Neuron and nerve synapse integrated unit based on photonic crystal and preparation method thereof

Abstract

The invention provides a neuron and neuronal synapse integrated unit based on a photonic crystal, which can be applied to the technical field of semiconductor lasers, and comprises a semiconductor optical amplifier, a first electrical isolation region and a photonic crystal semiconductor laser which are etched on a semiconductor epitaxial structure, the semiconductor optical amplifier and the photonic crystal semiconductor laser can independently inject current; the photonic crystal semiconductor laser includes: a gain region including a first group of photonic crystals; the saturable absorber region comprises a second group of photonic crystals; and the second electrical isolation region is positioned between the gain region and the saturable absorber region and is used for electrically isolating the gain region from the saturable absorber region, so that current can be injected into the gain region and the saturable absorber region independently. The weight of the signal is adjusted through the neural synapse of the semiconductor optical amplifier, the single-mode pulse optical signal is provided through the photonic crystal semiconductor laser, and a specific wavelength is selected for oscillation and output by adjusting photonic crystal parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor lasers, and more particularly to a neuron and synapse integration unit based on a photonic crystal and a preparation method thereof. Background Art

[0002] Machine learning and deep learning based on artificial neural networks have made landmark progress in recent years, especially in low-power artificial intelligence with many applications. However, electro-neuromorphic computing is limited by the electronic bottleneck, suffering from problems such as small bandwidth, high power consumption, large latency, large signal distortion and crosstalk, and quantum effect interference with multicast. Optical neuromorphic computing has advantages in these aspects. Optical computing is superior to electrical computing both in terms of energy consumption and computing power density. At present, the functions of deep learning or machine learning have been realized using optoelectronic devices or all-optical devices. However, optical computing chips have problems such as high cost, difficulty in integration and expansion of the integration scale. For high-density large-scale optical computing integrated chips, on-chip integrated semiconductor lasers as laser neurons will provide efficient laser neuron signals. At the same time, semiconductor laser neurons are integrated with semiconductor optical amplifier synapse devices to expand the integration scale and improve the integration density. This task requires a mirror between the semiconductor laser neurons and the semiconductor optical amplifier synapses. Since it is impossible to realize a mirror by coating between the on-chip integrated functional devices. One possible solution is to deeply etch a one-dimensional distributed Bragg (1D-DBR) mirror. The second method is to construct a mirror by introducing a photonic crystal structure, and this method has been used to realize the reflection and selection of optical modes in various material systems such as silicon-based, GaAs-based, and InP-based. Compared with the 1D-DBR mirror, the photonic crystal provides greater flexibility for the high-density large-scale integration of microcavity lasers, short-cavity lasers and more complex photonic crystal optical devices (such as filters, ultra-small scale bent waveguides, synthesizers), thereby expanding the integration scale of the optical neural network chip. Therefore, the research on photonic crystal semiconductor laser neurons and synapse units has broad application prospects. Summary of the Invention

[0003] (I) Technical Problems to be Solved

[0004] In view of the above problems, the present invention provides a neuron and synapse integration unit based on a photonic crystal and a preparation method thereof. The weight of the signal is adjusted by the synapse, and a single-mode pulsed optical signal is provided by the photonic crystal semiconductor laser. By adjusting the photonic crystal parameters, a specific wavelength is selected for oscillation and output. This solution provides greater flexibility for horizontally and vertically expanding the integration scale and realizing a large-density large-scale integrated optical neural network computing chip, and is used to solve problems such as the difficulty in expanding the integration scale of current semiconductor laser neuron chips.

[0005] (II) Technical Solutions

[0006] In view of the above technical problems, an embodiment of the present invention provides a neuron and synapse integration unit based on a photonic crystal and a preparation method thereof.

[0007] According to a first aspect of the present invention, there is provided a neuron and synapse integration unit based on a photonic crystal, characterized by comprising: a semiconductor optical amplifier etched on a semiconductor epitaxial structure, a first electrical isolation region, and a photonic crystal semiconductor laser, wherein the first electrical isolation region is used to electrically isolate the semiconductor optical amplifier from the photonic crystal semiconductor laser, so that the semiconductor optical amplifier and the photonic crystal semiconductor laser can inject current independently; the photonic crystal semiconductor laser includes: a gain region disposed at one end of the photonic crystal semiconductor laser close to the first electrical isolation region, the gain region including a first group of photonic crystals located at one end of the surface of the gain region close to the first electrical isolation region; a saturable absorber region located at the end of the photonic crystal semiconductor laser far from the first electrical isolation region, the saturable absorber region including a second group of photonic crystals located at one end of the surface of the saturable absorber region far from the first electrical isolation region; a second electrical isolation region located between the gain region and the saturable absorber region, for electrically isolating the gain region from the saturable absorber region, so that the gain region and the saturable absorber region can inject current independently.

[0008] In some exemplary embodiments, the structure of the semiconductor optical amplifier includes a bent waveguide structure, and the performance of the semiconductor optical amplifier is adjusted by setting the bending curvature radius and length of the bent waveguide structure.

[0009] In some exemplary embodiments, the semiconductor optical amplifier serves as a synapse and is used to adjust the weight of an optical signal according to the intensity of an applied electrical signal; the photonic crystal semiconductor laser can generate a single-mode pulsed laser and serves as a photonic crystal semiconductor laser neuron to simulate the characteristics of a biological neuron.

[0010] In some exemplary embodiments, the lengths of the gain region, the saturable absorber region, and the second electrical isolation region can be designed according to requirements; and by adjusting the length of the gain region, the gain region can provide sufficient gain.

[0011] In some exemplary embodiments, the first group of photonic crystals and the second group of photonic crystals form a laser oscillation cavity as a reflector to select a specific wavelength, which is fed back and output in the laser oscillation cavity.

[0012] In some exemplary embodiments, the first group of photonic crystals and the second group of photonic crystals include one of one-dimensional photonic crystals, two-dimensional photonic crystals, or three-dimensional photonic crystals; defects are introduced into the first group of photonic crystals and the second group of photonic crystals to select specific wavelengths; and by adjusting the shapes and sizes of the first group of photonic crystals and the second group of photonic crystals, light of specific wavelengths is selected and reflected, and their reflectivities and transmittances are adjusted, wherein the geometric parameters and refractive indices of the first group of photonic crystals and the second group of photonic crystals are the same or different.

[0013] In some exemplary embodiments, the first electrical isolation region achieves electrical isolation by one of etching a slot or ion implantation; the second electrical isolation region achieves electrical isolation by etching a slot.

[0014] In some exemplary embodiments, the semiconductor epitaxial structure includes: an N-type epitaxial layer; an active region located on the surface of the N-type epitaxial layer, which provides gain for a photonic crystal semiconductor laser and a semiconductor optical amplifier respectively through electrical injection; a P-type epitaxial layer located on the surface of the active region away from the N-type epitaxial layer, and the P-type epitaxial layer is a ridge waveguide structure.

[0015] In some exemplary embodiments, the material of the semiconductor epitaxial structure includes III-V compound semiconductor materials.

[0016] According to the second aspect of the present invention, a preparation method of a neuron and synapse integration unit based on photonic crystals is provided, including: obtaining a semiconductor epitaxial structure and forming an etching mask on the semiconductor epitaxial structure; through multiple photolithography and etching processes, a first electrical isolation region, a gain region, a saturable absorber region, and a second electrical isolation region are formed on the semiconductor epitaxial structure, wherein one side of the first electrical isolation region is a semiconductor optical amplifier, and the other side is a photonic crystal semiconductor laser, and the photonic crystal semiconductor laser includes a gain region, a saturable absorber region, and a second electrical isolation region; using electron beam lithography technology and etching technology, a first group of photonic crystals and a second group of photonic crystals are respectively formed on the surfaces of the gain region and the saturable absorber region; growing an insulating medium, performing photolithography and etching, and respectively forming current injection windows on the semiconductor optical amplifier, the gain region, and the saturable absorber region; growing P-side metal, performing photolithography and etching on the P-side metal, forming a patterned electrode and achieving electrical isolation; thinning and polishing the back surface of the epitaxial wafer, and growing N-side metal; and dicing and cleaving to obtain a neuron and synapse integration unit based on photonic crystals.

[0017] (III) Beneficial effects

[0018] As can be seen from the above technical solutions, a neuron and synapse integration unit based on photonic crystals and a preparation method thereof provided by the embodiments of the present invention have at least the following beneficial effects:

[0019] (1)Adjust the weight of the signal through the synapse, and provide a single-mode pulsed optical signal through the photonic crystal semiconductor laser, where a specific wavelength is selected for oscillation and output by adjusting the photonic crystal parameters. This solution provides greater flexibility for horizontally and vertically expanding the integration scale and realizing a large-density and large-scale integrated optical neural network computing chip.

[0020] (2)The overall laser is active, which is beneficial to make up for the power loss caused by electrical isolation and etching of the photonic crystal, improve the power of the entire laser. The semiconductor epitaxial material has the advantages of a wide gain range and a low threshold current. The electrical injection pumping method is convenient to use and easy to achieve high-precision control. Description of the Drawings

[0021] Through the following description of the embodiments of the present invention with reference to the drawings, the above content and other objects, features and advantages of the present invention will become clearer. In the drawings:

[0022] Figure 1 Schematically shows a structural diagram of a neuron and synapse integration unit based on a photonic crystal according to an embodiment of the present invention;

[0023] Figure 2 Schematically shows a top view of a neuron and synapse integration unit based on a photonic crystal according to an embodiment of the present invention; and

[0024] Figure 3 Schematically shows a flowchart of a preparation method of a neuron and synapse integration unit based on a photonic crystal according to an embodiment of the present invention.

[0025] Reference Signs:

[0026] 1 - Semiconductor optical amplifier; 2 - Photonic crystal semiconductor laser; 3 - Gain region; 4 - Saturable absorber region; 5 - First group of photonic crystals; 6 - Second group of photonic crystals; 7 - Second electrical isolation region; 8 - First electrical isolation region; 9 - P-type epitaxial layer; 10 - Active region; 11 - N-type epitaxial layer. Detailed Embodiments

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0028] Figure 1Schematically shows a structural diagram of a neuron and synapse integration unit based on a photonic crystal according to an embodiment of the present invention; Figure 2 Schematically shows a top view of a neuron and synapse integration unit based on a photonic crystal according to an embodiment of the present invention.

[0029] As Figure 1 and Figure 2 shown, a neuron and synapse integration unit based on a photonic crystal according to an embodiment of the present invention includes: a semiconductor optical amplifier 1 etched on a semiconductor epitaxial structure, a first electrical isolation region 8, and a photonic crystal semiconductor laser 2. Among them, the first electrical isolation region 8 is used to electrically isolate the semiconductor optical amplifier 1 from the photonic crystal semiconductor laser 2, so that the semiconductor optical amplifier 1 and the photonic crystal semiconductor laser 2 can independently inject current; the photonic crystal semiconductor laser 2 includes: a gain region 3, disposed at one end of the photonic crystal semiconductor laser 2 close to the first electrical isolation region 8. The gain region 3 includes a first group of photonic crystals 5, and the first group of photonic crystals 5 is located at one end of the surface of the gain region 3 close to the first electrical isolation region 8; a saturable absorber region 4, located at the end of the photonic crystal semiconductor laser 2 far from the first electrical isolation region 8. The saturable absorber region 4 includes a second group of photonic crystals 6, and the second group of photonic crystals 6 is located at the end of the surface of the saturable absorber region 4 far from the first electrical isolation region 8; a second electrical isolation region 7, located between the gain region 3 and the saturable absorber region 4, for electrically isolating the gain region 3 from the saturable absorber region 4, so that the gain region 3 and the saturable absorber region 4 can independently inject current.

[0030] In an embodiment of the present invention, the semiconductor optical amplifier 1 serves as a synapse and is used to adjust the weight of an optical signal according to the intensity of an applied electrical signal; the photonic crystal semiconductor laser 2 can generate single-mode pulsed laser and serves as a neuron of the photonic crystal semiconductor laser 2 to simulate the characteristics of a biological neuron.

[0031] In some exemplary embodiments, the structure of the semiconductor optical amplifier 1 includes a bent waveguide structure, and the performance of the semiconductor optical amplifier 1 is adjusted by setting the bending curvature radius and length of the bent waveguide structure.

[0032] In some exemplary embodiments, the lengths of the gain region 3, the saturable absorber region 4, and the second electrical isolation region 7 can be designed according to requirements; and by adjusting the length of the gain region 3, the gain region 3 can provide sufficient gain.

[0033] In some exemplary embodiments, the first group of photonic crystals 5 and the second group of photonic crystals 6 form a laser oscillation cavity as a mirror for selecting a specific wavelength, which is fed back and output in the laser oscillation cavity.

[0034] In some exemplary embodiments, the geometric parameters and refractive indices of the first group of photonic crystals 5 and the second group of photonic crystals 6 can be designed to be the same or different according to requirements. For example, the first group of photonic crystals 5 can be low-reflectivity photonic crystals, and the second group of photonic crystals 6 can be high-reflectivity photonic crystals. The photonic bandgap can be adjusted by changing the shape, lattice arrangement, etc. of the photonic crystals. By introducing defects into the photonic crystals, a specific wavelength can be selected. And by adjusting the shapes and sizes of the first group of photonic crystals 5 and the second group of photonic crystals 6, light of a specific wavelength can be selected and feedback, and its reflectivity and transmittance can be adjusted. The first group of photonic crystals 5 and the second group of photonic crystals 6 include one of one-dimensional photonic crystals, two-dimensional photonic crystals, or three-dimensional photonic crystals.

[0035] In the embodiments of the present invention, the type of the second group of photonic crystals 6, the depth, size, and number of the photonic crystals need to be designed according to the actual situation to select and feedback light of a specific wavelength and adjust its reflectivity and transmittance. By introducing defects into the first group of photonic crystals 5 and the second group of photonic crystals 6, a specific wavelength can be selected.

[0036] In some exemplary embodiments, the gain region 3 and the saturable absorber region 4 of the photonic crystal semiconductor laser 2 are electrically isolated by the second electrical isolation region 7, and light is connected and transmitted through a waveguide. The ways for the first electrical isolation region 8 to achieve electrical isolation include one of etching a slot or ion implantation; the way for the second electrical isolation region 7 to achieve electrical isolation includes etching a slot. The gain region 3 of the photonic crystal semiconductor laser 2 is connected to the semiconductor optical amplifier 1 and directly transmitted to the output of the semiconductor optical amplifier 1.

[0037] In some exemplary embodiments, the semiconductor epitaxial structure includes: an N-type epitaxial layer 11; an active region 10, located on the surface of the N-type epitaxial layer 11, providing gain for the photonic crystal semiconductor laser 2 and the semiconductor optical amplifier 1 respectively through electrical injection; a P-type epitaxial layer 9, located on the surface of the active region 10 away from the N-type epitaxial layer 11 and the P-type epitaxial layer 9 is a ridge waveguide structure. Optionally, the material of the semiconductor epitaxial structure includes III-V compound semiconductor materials.

[0038] In an embodiment of the present invention, the photonic crystal semiconductor laser 2 and the semiconductor optical amplifier 1 are both designed and fabricated on the same semiconductor epitaxial structure, and the entire region has the same active region 10; preferably, the semiconductor material is an InP-based AlGaInAs multi-quantum well compound semiconductor epitaxial material, and the material of the active region 10 includes a multi-quantum well of AlGaInAs. The electrical injection pumping method is adopted, and electrical injection is used to provide gain for the photonic crystal semiconductor laser 2 and the semiconductor optical amplifier 1 respectively. The active region 10 of the semiconductor epitaxial structure is used to generate optical gain, which is convenient and practical, and is easy to achieve high-precision control. The overall active design is beneficial to make up for the power loss caused by the electrical isolation region between the semiconductor optical amplifier 1 and the gain region 3 of the photonic crystal semiconductor laser 2 and the etched photonic crystal, and improve the output optical power of the entire optical pulse neuron (or laser). The semiconductor material has the advantages of a wide gain range and a low threshold current. The electrical injection pumping method is convenient to use and integrate, and is easy to achieve high-precision control.

[0039] In an embodiment of the present invention, when testing the neuron and synapse integration unit based on a photonic crystal, it is necessary to apply electricity to the gain region 3, the saturable absorber region 4, and the semiconductor optical amplifier 1 at the same time. Among them, a forward current is applied to the semiconductor optical amplifier 1 and the gain region 3, and a reverse bias voltage is applied to the saturable absorber region 4, and finally the leaky integrate-and-fire (LIF) model of the neuron is realized.

[0040] Figure 3 The flowchart of a preparation method of a neuron and synapse integration unit based on a photonic crystal according to an embodiment of the present invention is schematically shown.

[0041] As Figure 3 shown, a preparation method of a neuron and synapse integration unit based on a photonic crystal according to an embodiment of the present invention includes steps S110-S170.

[0042] In step S110, a semiconductor epitaxial structure is obtained, and an etching mask is formed on the semiconductor epitaxial structure.

[0043] In an embodiment of the present invention, the method for forming an etching mask includes growing a layer of dielectric or spin-coating a photoresist or other insulating materials on the semiconductor epitaxial material.

[0044] In step S120, through multiple photolithography and etching processes, a first electrical isolation region 8, a gain region 3, a saturable absorber region 4, and a second electrical isolation region 7 are formed on the semiconductor epitaxial structure. Among them, one side of the first electrical isolation region 8 is the semiconductor optical amplifier 1, and the other side is the photonic crystal semiconductor laser 2. The photonic crystal semiconductor laser 2 includes a gain region 3, a saturable absorber region 4, and a second electrical isolation region 7.

[0045] In step S130, using electron beam lithography technology and etching technology, a first group of photonic crystals 5 and a second group of photonic crystals 6 are respectively formed on the surface of the gain region 3 and the surface of the saturable absorber region 4.

[0046] In step S140, an insulating medium is grown, lithographed, and etched to form current injection windows in the semiconductor optical amplifier 1, the gain region 3, and the saturable absorber region 4 respectively.

[0047] In step S150, P-side metal is grown, lithographed, and etched to form a patterned electrode and achieve electrical isolation.

[0048] In step S160, the back surface of the epitaxial wafer is thinned and polished, and N-side metal is grown.

[0049] In step S170, dicing and cleavage are performed to obtain a neuron and synapse integration unit based on photonic crystals.

[0050] Embodiment 1

[0051] In Embodiment 1, an InP-based AlGaInAs multiple quantum well semiconductor epitaxial structure in the C band is selected.

[0052] The total length of the synapses of the semiconductor optical amplifier 1 is 250 µm, the radian conforms to a 7° Bessel curve, the total length of the neurons of the photonic crystal semiconductor laser 2 is 1000 μm, the length of the gain region 3 is 940 µm, the length of the electrical isolation region is 10 μm, and the length of the saturable absorber region 4 is 50 μm. In this embodiment, the electrical isolation method used is an etched slot.

[0053] Taking the preparation method of optical pulse neurons with AlGaInAs multiple quantum well materials in the C band and selecting single transverse electric mode based on two-dimensional photonic crystal structure as an example for illustration. The preparation method of the neuron and synapse integration unit based on photonic crystals includes:

[0054] S1. Grow a layer of dielectric or spin-coat a photoresist or other insulating material on the semiconductor epitaxial material to form an etching mask.

[0055] S2. Through processes such as multiple lithography and etching, form a gain region 3, a saturable absorber region 4, and an electrical isolation region on the semiconductor epitaxial material.

[0056] S3. Use electron beam lithography technology and etching technology to form two groups of photonic crystals.

[0057] S4. Grow another layer of insulating medium again, lithograph and etch to form a current injection window.

[0058] S5. Grow P-side metal, lithograph and etch the metal to form a patterned electrode and achieve electrical isolation.

[0059] S6. Thinning and polishing the back surface of the epitaxial wafer, and growing N-side metal.

[0060] S7. After dicing and cleavage, a photonic crystal semiconductor laser 2 neuron and neuron-neurosynapse chip are obtained.

[0061] Those skilled in the art can understand that the features described in the various embodiments of the present invention can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments of the present invention can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present invention.

Claims

1. A neuron and synapse integrated unit based on a photonic crystal, characterized in that, Comprising: A semiconductor optical amplifier, a first electrical isolation region, and a photonic crystal semiconductor laser etched on a semiconductor epitaxial structure, wherein the first electrical isolation region is used to electrically isolate the semiconductor optical amplifier from the photonic crystal semiconductor laser, so that the semiconductor optical amplifier and the photonic crystal semiconductor laser can be independently injected with current; The photonic crystal semiconductor laser includes: A gain region disposed at one end of the photonic crystal semiconductor laser close to the first electrical isolation region, the gain region including a first group of photonic crystals, and the first group of photonic crystals being located at one end of the surface of the gain region close to the first electrical isolation region; A saturable absorber region located at one end of the photonic crystal semiconductor laser far from the first electrical isolation region, the saturable absorber region including a second group of photonic crystals, and the second group of photonic crystals being located at one end of the surface of the saturable absorber region far from the first electrical isolation region; A second electrical isolation region located between the gain region and the saturable absorber region, for electrically isolating the gain region from the saturable absorber region, so that the gain region and the saturable absorber region can be independently injected with current.

2. The integrated unit of neurons and synapses based on photonic crystals according to claim 1, wherein The structure of the semiconductor optical amplifier includes a bent waveguide structure, and the performance of the semiconductor optical amplifier is adjusted by setting the bending curvature radius and length of the bent waveguide structure.

3. The integrated unit of neurons and synapses based on photonic crystals according to claim 1, characterized in that, The semiconductor optical amplifier serves as a neural synapse and is used to adjust the weight of an optical signal according to the intensity of an applied electrical signal; The photonic crystal semiconductor laser can generate single-mode pulsed laser, serving as a photonic crystal semiconductor laser neuron to simulate the characteristics of biological neurons.

4. The integrated unit of neurons and synapses based on photonic crystals according to claim 1, characterized in that, The lengths of the gain region, the saturable absorber region, and the second electrical isolation region can be designed according to requirements; and By adjusting the length of the gain region, the gain region can provide sufficient gain.

5. The integrated unit of neurons and synapses based on photonic crystals according to claim 1, characterized in that, The first group of photonic crystals and the second group of photonic crystals form a laser oscillation cavity as a mirror, for selecting a specific wavelength, feeding back and outputting in the laser oscillation cavity.

6. The integrated unit of neurons and neural synapses based on photonic crystals according to claim 1, characterized in that The first group of photonic crystals and the second group of photonic crystals include one of one-dimensional photonic crystals, two-dimensional photonic crystals, or three-dimensional photonic crystals; By introducing defects in the first group of photonic crystals and the second group of photonic crystals to select a specific wavelength; and By adjusting the shapes and sizes of the first group of photonic crystals and the second group of photonic crystals to select and feedback light of a specific wavelength and adjust its reflectivity and transmittance, wherein the geometric parameters and refractive indices of the first group of photonic crystals and the second group of photonic crystals are the same or different.

7. The integrated unit of neurons and synapses based on photonic crystals according to claim 1, wherein The way for the first electrical isolation region to achieve electrical isolation includes one of etching a slot or ion implantation; The way for the second electrical isolation region to achieve electrical isolation includes etching a slot.

8. The integrated unit of neurons and synapses based on photonic crystals according to claim 1, characterized in that The semiconductor epitaxial structure includes: An N-type epitaxial layer; An active region located on the surface of the N-type epitaxial layer, providing gain for the photonic crystal semiconductor laser and the semiconductor optical amplifier respectively through electrical injection; The P-type epitaxial layer is located on the surface of the active region away from the N-type epitaxial layer, and the P-type epitaxial layer is a ridge waveguide structure.

9. The integrated unit of neurons and synapses based on photonic crystals according to claim 1, wherein The material of the semiconductor epitaxial structure includes III-V compound semiconductor materials.

10. A preparation method of a photonic crystal-based neuron and synapse integration unit according to any one of claims 1-9, characterized in that, The method includes: Obtaining a semiconductor epitaxial structure and forming an etching mask on the semiconductor epitaxial structure; Forming a first electrical isolation region, a gain region, a saturable absorber region, and a second electrical isolation region on the semiconductor epitaxial structure through multiple photolithography and etching processes, wherein one side of the first electrical isolation region is a semiconductor optical amplifier, and the other side is a photonic crystal semiconductor laser, and the photonic crystal semiconductor laser includes a gain region, a saturable absorber region, and a second electrical isolation region; Using electron beam lithography technology and etching technology to form a first group of photonic crystals and a second group of photonic crystals on the surfaces of the gain region and the saturable absorber region respectively; Growing an insulating medium, performing photolithography and etching to form current injection windows in the semiconductor optical amplifier, the gain region, and the saturable absorber region respectively; Growing P-side metal, performing photolithography and etching on the P-side metal to form a patterned electrode and achieve electrical isolation; Thinning and polishing the back surface of the epitaxial wafer, and growing N-side metal; and Dicing and cleaving to obtain the integrated unit of neurons and synapses based on photonic crystals.

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