A bionic ladder neuron based on electro-optical hybrid device and its manufacturing method

Abstract

The present invention relates to a bionic cascade neuron based on an electro-optical hybrid device and a method for making the same, wherein the bionic cascade neuron based on an electro-optical hybrid device comprises an optical fiber jumper and an electro-optical modulator arranged on the end face of the optical fiber jumper; the electro-optical modulator comprises a modulation layer, the photoelectric characteristics of which change with external stimuli, the modulation layer receives a light beam signal from the optical fiber jumper, generates a changing signal response according to the changing photoelectric characteristics, and realizes the simulated behavior of the bionic neuron. The bionic cascade neuron based on an electro-optical hybrid device described in the present invention can extract the spatiotemporal information of a dynamic image, and process dynamic visual information at a high information transmission rate.

Description

Technical Field

[0001] The invention relates to the field of optical fiber devices and bionic neuromorphic computing, and in particular to a bionic ladder neuron based on an electro-optical hybrid device. Background Art

[0002] The IoT artificial intelligence technology has developed rapidly in the past decade. It embeds artificial intelligence technology into IoT devices and systems to improve data analysis, intelligent decision-making and autonomous learning capabilities. Among them, dynamic visual information processing technology, as an important part of IoT artificial intelligence technology, is the key to enabling image data collection, analysis, processing and decision-making capabilities in practical applications such as autonomous driving, security monitoring, and smart homes. In the current big data era, dynamic visual information processing technology requires higher information transmission and processing rates to capture and analyze dynamic image data in real time and efficiently, which puts higher requirements on the signal delay, computing efficiency and communication rate of the device system.

[0003] The development of bionic optoelectronic neuromorphic computing devices provides an implementation plan for dynamic visual information processing technology. This field imitates biological neurons and synaptic mechanisms in electrical or optical behaviors by designing the materials, structures, and regulation methods of electronic devices to achieve computing tasks. In particular, researchers have recently developed bionic cascade neurons based on the cascade neuron behavior of insects in electronic devices, which can achieve in-situ perception and efficient processing of dynamic visual image information by integrating spatiotemporal information in a targeted manner. However, to solve this problem, additional optoelectronic conversion modules and communication equipment need to be added, which leads to a decrease in the system's computing and energy utilization efficiency.

[0004] In recent years, computing platforms based on fiber optic devices have made great progress. By building electro-optic modulators on the basis of optical fibers and using electrical drive signals to control the transmission of optical information, an all-fiber communication and computing platform can be realized. However, existing fiber optic electro-optic modulators still have gaps in bionic neuron behavior and neuromorphic computing capabilities, which need to be developed urgently. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a bionic cascade neuron based on an electro-optical hybrid device, implement the bionic fiber optic cascade neuron behavior on the transmission or reflection spectrum of the optical fiber, and realize the dynamic visual information processing function.

[0006] A bionic ladder neuron based on an electro-optic hybrid device comprises an optical fiber jumper and an electro-optic modulator arranged on the end face of the optical fiber jumper; the electro-optic modulator comprises a modulation layer, whose photoelectric characteristics change with external stimulation, the modulation layer receives a light beam signal from the optical fiber jumper, generates a changing signal response according to the changing photoelectric characteristics, and realizes the simulated behavior of the bionic neuron.

[0007] Furthermore, the electro-optic modulator includes a stacked bottom electrode, a modulation layer and a top electrode, wherein the bottom electrode and the top electrode are electrically connected to an external voltage signal source to provide a variable voltage stimulus to the modulation layer to control changes in the photoelectric characteristics of the modulation layer.

[0008] Furthermore, the electro-optic modulator includes a stacked bottom electrode, a modulation layer, a top electrode, and a voltage signal source with adjustable voltage; the voltage signal source provides variable voltage stimulation to the modulation layer through the bottom electrode and the top electrode to control the change of the photoelectric characteristics of the modulation layer.

[0009] Furthermore, the bottom electrode completely covers the end face of the core diameter of the optical fiber jumper; the modulation layer is distributed in the area of ​​the bottom electrode, is concentric with the bottom electrode, and is larger than 3 / 5 of the area of ​​the bottom electrode; the top electrode is distributed in the area of ​​the modulation layer, is concentric with the modulation layer, and is larger than 2 / 5 of the area of ​​the modulation layer.

[0010] Furthermore, the bottom electrode and the top electrode are made of transparent conductive material.

[0011] Furthermore, the modulation layer is a two-dimensional material.

[0012] Furthermore, the optical fiber jumper is a single-mode optical fiber or a multi-mode optical fiber.

[0013] The present invention also provides a method for manufacturing a bionic ladder neuron based on an electro-optical hybrid device, comprising the steps of:

[0014] depositing a bottom electrode on the end face of the optical fiber patch cord;

[0015] Compounding a two-dimensional material on the bottom electrode to form a modulation layer;

[0016] A top electrode is deposited on the modulation layer.

[0017] Furthermore, the method further comprises the steps of:

[0018] depositing a bottom electrode on the end face of the optical fiber patch cord;

[0019] Compounding a two-dimensional material on the bottom electrode to form a modulation layer;

[0020] depositing a top electrode on the modulation layer;

[0021] The bottom electrode is connected to the voltage signal source and the top electrode is connected to the voltage signal source through wires.

[0022] Furthermore, before the two-dimensional material is composited on the bottom electrode to form a modulation layer, the method also includes the following steps: preparing the two-dimensional material.

[0023] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A structural diagram of a bionic ladder neuron based on an electro-optical hybrid device provided by the present invention.

[0025] Figure 2 for Figure 1 An end cross-sectional view of the bionic ladder neuron based on the electro-optical hybrid device.

[0026] Figure 3 This is a structural diagram of the detection system based on bionic ladder neuron behavior.

[0027] Figure 4 for Figure 1 Schematic diagram of the reflection / transmission spectrum of the detection system.

[0028] Figure 5 for Figure 3 The modulation characteristic diagram of voltage on reflection / transmission spectrum in the detection system. DETAILED DESCRIPTION

[0029] The applicant carefully analyzed the existing bionic cascade neurons and found that it is difficult for traditional optoelectronic devices to avoid the real-time transmission and communication problems of optical information in dynamic visual information processing. To solve this problem, it is necessary to add additional optoelectronic conversion modules and communication equipment, which will lead to a decrease in the system's computing and energy utilization efficiency. Therefore, the applicant tried to use optical fiber devices instead of traditional optical devices in bionic cascade neurons, by building an electro-optical modulator on the basic optical fiber jumper, using an electric drive signal to regulate the optical information transmission behavior, and detecting its reflection / transmission spectrum with bionic cascade neuron behavior in the bionic cascade neuron system.

[0030] Based on the above invention concept, the applicant provides a bionic ladder neuron based on an electro-optical hybrid device, see Figure 1 The bionic ladder neuron based on the electro-optic hybrid device includes an optical fiber jumper 1 and an electro-optic modulator 2. The electro-optic modulator 2 is arranged on the end face of the optical fiber jumper 1, covers the light emitting surface of the optical fiber jumper 1, and receives light beam stimulation from the optical fiber jumper 1.

[0031] Example 1

[0032] See also Figure 2The end face of the optical fiber jumper 1 is polished and smooth. It can be a single-mode optical fiber, which configures the input light into a single-mode optical component and precisely controls the single-mode optical component; it can also be a multi-mode optical fiber, which configures the input light into multiple-mode optical components, including multiple optical frequencies and multiple polarization orientations and other waveguide modes. Compared with the existing solutions that can only be applied to single-mode optical fibers or multi-mode optical fibers, the bionic ladder neuron based on the electro-optical hybrid device of the present invention has a wider range of applications, and the corresponding optical fiber can be selected according to the actual light source conditions and needs.

[0033] In one embodiment, the optical fiber jumper 1 includes an optical fiber cladding 3 and an optical fiber core 4, wherein the optical fiber core 4 is covered in the optical fiber cladding 3; the electro-optic modulator 2 includes a stacked bottom electrode 5, a modulation layer 6, a top electrode 7, and an electrically connected voltage signal source 8, wherein the bottom electrode 5 is connected to one pole of the external voltage signal source 8 through a transmission line, and the top electrode 7 is connected to the other pole of the external voltage signal source 8 through a transmission line. The voltage signal source 8 provides voltage stimulation to the modulation layer 6 through the bottom electrode 5 and the top electrode 7, and the photoelectric characteristics of the modulation layer 6 can be controlled by changing the voltage intensity of the voltage signal source 8.

[0034] The bottom electrode 5 completely covers the end face of the optical fiber core 4, ensuring that the bottom electrode 5 can be stably fixed on the light-emitting surface of the optical fiber core 4, and the light beam from the optical fiber core 4 can completely pass through the bottom electrode 5, and its material selection can be metals such as Pt, Al, and Ag.

[0035] The modulation layer 6 is a two-dimensional material, and has a patterned surface to give it a specific shape, which can be mass-produced and repeatedly prepared according to actual needs. The two-dimensional material can be graphene, Te, MXenes, black scale, molybdenum disulfide, etc.; the modulation layer 6 is distributed in the area of ​​the bottom electrode 5 and is concentric with the bottom electrode 5, ensuring that the modulation layer 6 can receive the light beam stimulation from the optical fiber core 4, and the area of ​​the modulation layer 6 is greater than 3 / 5 of the area of ​​the bottom electrode 5, ensuring that the light beam stimulation received by the modulation layer 6 has sufficient intensity;

[0036] The top electrode 7 is distributed in the area of ​​the modulation layer 6 and is concentric with the modulation layer 6. It is isolated from direct contact with the bottom electrode 5 by the modulation layer 6, ensuring that no short circuit or leakage occurs between the top electrode 7 and the bottom electrode 5. The top electrode 7 is larger than 2 / 5 of the area of ​​the modulation layer 6, ensuring that a sufficiently large area of ​​electric field is formed between the top electrode 7 and the bottom electrode 5, so that the modulation layer 6 can receive sufficient voltage stimulation. The material selected can be metals such as Pt, Al, and Ag.

[0037] Then, the bionic ladder neuron based on the electro-optical hybrid device of the present invention is prepared by the following method:

[0038] Clean the end face of the optical fiber jumper;

[0039] depositing a bottom electrode on the end face of the optical fiber patch cord;

[0040] Compounding a two-dimensional material on the bottom electrode to form a modulation layer;

[0041] performing patterning on the modulation layer;

[0042] depositing a top electrode on the modulation layer;

[0043] The bottom electrode is connected to a voltage signal source and the top electrode is connected to the voltage signal source through wires.

[0044] In particular, cleaning the end face of the optical fiber jumper specifically includes: fixing the end face of the optical fiber jumper with a clamp, connecting the optical fiber end face cleaning machine, injecting the cleaning agent and compressed air into the connector for cleaning, injecting nitrogen gas to blow dry after cleaning, and removing the optical fiber jumper from the connector to prepare for the end face recombination of the optoelectronic modulator.

[0045] The deposition of the bottom electrode on the end face of the optical fiber jumper specifically includes: fixing the optical fiber jumper with a clamp, placing it in a magnetron sputtering chamber perpendicular to the target surface, and using a DC sputtering power supply to deposit an Au electrode on the end face; during the sputtering process, the working pressure is 1-10 Pa, the argon gas flow rate is 10-20 sccm, the sputtering power is 60-80 W, and the sputtering time is 3-5 min, and the deposition of the bottom electrode of the electro-optic modulator is completed on the end face of the optical fiber jumper.

[0046] Preferably, a two-dimensional material can be directly deposited on the bottom electrode to form a modulation layer. The cleaned optical fiber jumper is removed from the cladding and placed in a planar connection table, which is then placed in a chemical vapor deposition equipment chamber, with CH4 as the carbon source, H2 and A2 mixed gas as the carrier, and a working pressure of 1-10 Pa, to perform direct deposition of the two-dimensional material on the bottom electrode at low temperature (400-600°C).

[0047] Preferably, the two-dimensional material can be prepared first, and then the two-dimensional material can be transferred to the bottom electrode to form a modulation layer. First, polymethyl methacrylate (PMMA) as a polymer transfer medium is spin-coated onto the Cu foil deposited with the two-dimensional material at a speed of 500 rpm / s for a duration of 30 s, and then the PMMA film with the two-dimensional material attached is obtained based on the peeling method by utilizing the adhesion of PMMA; after being separated from the original substrate, it is adhered to the end face of the optical fiber jumper, and finally, PMMA is cleaned off with acetone to obtain an optical fiber jumper composited with the two-dimensional material.

[0048] Specifically, the two-dimensional material can also be transferred to the bottom electrode by the following method: placing the prepared two-dimensional material / Cu foil substrate in a FeCl3 corrosion solution, etching the copper foil substrate to obtain a two-dimensional material suspended on the surface of the solution, and then using an immersion method to directly transfer the two-dimensional material to the bottom electrode deposited on the end face of the optical fiber.

[0049] Before transferring the two-dimensional material to the bottom electrode, the two-dimensional material can be prepared by the following method: the two-dimensional material graphene is prepared on the copper foil by chemical vapor deposition, wherein CH4 is used as the carbon source, and a mixture of H2 and Ar2 is used as the carrier gas, and the working pressure is 10 -1 -10 3 Pa, and graphene deposition was carried out at 800-1000°C.

[0050] The patterning process of the modulation layer specifically includes: fixing the optical fiber jumper with a clamp and connecting it to a rotating table; dropping 50 μL of photoresist on the end face of the optical fiber fixed on the rotating table, and spin coating at a speed of 5000-8000 rpm / s for 30-50 s, followed by soft baking on a hot plate at 150-200°C for 2-5 min; placing the rotating table on the sample stage of electron beam lithography, and using the electron beam to expose the photoresist to a specified pattern, and then removing the optical fiber from the rotating table and immersing it in a developer and a stop solution for 1 min respectively; then, fixing the optical fiber jumper with a clamp and placing it in dry etching to obtain a patterned modulation layer.

[0051] Depositing the top electrode on the modulation layer specifically includes: after obtaining the patterned modulation layer, reconnecting the optical fiber to the rotating table, spin-coating the photoresist, and then using electron beam lithography to expose the photoresist in a patterned manner. At this time, the pattern area needs to be within the area where the modulation layer is located to isolate the top electrode from the bottom electrode; after development, the optical fiber jumper is fixed in the magnetron sputtering chamber using a clamp, and a direct current power supply is used to sputter the Au electrode on the modulation layer. During the sputtering process, the working pressure is 1-10 Pa, the argon gas flow rate is 10-20 sccm, the sputtering power is 60-80 W, and the sputtering time is 3-5 min; finally, the optical fiber with the Au top electrode deposited is immersed in an acetone solution for 2 min to completely remove the photoresist, and the lift-off process is used to realize the patterning of the top electrode to complete the production of the bionic ladder neuron.

[0052] Example 2

[0053] The electro-optic modulator 2 described in this embodiment only includes a stacked bottom electrode 5, a modulation layer 6 and a top electrode 7, but does not include a voltage signal source 8. The bottom electrode 5 and the top electrode 7 are electrically connected to an external voltage signal source 8, respectively. The remaining structure is the same as that in Example 1 and will not be repeated here.

[0054] Then, the bionic ladder neuron based on the electro-optical hybrid device of the present invention is prepared by the following method:

[0055] Clean the end face of the optical fiber jumper;

[0056] depositing a bottom electrode on the end face of the optical fiber patch cord;

[0057] Compounding a two-dimensional material on the bottom electrode to form a modulation layer;

[0058] performing patterning on the modulation layer;

[0059] A top electrode is deposited on the modulation layer.

[0060] In this embodiment, the method for making the bionic ladder neuron based on the electro-optical hybrid device of the present invention is the same as that in Example 1, except that there is no need to connect the bottom electrode with a voltage signal source and the top electrode with the voltage signal source through wires, and will not be repeated here.

[0061] Those skilled in the art will appreciate that the photoelectric properties of two-dimensional materials can also be achieved by regulating temperature and pressure parameters to replace the voltage stimulation of the voltage signal source. At this time, the bottom electrode 5 and the top electrode 7 only serve to support the modulation layer 6, and there is no need to limit the conductivity of the material.

[0062] After obtaining the above-mentioned bionic algebraic neuron based on the electro-optical hybrid device, the present invention detects the behavior of the simulated bionic algebraic neuron through the following detection system.

[0063] The detection system includes an incident light coupler 9, a reflected light coupler 12, a transmitted light coupler 14, a spectroscope 10, a light source 11, a reflective spectrometer 13 and a transmittance spectrometer 15. The incident light coupler 9 is arranged between the bionic ladder neuron and the spectroscope 10, and the light beam emitted by the light source 11 is reflected on the spectroscope 11 and enters the bionic ladder neuron; the reflected light coupler 12 is arranged between the reflective spectrometer 13 and the spectroscope 10, and the reflective spectrometer 13 receives the light beam reflected by the bionic ladder neuron; the transmitted light coupler 14 is arranged between the transmittance spectrometer 15 and the spectroscope 10, and the transmittance spectrometer 15 receives the light beam transmitted by the bionic ladder neuron.

[0064] The light source 11 emits an initial light beam, which is reflected by the spectroscope 10 and coupled into the optical fiber jumper 1 of the bionic ladder neuron by the incident light coupler 9 to form an initial information light beam; the initial information light beam is irradiated on the electro-optic modulator 2 to form a reflected modulated light beam, and is transmitted through the electro-optic modulator 2 to form a transmitted modulated light beam; the reflected modulated light beam propagates along the optical fiber jumper 1 in the opposite direction to the initial information light beam, and is transmitted through the spectroscope 10 after passing through the incident light coupler 9 again to form a reflected information light beam; the reflected information light beam passes through the reflected light coupler 12 and enters the reflected spectrometer 13, and the reflected spectrometer 13 receives and analyzes the reflected spectrum characteristics of the bionic ladder neuron contained in the reflected information beam; the transmitted modulated light beam propagates in the same direction as the initial information beam, and enters the transmitted spectrometer 15 after passing through the transmitted light coupler 14, and the transmitted spectrometer 15 receives and analyzes the transmitted spectrum characteristics of the bionic ladder neuron contained in the transmitted information beam. It will be understood by those skilled in the art that the reflected light coupler 12 and the transmitted light coupler 14 are not necessary, and their purpose is to reduce stray light entering the reflected light spectrometer 13 and the transmitted light spectrometer 15, and to ensure that the factors affecting the light beams entering the two are the same, so that the parameters that need to be considered when analyzing the reflected / transmitted spectra are the same.

[0065] The following is a detailed description of the overall implementation process of the detection system.

[0066] The operation process of the detection system for detecting the reflective spectrum characteristics includes: inputting incident light-voltage regulating the two-dimensional material-reflective characteristic modulation-outputting the reflective spectrum;

[0067] First, the detection system performs a pre-coding process of time-domain optical information, that is, the image grayscale value (0-255) of the dynamic visual information is encoded into the frequency characteristics of the optical pulse; then, the pulse light carrying the specific information is generated by the light source 11, and is input into the incident light coupler 9 after passing through the spectroscope 10, so as to transmit the encoded optical information to the bionic optical fiber ladder neurons; after the encoded optical information is input, the voltage signal source 8 applies voltage stimulation to the bottom electrode 5 and the top electrode 7 of the electro-optical modulator 2; after the optical information passes through the electro-optical modulator 2, the spectroscope 10 and the reflective light coupler 12 transmit the regulated reflected light to the reflective spectrometer 13 to detect the behavior of the bionic ladder neurons. Preferably, the image grayscale value (0-255) of the dynamic optical information can also be encoded into the phase, pulse width, amplitude and interval time characteristics of the optical pulse. In the case where the optical fiber jumper 1 is a multimode optical fiber, the encoded dynamic optical information can be transmitted simultaneously through the optical frequency and polarization waveguide mode in the multimode optical fiber.

[0068] The operation process of the detection system for detecting the transmission spectrum characteristics is different from that for detecting the reflection spectrum characteristics only in the devices involved. The principles are exactly the same and will not be described in detail here.

[0069] See also Figure 4 The reflection / transmission characteristics of bionic algebraic neurons can be changed through encoded light information pulses, causing them to exhibit bionic algebraic neuron behaviors.

[0070] See also Figure 5 By controlling the different voltage amplitude signals of the voltage signal source 8 in the electro-optic modulator 2 to regulate the photoelectric properties of the two-dimensional material, a modulation ratio of the voltage signal to the light reflection spectrum is achieved that is ≥10, and a modulation ratio of the voltage signal to the light information transmission spectrum is achieved that is ≥1.

[0071] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A bionic ladder neuron based on an electro-optical hybrid device, characterized in that: It includes an optical fiber jumper and an electro-optical modulator arranged on the end surface of the optical fiber jumper; The electro-optic modulator includes a modulation layer, whose photoelectric characteristics change with external stimulation. A voltage signal source provides a variable voltage stimulus to the modulation layer to control the change of the photoelectric characteristics of the modulation layer. The modulation layer receives the light beam signal from the optical fiber jumper and generates a changing signal response according to the changing photoelectric characteristics, thereby realizing the simulated behavior of the bionic neuron. The image grayscale value of dynamic visual information is encoded into the frequency characteristics of light pulses, and the reflection / transmission characteristics of bionic algebraic neurons are changed so that the bionic algebraic neurons exhibit algebraic neuron behavior.

2. The bionic cascade neuron based on the electro-optical hybrid device according to claim 1, characterized in that: The electro-optic modulator includes a stacked bottom electrode, a modulation layer and a top electrode. The bottom electrode and the top electrode are electrically connected to an external voltage signal source to provide a variable voltage stimulus to the modulation layer to control the change of the photoelectric characteristics of the modulation layer.

3. The bionic cascade neuron based on the electro-optical hybrid device according to claim 1, characterized in that: The electro-optic modulator includes a stacked bottom electrode, a modulation layer, a top electrode, and a voltage signal source with adjustable voltage; the voltage signal source provides a variable voltage stimulus to the modulation layer through the bottom electrode and the top electrode to control the change of the photoelectric characteristics of the modulation layer.

4. The bionic cascade neuron based on the electro-optical hybrid device according to claim 2 or 3, characterized in that: The bottom electrode completely covers the end face of the core diameter of the optical fiber jumper; the modulation layer is distributed in the area of ​​the bottom electrode, is concentric with the bottom electrode, and is larger than 3 / 5 of the area of ​​the bottom electrode; the top electrode is distributed in the area of ​​the modulation layer, is concentric with the modulation layer, and is larger than 2 / 5 of the area of ​​the modulation layer.

5. The bionic cascade neuron based on the electro-optical hybrid device according to claim 4, characterized in that: The bottom electrode and the top electrode are made of transparent conductive material.

6. The bionic cascade neuron based on the electro-optical hybrid device according to claim 5, characterized in that: The modulation layer is a two-dimensional material.

7. The bionic cascade neuron based on the electro-optical hybrid device according to claim 6, characterized in that: The optical fiber jumper is a single-mode optical fiber or a multi-mode optical fiber.

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