emit light (that is, the output of the semiconductor laser is a low level), the electrical detector does not receive the light signal at this time, and therefore outputs an electrical signal representing a logic 0; when the light emission states of the two semiconductor lasers are different, the photodetector receives an light signal, and thus outputs an electrical signal representing a logic 1. However, the logic operation system constructed using two semiconductor lasers is large in size. If it is applied to a large-scale spike neural network to achieve complex tasks, the size of the spike neural network will be further increased. At the same time, due to the difference in response time of different semiconductor lasers to input signals, this means that the two semiconductor lasers cannot reach a stable output state at the same time, that is, the two optical signals output by the two semiconductor lasers cannot reach the photodetector at the same time, resulting in the photodetector outputting an erroneous logic operation result. In order to minimize the impact of inconsistent signal timing on the accuracy of the operation results, it is usually necessary to add a delay line to adjust the timing of the signal, or use a complex calibration procedure to match the response time of the two lasers, resulting in the speed of the logic operation being limited to 200MHz, reducing the operation rate of the logic operation system, making the logic operation system unsuitable for application scenarios with high requirements for real-time data processing (for example: high-speed production line monitoring in industrial automation, real-time power scheduling in smart grids, etc.).

[0005] In summary, the logic operation system in the prior art that uses semiconductor lasers to simulate the dynamics of biological brain neurons has the problems of large size, low accuracy of operation results and low operation speed. Summary of the invention

[0006] To this end, the technical problem to be solved by the present invention is to overcome the problems of large size, low accuracy of calculation results and low calculation rate in the prior art logic operation system that uses semiconductor lasers to simulate the dynamics of biological brain neurons.

[0007] In order to solve the above technical problems, the present invention provides a logic operation system for simulating the dynamics of biological brain neurons, comprising: An injection optical module, used to generate a first injection optical signal and a second injection optical signal with tunable wavelengths; wherein the frequencies of the first injection optical signal and the second injection optical signal are both greater than or equal to the response frequency of the vertical cavity surface emitting laser; an optical modulation module, whose input end is connected to the output end of the injection optical module, and is used to modulate and couple the first injection optical signal and the second injection optical signal, and output a coupled signal; A vertical cavity surface emitting laser, whose input end is connected to the output end of the optical modulation module, is used to receive the coupling signal and perform laser response to two injection optical signals in the coupling signal in the XP polarization direction and the YP polarization direction respectively, so as to realize logic operation; The output module has an input end connected to the output end of the vertical cavity surface emitting laser and is used to output the laser response of the vertical cavity surface emitting laser in a time sequence form to obtain a logic operation result.

[0008] Preferably, the injection light module comprises: A first tunable laser, used to generate a first injection optical signal with tunable wavelength; The second tunable laser is used to generate a second injection optical signal with tunable wavelength.

[0009] Preferably, the optical modulation module comprises: A first arbitrary waveform generator, used to generate a first modulated electrical signal; a first Mach-Zehnder modulator, whose input end is connected to the output end of the first tunable laser and the output end of the first arbitrary waveform generator, and is used to modulate the first injected optical signal based on the first modulating electrical signal; A second arbitrary waveform generator, used to generate a second modulated electrical signal; a second Mach-Zehnder modulator, whose input end is connected to the output end of the second tunable laser and the output end of the second arbitrary waveform generator, and is used to modulate the second injected optical signal based on the second modulating electrical signal; The first optical coupler is used to couple the first injection optical signal and the second injection optical signal and output a coupled signal.

[0010] Preferably, the output module comprises: a photodetector, whose input end is connected to the output end of the vertical cavity surface emitting laser, and is used to convert the laser response of the vertical cavity surface emitting laser into an electrical signal; An oscilloscope, whose input end is connected to the output end of the photodetector, is used to output the electrical signal in a time sequence form.

[0011] Preferably, the output module further includes: An optical spectrum analyzer, whose input end is connected to the output end of the vertical cavity surface emitting laser, is used to obtain optical spectrum response data corresponding to the laser response of the vertical cavity surface emitting laser.

[0012] Preferably, the output module further includes: A second optical coupler, whose input end is connected to the output end of the vertical cavity surface emitting laser, whose first output end is connected to the input end of the photodetector, and whose second output end is connected to the input end of the spectrum analyzer, is used to divide the laser response of the vertical cavity surface emitting laser into a first laser response and a second laser response, and input the first laser response to the photodetector so that the photodetector converts the first laser response into an electrical signal, and input the second laser response to the spectrum analyzer so that the spectrum analyzer obtains spectrum response data corresponding to the second laser response.

[0013] The present invention also provides an XOR logic operation method for simulating biological brain neuron dynamics, the method is implemented using the above-mentioned logic operation system for simulating biological brain neuron dynamics, and includes: Using an injection optical module to generate a first injection optical signal and a second injection optical signal with tunable wavelengths; wherein the frequencies of the first injection optical signal and the second injection optical signal are both greater than or equal to the response frequency of the vertical cavity surface emitting laser; Using an optical modulation module to modulate and couple the first injected optical signal and the second injected optical signal respectively, adjusting the frequency of the first injected optical signal to a first preset range, and adjusting the frequency of the second injected optical signal to a second preset range, so that in the modulated first injected optical signal and the second injected optical signal, one injected optical signal is a high-level signal, and the other injected optical signal is a low-level signal, and outputting a coupled signal; The coupling signal is received by a vertical cavity surface emitting laser, and under the excitation of the two injection optical signals in the coupling signal before modulation, no peaks are generated in the XP polarization direction and the YP polarization direction, and under the excitation of the two injection optical signals in the coupling signal after modulation, a peak is generated in the XP polarization direction or the YP polarization direction, thereby realizing an exclusive OR logic operation; The output module is used to output the laser response of the vertical cavity surface emitting laser in a time sequence form to obtain an exclusive OR logic operation result.

[0014] Preferably, when the response frequency of the vertical cavity surface emitting laser is 20ns -1 hour, The first preset range is 0ns -1 ~5ns -1 , and the second preset range is 19ns -1 ~22ns -1 ;or, The first preset range is 19ns -1 ~21ns -1 , and the second preset range is 0ns -1 ~5.5ns -1 .

[0015] The present invention also provides a method for performing an OR-NOT operation for simulating the dynamics of biological brain neurons. The method is implemented using the above-mentioned logical operation system for simulating the dynamics of biological brain neurons, and comprises: Using an injection optical module to generate a first injection optical signal and a second injection optical signal with tunable wavelengths; wherein the frequencies of the first injection optical signal and the second injection optical signal are both greater than or equal to the response frequency of the vertical cavity surface emitting laser; Using an optical modulation module to modulate and couple the first injection optical signal and the second injection optical signal respectively, adjusting the frequency of the first injection optical signal to a third preset range, and adjusting the frequency of the second injection optical signal to a fourth preset range, so that the modulated first injection optical signal and the second injection optical signal are both low-level signals, and outputting a coupling signal; The coupling signal is received by a vertical cavity surface emitting laser, and under the excitation of the two injection optical signals in the coupling signal before modulation, no peaks are generated in the XP polarization direction and the YP polarization direction, and under the excitation of the two injection optical signals in the coupling signal after modulation, peaks are generated in the XP polarization direction and the YP polarization direction, thereby realizing a non-OR logic operation; The output module is used to output the laser response of the vertical cavity surface emitting laser in a time sequence form to obtain a logical NOR operation result.

[0016] Preferably, when the response frequency of the vertical cavity surface emitting laser is 20ns -1 When the third preset range is 10ns -1 ~18ns -1 , the fourth preset range is 6ns -1 ~10ns -1 .

[0017] The logic operation system simulating the dynamics of biological brain neurons provided by the present application has the following beneficial effects: 1. Based on the dual polarization characteristics of the vertical cavity surface emitting laser, the present application uses the two orthogonal polarization modes of the vertical cavity surface emitting laser as the first input end and the second input end of the logic operation. At the same time, the present application finds that by adjusting the frequencies of the two injected light signals in the coupling signal input to the vertical cavity surface emitting laser, the excitability threshold of the vertical cavity surface emitting laser can be changed, so that the vertical cavity surface emitting laser makes an excitation response to the two injected light signals in the coupling signal in the form of spikes in the XP polarization and YP polarization directions respectively. At the same time, its output excitation response is manifested as the result of a logic operation on the two signals in the coupling signal. Therefore, the present application uses two injection light signals generated by the injection light module to simulate the signal transmission between biological neurons, uses the optical modulation module to modulate and couple the injection light signals, generates a coupling signal that can change the excitability threshold of the vertical cavity surface emitting laser, and uses the vertical cavity surface emitting laser to simulate the biological neurons to respond to the coupling signal, thereby constructing a logic operation system that simulates the dynamics of biological brain neurons. Only one laser is needed to construct a dual-input single-output logic operation system, which has a simple structure, low cost, and reduces the system volume; at the same time, it avoids the influence of the response time difference of different semiconductor lasers on the accuracy of the operation results, and there is no need to match the timing of the two signals by extending the operation time, so that the logic operation rate of the entire system is increased to GHz, which greatly improves the efficiency of the logic operation, so that it can be used in various application scenarios with high requirements for real-time data processing. In addition, since the threshold current of the vertical cavity surface emitting laser is low, only a few milliamperes, not only the noise in the injected light signal is low, the accuracy of the logic operation is improved, but also the power consumption of the entire logic operation system is reduced.

[0018] 2. Based on the logic operation system for simulating the neuron dynamics of the biological brain provided by the present application, it is only necessary to use the optical modulation module to modulate and couple the first injection light signal and the second injection light signal, adjust the frequency of the first injection light signal to the first preset range, and adjust the frequency of the second injection light signal to the second preset range, so that in the modulated first injection light signal and the second injection light signal, one injection light signal is a high-level signal and the other injection light signal is a low-level signal, and the coupling signal is output. The vertical cavity surface emitting laser can generate no peaks in the XP polarization direction and the YP polarization direction under the excitation of the two injection light signals in the coupling signal before modulation, and generate peaks in the XP polarization direction or the YP polarization direction under the excitation of the two injection light signals in the coupling signal after modulation, thereby realizing exclusive OR logic operation.

[0019] 3. The OR-NOT logic operation needs to output a high-level signal when both inputs are low-level signals. For the traditional logic operation system constructed using two semiconductor lasers, it is necessary to make the entire system output a high-level signal when there is no input optical signal in the two semiconductor lasers. However, when there is no input optical signal, the semiconductor laser will not produce a spike-shaped excitation response, and the system cannot output a high-level signal. Therefore, due to the input and output characteristics of the semiconductor laser, the existing logic operation system constructed using semiconductor lasers cannot realize the OR-NOT logic operation. The logic operation system for simulating the neuron dynamics of a biological brain provided by the present application utilizes an optical modulation module to modulate and couple a first injection light signal and a second injection light signal, adjusts the frequency of the first injection light signal to a third preset range, and adjusts the frequency of the second injection light signal to a fourth preset range, so that the modulated first injection light signal and the second injection light signal are both low-level signals, and outputs a coupling signal. The vertical cavity surface emitting laser can generate no peaks in the XP polarization direction and the YP polarization direction under the excitation of the two injection light signals in the coupling signal before modulation, and can generate peaks in the XP polarization direction and the YP polarization direction under the excitation of the two injection light signals in the coupling signal after modulation, thereby realizing an OR-NOT logic operation and expanding the types of logic operations and the scope of tasks that can be realized by the logic operation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 A schematic diagram of the structure of a logical operation system for simulating biological brain neuron dynamics provided in this application; Figure 2 A flow chart of the XOR logic operation method for simulating biological brain neuron dynamics provided in this application; Figure 3 A flow chart of the OR-NOT logic operation method for simulating biological brain neuron dynamics provided in this application; Figure 4 A schematic diagram of biological neuron dynamics characteristics regarding dual-path light injection intensity simulated by a logic operation system simulating biological brain neuron dynamics provided in an embodiment of the present application; wherein, Figure 4 (a) is a schematic diagram of the activation peak response of the XP polarization and YP polarization modes to the coupled signal. Figure 4 (b) is the timing diagram of the output of the logic operation system when a peak response is generated only in the XP polarization direction. Figure 4 (c) is the timing diagram of the output of the logic operation system when a peak response is generated only in the YP polarization direction. Figure 4(d) is a timing diagram of the output of the logic operation system when a peak response is generated in both the XP polarization and the YP polarization directions; Figure 5 A schematic diagram of the operation result of an XOR logic operation based on neuron dynamics implemented by a logic operation system simulating biological brain neuron dynamics provided in an embodiment of the present application; wherein, Figure 5 (a) is a schematic diagram of the input and output intensity in the XP polarization direction. Figure 5 (b) is a schematic diagram of the input and output intensity in the YP polarization direction. Figure 5 (c) is a schematic diagram of the result of XOR logic operation; Figure 6 A schematic diagram of the operation results of the logical operation system simulating the neuron dynamics of the biological brain provided in the embodiment of the present application, which implements the or-not logical operation based on the neuron dynamics; wherein, Figure 6 (a) is a schematic diagram of the input and output intensity in the XP&YP polarization direction. Figure 6 (b) is a schematic diagram of the result of the OR-NOT logic operation; Explanation of the reference numerals in the specification: 1. injection light module; 11. first tunable laser; 12. second tunable laser; 2. optical modulation module; 21. first arbitrary waveform generator; 22. first Mach-Zehnder modulator; 23. second arbitrary waveform generator; 24. second Mach-Zehnder modulator; 25. first optical coupler; 3. vertical cavity surface emitting laser; 31. laser driver; 4. output module; 41. photodetector; 42. oscilloscope; 43. spectrum analyzer; 44. second optical coupler. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Example 1

[0022] See also Figure 1 , Figure 1 The schematic diagram of the structure of the logic operation system for simulating the dynamics of biological brain neurons provided in this application includes: an injection light module 1, a light modulation module 2, a vertical cavity surface emitting laser 3 and an output module 4.

[0023] The injection optical module 1 is used to generate a first injection optical signal and a second injection optical signal with tunable wavelengths, wherein the frequencies of the first injection optical signal and the second injection optical signal are both greater than or equal to the response frequency of the vertical cavity surface emitting laser 3 .

[0024] The input end of the optical modulation module 2 is connected to the output end of the injection optical module 1, and is used to modulate and couple the first injection optical signal and the second injection optical signal, and output a coupled signal.

[0025] The input end of the vertical cavity surface emitting laser 3 is connected to the output end of the optical modulation module 2 for receiving the coupling signal and performing laser response to the two injected optical signals in the coupling signal in the XP polarization direction and the YP polarization direction respectively, thereby realizing logic operation.

[0026] The input end of the output module 4 is connected to the output end of the vertical cavity surface emitting laser 3, and is used to output the laser response of the vertical cavity surface emitting laser 3 in a time sequence form to obtain a logic operation result.

[0027] Specifically, two-thirds of human cortical neurons are able to perform XOR and NOR operations. These neurons determine whether to trigger spikes through the bioelectric signals received by their dendritic structures from two different paths, thereby performing logical operations. Biology shows that although dendritic electrodes successfully trigger somatic spikes at currents close to the threshold level, the effect of inducing somatic spikes under simultaneous stimulation of multiple currents is poor, or fails completely. Therefore, only a single biological neuron can achieve XOR and NOR logical operations. Based on the above inspiration, the present application considers using two orthogonal polarization modes of a laser as the first input and second input of a logical operation, and redefines the input of a Boolean value, so that a dual-input single-output logical operation system can be constructed using a single laser.

[0028] Furthermore, the vertical cavity surface emitting laser 3 is a special semiconductor laser. Different from the traditional edge emitting laser, the laser cavity of the vertical cavity surface emitting laser 3 is perpendicular to the substrate, so the light beam is emitted from the top or bottom of the device. Thanks to the unique structural design, the threshold current of the vertical cavity surface emitting laser 3 is low, usually only a few milliamperes, which makes it have great advantages in low-power applications. At the same time, based on the dual polarization characteristics of the vertical cavity surface emitting laser 3, the present application uses the two orthogonal polarization modes of the vertical cavity surface emitting laser 3 as the first input end and the second input end of the logic operation. The present application finds that by adjusting the frequency of the two injected light signals in the coupling signal input to the vertical cavity surface emitting laser, the excitability threshold of the vertical cavity surface emitting laser can be changed, so that the vertical cavity surface emitting laser makes an excitation response to the two injected light signals in the coupling signal in the form of spikes in the XP polarization and YP polarization directions respectively, and its output excitation response is manifested as the result of the logic operation on the two signals in the coupling signal.

[0029] Therefore, the present application utilizes the two-path injection light signals generated by the injection light module 1 to simulate the signal transmission between biological neurons, utilizes the optical modulation module 2 to modulate and couple the injection light signals, generates a coupling signal that can change the excitability threshold of the vertical cavity surface emitting laser 3, utilizes the vertical cavity surface emitting laser 3 to simulate the biological neurons to respond to the coupling signal, thereby constructing a logic operation system that simulates the dynamics of biological brain neurons, and only needs one laser to construct a dual-input single-output logic operation system, which has a simple structure, low cost, and reduces the system size and power consumption; at the same time, it avoids the influence of the response time difference of different semiconductor lasers on the accuracy of the operation results, and there is no need to match the timing of the two signals by extending the operation time, so that the logic operation rate of the entire system is increased to GHz, which greatly improves the logic operation efficiency, so that it can be used in various application scenarios with high requirements for real-time data processing.

[0030] Furthermore, the logic operation system constructed based on two semiconductor lasers in the prior art can only realize XOR logic operation, and cannot realize NOR logic operation. This is because NOR logic operation needs to output high-level signals when both inputs are low-level signals. For the traditional logic operation system constructed using two semiconductor lasers, it is necessary to make the entire system output high-level signals when there is no input light signal in both semiconductor lasers. However, when there is no input light signal, the semiconductor laser will not produce a spike-shaped excitation response, and the system cannot output a high-level signal. Therefore, limited by the input and output characteristics of the semiconductor laser, the existing logic operation system constructed using semiconductor lasers cannot realize NOR logic operation. The logic operation system for simulating the dynamics of biological brain neurons provided by the present application can realize both XOR logic operation and NOR logic operation.

[0031] Specifically, in some embodiments, the optical modulation module 2 is also used to modulate and couple the first injected light signal and the second injected light signal when performing an exclusive-OR logic operation, adjust the frequency of the first injected light signal to a first preset range, and adjust the frequency of the second injected light signal to a second preset range, so that in the modulated first injected light signal and the second injected light signal, one injected light signal is a high-level signal and the other injected light signal is a low-level signal, and output a coupled signal so that the vertical cavity surface emitting laser 3 receives the coupled signal, and under the excitation of the two injected light signals in the coupled signal before modulation, no peaks are generated in the XP polarization direction and the YP polarization direction, and under the excitation of the two injected light signals in the coupled signal after modulation, a peak is generated in the XP polarization direction or the YP polarization direction, thereby realizing an exclusive-OR logic operation.

[0032] Furthermore, when the response frequency of the vertical cavity surface emitting laser 3 is 20 ns -1When the first preset range is 0ns -1 ~5ns -1 , and the second preset range is 19ns -1 ~22ns -1 ; or, the first preset range is 19ns -1 ~21ns -1 , and the second preset range is 0ns -1 ~5.5ns -1 .

[0033] Specifically, in some embodiments, the optical modulation module 2 is also used to modulate and couple the first injected light signal and the second injected light signal when performing an OR-NOT logical operation, adjust the frequency of the first injected light signal to a third preset range, and adjust the frequency of the second injected light signal to a fourth preset range, so that the modulated first injected light signal and the second injected light signal are both low-level signals, and output a coupled signal so that the vertical cavity surface emitting laser 3 receives the coupled signal, and under the excitation of the two injected light signals in the coupled signal before modulation, no peaks are generated in the XP polarization direction and the YP polarization direction, and under the excitation of the two injected light signals in the coupled signal after modulation, peaks are generated in the XP polarization direction and the YP polarization direction, thereby realizing an OR-NOT logical operation.

[0034] Furthermore, when the response frequency of the vertical cavity surface emitting laser 3 is 20 ns -1 The third preset range is 10ns -1 ~18ns -1 , the fourth preset range is 6ns -1 ~10ns -1 .

[0035] Furthermore, if Figure 1 As shown, the injection optical module 1 includes a first tunable laser 11 and a second tunable laser 12 .

[0036] The first tunable laser 11 is used to generate a first injection optical signal with tunable wavelength.

[0037] The second tunable laser 12 is used to generate a second injection optical signal with tunable wavelength.

[0038] Furthermore, the optical modulation module 2 includes a first arbitrary waveform generator 21 , a first Mach-Zehnder modulator 22 , a second arbitrary waveform generator 23 , a second Mach-Zehnder modulator 24 and a first optical coupler 25 .

[0039] The first arbitrary waveform generator 21 is used to generate a first modulated electrical signal.

[0040] An input end of the first Mach-Zehnder modulator 22 is connected to an output end of the first tunable laser 11 and an output end of the first arbitrary waveform generator 21 , and is used to modulate the first injected optical signal based on the first modulating electrical signal.

[0041] The second arbitrary waveform generator 23 is used to generate a second modulated electrical signal.

[0042] An input end of the second Mach-Zehnder modulator 24 is connected to an output end of the second tunable laser 12 and an output end of the second arbitrary waveform generator 23 , and is used to modulate the second injected optical signal based on the second modulated electrical signal.

[0043] The first optical coupler 25 is used to couple the first injection optical signal and the second injection optical signal, and output a coupled signal.

[0044] In a specific example of the present application, the first modulated electrical signal and the second modulated electrical signal generated by the first arbitrary waveform generator 21 and the second arbitrary waveform generator 23 both include a rectangular square wave electrical signal with adjustable duty cycle and variable modulation depth and an electrical signal that changes continuously with distance information.

[0045] Specifically, Figure 1 As shown, the vertical cavity surface emitting laser 3 is connected to a laser driver 31 , and the laser driver 31 is used to adjust the operating temperature and driving current of the vertical cavity surface emitting laser 3 .

[0046] Furthermore, the output module 4 includes a photodetector 41 and an oscilloscope 42 .

[0047] The input end of the photodetector 41 is connected to the output end of the VCSEL 3 , and is used to convert the laser response of the VCSEL 3 into an electrical signal.

[0048] The input end of the oscilloscope 42 is connected to the output end of the photodetector 41 for outputting the electrical signal in a time sequence form.

[0049] Optionally, in some embodiments, the output module 4 further includes a spectrum analyzer 43 .

[0050] An input end of the spectrum analyzer 43 is connected to an output end of the VCSEL 3 , and is used to obtain spectrum response data corresponding to the laser response of the VCSEL 3 .

[0051] Optionally, the photodetector 41 and the spectrum analyzer 43 can be directly connected to the output end of the VCSEL 3, or the output of the VCSEL 3 can be first divided into two paths using an optical coupling device and then input into the photodetector 41 and the spectrum analyzer 43 respectively.

[0052] Specifically, in some embodiments of the present application, the output module 4 further includes a second optical coupler 44 .

[0053] The input end of the second optical coupler 44 is connected to the output end of the vertical cavity surface emitting laser 3, the first output end thereof is connected to the input end of the photodetector 41, and the second output end thereof is connected to the input end of the spectrum analyzer 43, and is used for dividing the laser response of the vertical cavity surface emitting laser 3 into a first laser response and a second laser response, and inputting the first laser response into the photodetector 41 so that the photodetector 41 converts the first laser response into an electrical signal, and inputting the second laser response into the spectrum analyzer 43 so that the spectrum analyzer 43 obtains the spectrum response data corresponding to the second laser response. Example 2

[0054] Based on the logic operation system for simulating biological brain neuron dynamics provided in the above-mentioned embodiment 1, the embodiment of the present application also provides an XOR logic operation method for simulating biological brain neuron dynamics, such as Figure 2 As shown, the XOR logic operation method for simulating biological brain neuron dynamics includes: S10: using an injection optical module to generate a first injection optical signal and a second injection optical signal with tunable wavelengths; wherein the frequencies of the first injection optical signal and the second injection optical signal are both greater than or equal to the response frequency of the vertical cavity surface emitting laser; S20: using an optical modulation module to modulate and couple the first injected optical signal and the second injected optical signal respectively, adjusting the frequency of the first injected optical signal to a first preset range, and adjusting the frequency of the second injected optical signal to a second preset range, so that one of the modulated first injected optical signal and the second injected optical signal is a high-level signal, and the other injected optical signal is a low-level signal, and outputting a coupled signal; S30: using a vertical cavity surface emitting laser to receive a coupling signal, and under the excitation of two injection optical signals in the coupling signal before modulation, no peaks are generated in the XP polarization direction and the YP polarization direction, and under the excitation of two injection optical signals in the coupling signal after modulation, a peak is generated in the XP polarization direction or the YP polarization direction, thereby realizing an exclusive OR logic operation; S40: using the output module to output the laser response of the vertical cavity surface emitting laser in a time sequence form to obtain an XOR logic operation result.

[0055] Furthermore, when the response frequency of the vertical cavity surface emitting laser is 20ns -1 When the first preset range is 0ns -1 ~5ns -1 , and the second preset range is 19ns -1 ~22ns -1 ; or, the first preset range is 19ns-1 ~21ns -1 , and the second preset range is 0ns -1 ~5.5ns -1 . Example 3

[0056] Based on the logic operation system for simulating biological brain neuron dynamics provided in the above-mentioned embodiment 1, the embodiment of the present application also provides a method for simulating biological brain neuron dynamics or non-logic operation, such as Figure 3 As shown, the OR-NOT logic operation method for simulating biological brain neuron dynamics includes: S100: generating a first injection optical signal and a second injection optical signal with tunable wavelengths using an injection optical module; wherein the frequencies of the first injection optical signal and the second injection optical signal are both greater than or equal to the response frequency of the vertical cavity surface emitting laser; S200: Use the optical modulation module to modulate and couple the first injection optical signal and the second injection optical signal respectively, adjust the frequency of the first injection optical signal to a third preset range, and adjust the frequency of the second injection optical signal to a fourth preset range, so that the modulated first injection optical signal and the second injection optical signal are both low-level signals, and output a coupling signal; S300: using a vertical cavity surface emitting laser to receive a coupling signal, and under the excitation of two injection optical signals in the coupling signal before modulation, no peaks are generated in the XP polarization direction and the YP polarization direction, and under the excitation of two injection optical signals in the coupling signal after modulation, peaks are generated in the XP polarization direction and the YP polarization direction, thereby realizing a non-OR logic operation; S400: using an output module to output the laser response of the vertical cavity surface emitting laser in a time sequence form to obtain a logical NOR operation result.

[0057] Furthermore, when the response frequency of the vertical cavity surface emitting laser is 20ns -1 The third preset range is 10ns -1 ~18ns -1 , the fourth preset range is 6ns -1 ~10ns -1 .

[0058] Specifically, the polarization characteristics of the vertical cavity surface emitting laser are explained below. The spin reversal model is a theoretical model that describes the dynamics of spin-polarized electrons in semiconductor lasers. In semiconductors, electron spins can be reversed through various mechanisms, including spin-orbit coupling and spin-spin interaction. Spin reversal not only affects the recombination process of carriers, but also directly acts on the polarization state of photons emitted by the laser. Therefore, the study of the interaction between photons and electron spins using the spin reversal model can be used to explain and predict: the polarization behavior of the vertical cavity surface emitting laser during spin polarization injection or spin-orbit coupling effects. Among them, the spin reversal model used to describe the dynamic characteristics of the vertical cavity surface emitting laser can be described using the following equation: , , , , in, and denote the slowly varying amplitudes of XP and YP polarization modes, respectively; express The complex conjugate of express The complex conjugate of Represents the total number of carrier inversions between the conduction band and the valence band; It represents the difference between the number of carrier inversions in the spin-up and spin-down radiation channels; represents the light field attenuation rate; represents the line width enhancement factor; and represent the linear anisotropy of dichroism and birefringence, respectively; express The decay rate of represents the normalized pump current; represents the spin-reversal relaxation rate; Indicates the intensity of light injected in XP polarization mode; It represents the angular frequency detuning between the XP polarization mode injected light and the center frequency of the vertical cavity surface emitting laser; , represents the frequency difference between the XP polarization mode of the first tunable laser and the vertical cavity surface emitting laser; Indicates the light intensity injected in YP polarization mode; It represents the angular frequency detuning between the YP polarization mode injected light and the center frequency of the vertical cavity surface emitting laser; , Indicates the frequency difference between the second tunable laser and the YP polarization mode of the vertical cavity surface emitting laser. In a specific example of the present application, the values ​​of the various parameters in the provided logic operation system are as follows: , .

[0059] See also Figure 4 , Figure 4 The figure shows a schematic diagram of biological neuron dynamics characteristics about dual-path light injection intensity simulated by a logic operation system simulating biological brain neuron dynamics provided by an embodiment of the present application, wherein: Figure 4 (a) is a schematic diagram of the activation peak response of the XP polarization and YP polarization modes to the coupled signal. In the figure, the XP area indicates that a peak response is generated only in the XP polarization direction, the YP area indicates that a peak response is generated only in the YP polarization direction, and the XP&YP area indicates that a peak response is generated in both the XP polarization and YP polarization directions. Figure 4 (b) is the timing diagram of the output of the logic operation system when a peak response is generated only in the XP polarization direction. Figure 4 (c) is the timing diagram of the output of the logic operation system when a peak response is generated only in the YP polarization direction. Figure 4 (d) is a timing diagram of the output of the logic operation system when a peak response is generated in both the XP polarization and the YP polarization directions.

[0060] from Figure 4 It can be seen that when the frequency of the first injected optical signal changes from 20ns -1 Adjust to 2ns -1 , and the frequency of the second injected optical signal is from 21ns -1 Adjusted to 21ns -1 When the first input end is reduced to a low level and the second input end is kept at a high level, the output of the vertical cavity surface emitting laser is high level, realizing XOR; when the frequency of the first injected optical signal changes from 20ns -1 Adjust to 20ns -1 , and the frequency of the second injected optical signal is from 21ns -1 Adjusted to 5ns -1 When the first input terminal is kept at a high level and the second input terminal is reduced to a low level, the output of the vertical cavity surface emitting laser is high level, realizing XOR; when the frequency of the first injected optical signal changes from 20ns to -1 Adjusted to 17.5ns -1 , and the frequency of the second injected optical signal is from 21ns -1 Adjusted to 6.5ns -1When , the vertical cavity surface emitting laser releases a peak in both the XP polarization and YP polarization directions, that is, when the first input terminal and the second input terminal are both reduced to a low level, the output of the vertical cavity surface emitting laser is a high level, realizing NOR.

[0061] like Figure 5 The figure shows a schematic diagram of the operation result of implementing an XOR logic operation based on neuron dynamics in a logic operation system simulating biological brain neuron dynamics provided by an embodiment of the present application; wherein, Figure 5 (a) is a schematic diagram of the input and output intensity in the XP polarization direction. Figure 5 (b) is a schematic diagram of the input and output intensity in the YP polarization direction. Figure 5 (c) is a schematic diagram of the XOR logic operation result; Figure 5 It can be seen that in the process of logical operation, when the operation result should be a high level "1", it will be displayed in the form of a spike in the corresponding timing, and when the operation result should be a low level "0", no spike response will be generated in the corresponding timing. For example, when the input value is 20ns -1 When the input value is about 2ns, it means the input Boolean value is high level "1"; when the input value is about 2ns -1 , indicating that the input Boolean value is a low level "0"; it can be clearly seen in the table that only when the input is different, a spike is generated, representing the output "1", successfully realizing the exclusive OR logic operation (XOR); in addition, continuous XOR is realized at the front and back ends of the interception time period, and discrete XOR is realized in the middle area. And it can be seen from the figure that the interval between the two spikes is close to 1ns, which means that the speed of the XOR operation of the logic operation system simulating the dynamics of biological brain neurons provided by the present application is very close to GHz.

[0062] Figure 6 A schematic diagram of the operation results of the logical operation system simulating the neuron dynamics of the biological brain provided in the embodiment of the present application, which implements the or-not logical operation based on the neuron dynamics; wherein, Figure 6 (a) is a schematic diagram of the input and output intensity in the XP&YP polarization direction. Figure 6 (b) is a schematic diagram of the result of the OR-NOT logic operation; Figure 6 It can be seen that only when the two signals are simultaneously stimulated by the weaker stimulus signal "0", a spike pulse "1" will be stimulated in the corresponding timing, and no spike pulse will be stimulated in other cases. For example, when the input value is 20ns -1 When the input value XP is about 14ns, it means the input Boolean logic value is high level "1"; when the input value XP is about 14ns -1 When or input value YP is about 17ns -1 When Figure 4The XP&YP area in the graph indicates that the input Boolean logic value is a low level "0"; it can be clearly seen in the table that only when the inputs are all "0" will a spike be generated, representing the output "1", successfully realizing the NOR logic operation; in addition, at the front end of the interception time period, a continuous NOR is realized, and at the back end, a discrete NOR is realized. Similarly, when performing the NOR operation, the interval between the two spikes is less than 1ns, only 0.7ns, which means that the speed of the NOR operation of the logic operation system simulating the dynamics of biological brain neurons provided by the present application will exceed 1GHz.

[0063] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0064] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0065] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0066] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1The steps for the functions specified in one or more boxes.

[0067] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A logical operation system simulating the dynamics of biological brain neurons, characterized in that: include: An injection optical module, used to generate a first injection optical signal and a second injection optical signal with tunable wavelengths; wherein the frequencies of the first injection optical signal and the second injection optical signal are both greater than or equal to the response frequency of the vertical cavity surface emitting laser; an optical modulation module, whose input end is connected to the output end of the injection optical module, and is used to modulate and couple the first injection optical signal and the second injection optical signal, and output a coupled signal; A vertical cavity surface emitting laser, whose input end is connected to the output end of the optical modulation module, is used to receive the coupling signal and perform laser response to two injection optical signals in the coupling signal in the XP polarization direction and the YP polarization direction respectively, so as to realize logic operation; The output module has an input end connected to the output end of the vertical cavity surface emitting laser and is used to output the laser response of the vertical cavity surface emitting laser in a time sequence form to obtain a logic operation result.

2. The logic operation system for simulating biological brain neuron dynamics according to claim 1 is characterized in that: The injection optical module comprises: A first tunable laser, used to generate a first injection optical signal with tunable wavelength; The second tunable laser is used to generate a second injection optical signal with tunable wavelength.

3. The logic operation system for simulating biological brain neuron dynamics according to claim 2 is characterized in that: The optical modulation module comprises: A first arbitrary waveform generator, used to generate a first modulated electrical signal; a first Mach-Zehnder modulator, whose input end is connected to the output end of the first tunable laser and the output end of the first arbitrary waveform generator, and is used to modulate the first injected optical signal based on the first modulating electrical signal; A second arbitrary waveform generator, used to generate a second modulated electrical signal; a second Mach-Zehnder modulator, whose input end is connected to the output end of the second tunable laser and the output end of the second arbitrary waveform generator, and is used to modulate the second injected optical signal based on the second modulating electrical signal; The first optical coupler is used to couple the first injection optical signal and the second injection optical signal, and output a coupled signal.

4. The logic operation system for simulating biological brain neuron dynamics according to claim 1 is characterized in that: The output module comprises: A photodetector, whose input end is connected to the output end of the vertical cavity surface emitting laser, and is used to convert the laser response of the vertical cavity surface emitting laser into an electrical signal; An oscilloscope, whose input end is connected to the output end of the photodetector, is used to output the electrical signal in a time sequence form.

5. The logic operation system for simulating biological brain neuron dynamics according to claim 4 is characterized in that: The output module also includes: An optical spectrum analyzer, whose input end is connected to the output end of the vertical cavity surface emitting laser, is used to obtain optical spectrum response data corresponding to the laser response of the vertical cavity surface emitting laser.

6. The logic operation system for simulating biological brain neuron dynamics according to claim 5, characterized in that: The output module also includes: A second optical coupler, whose input end is connected to the output end of the vertical cavity surface emitting laser, whose first output end is connected to the input end of the photodetector, and whose second output end is connected to the input end of the spectrum analyzer, is used to divide the laser response of the vertical cavity surface emitting laser into a first laser response and a second laser response, and input the first laser response to the photodetector so that the photodetector converts the first laser response into an electrical signal, and input the second laser response to the spectrum analyzer so that the spectrum analyzer obtains spectrum response data corresponding to the second laser response.

7. A XOR operation method for simulating the dynamics of biological brain neurons, characterized in that: The method is implemented by using the logic operation system for simulating biological brain neuron dynamics according to any one of claims 1 to 6, comprising: Using an injection optical module to generate a first injection optical signal and a second injection optical signal with tunable wavelengths; wherein the frequencies of the first injection optical signal and the second injection optical signal are both greater than or equal to the response frequency of the vertical cavity surface emitting laser; Using an optical modulation module to modulate and couple the first injected optical signal and the second injected optical signal respectively, adjusting the frequency of the first injected optical signal to a first preset range, and adjusting the frequency of the second injected optical signal to a second preset range, so that in the modulated first injected optical signal and the second injected optical signal, one injected optical signal is a high-level signal, and the other injected optical signal is a low-level signal, and outputting a coupled signal; The coupling signal is received by a vertical cavity surface emitting laser, and under the excitation of the two injection optical signals in the coupling signal before modulation, no peaks are generated in the XP polarization direction and the YP polarization direction, and under the excitation of the two injection optical signals in the coupling signal after modulation, a peak is generated in the XP polarization direction or the YP polarization direction, thereby realizing an exclusive OR logic operation; The output module is used to output the laser response of the vertical cavity surface emitting laser in a time sequence form to obtain an exclusive OR logic operation result.

8. The XOR operation method for simulating biological brain neuron dynamics according to claim 7, characterized in that: When the response frequency of the vertical cavity surface emitting laser is 20ns -1 hour, The first preset range is 0ns -1 ~5ns -1 , and the second preset range is 19ns -1 ~22ns -1 ; or, The first preset range is 19ns -1 ~21ns -1 , and the second preset range is 0ns -1 ~5.5ns -1 .

9. A method for simulating the dynamics of biological brain neurons, characterized in that: The method is implemented by using the logic operation system for simulating biological brain neuron dynamics according to any one of claims 1 to 6, comprising: Using an injection optical module to generate a first injection optical signal and a second injection optical signal with tunable wavelengths; wherein the frequencies of the first injection optical signal and the second injection optical signal are both greater than or equal to the response frequency of the vertical cavity surface emitting laser; Using an optical modulation module to modulate and couple the first injection optical signal and the second injection optical signal respectively, adjusting the frequency of the first injection optical signal to a third preset range, and adjusting the frequency of the second injection optical signal to a fourth preset range, so that the modulated first injection optical signal and the second injection optical signal are both low-level signals, and outputting a coupling signal; The coupling signal is received by a vertical cavity surface emitting laser, and under the excitation of the two injection optical signals in the coupling signal before modulation, no peaks are generated in the XP polarization direction and the YP polarization direction, and under the excitation of the two injection optical signals in the coupling signal after modulation, peaks are generated in the XP polarization direction and the YP polarization direction, thereby realizing a non-OR logic operation; The output module is used to output the laser response of the vertical cavity surface emitting laser in a time sequence form to obtain a logical NOR operation result.

10. The method for simulating biological brain neuron dynamics according to claim 9, characterized in that: When the response frequency of the vertical cavity surface emitting laser is 20ns -1 When the third preset range is 10ns -1 ~18ns -1 , the fourth preset range is 6ns -1 ~10ns -1 .

Images