Antimonide single-mode photonic crystal microcavity laser and preparation method thereof

Abstract

The invention discloses an antimonide single-mode photonic crystal microcavity laser and a preparation method thereof, and relates to the technical field of semiconductor lasers, the laser comprises an N-type electrode, an N-type substrate, an N-type buffer layer, an N-type light limiting layer, a quantum well active layer, a P-type light limiting layer, a P-type cover layer, a dielectric layer and a P-type electrode which are sequentially arranged from bottom to top, two bosses are arranged on the upper portion of the P-type electrode, a ridge waveguide is arranged between the two bosses, a groove is formed between the bosses and the ridge waveguide, the depth of the groove is downwards in contact with the interior of the P-type cover layer but not in contact with the P-type light limiting layer, a photonic crystal is arranged on the ridge waveguide, and the photonic crystal is of a periodic air hole arrangement structure in the ridge waveguide direction. According to the invention, the photonic crystal is coupled to the ridge waveguide of the narrow ridge semiconductor laser through an etching method, so that the spectral characteristic and wavelength stability of an antimonide semiconductor are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor lasers, and particularly to an antimonide single-mode photonic crystal microcavity laser and a preparation method thereof. Background Art

[0002] Antimonide lasers operate in the mid-infrared band of 2-4 μm and have important application values in the fields of national defense security, environmental monitoring, industrial production, communication interconnection, etc. However, in applications such as gas sensing and optical communication, it is required that the laser has narrow linewidth and stable wavelength output, which means that the laser must operate in the single transverse and single longitudinal mode. Due to the multi-wavelength lasing characteristics of the traditional Fabry-Perot resonator, it cannot directly meet this requirement, and usually an additional filtering structure is needed to achieve single-mode lasing. For lasers based on materials such as gallium arsenide (GaAs) and indium phosphide (InP), single-mode lasing can be achieved by introducing a buried Bragg grating (such as DFB or DBR structure) through secondary epitaxy. However, the layer structure of antimonide lasers usually contains a high aluminum component, which is prone to oxidation during the secondary epitaxy process, resulting in serious losses and performance degradation. Therefore, there is an urgent need for an antimonide single-mode photonic crystal microcavity laser and a preparation method thereof to solve the above problems. Summary of the Invention

[0003] The purpose of the present invention is to provide an antimonide single-mode photonic crystal microcavity laser and a preparation method thereof that can improve the longitudinal mode narrow linewidth characteristics and stability of semiconductor lasers and reduce the losses caused by secondary epitaxy during the preparation process of semiconductor lasers.

[0004] To achieve the above purpose, in the first aspect of the present invention, an antimonide single-mode photonic crystal microcavity laser is provided, which includes an N-type electrode, an N-type substrate, an N-type buffer layer, an N-type optical confinement layer, a quantum well active layer, a P-type optical confinement layer, a P-type capping layer, a dielectric layer, and a P-type electrode arranged in sequence from bottom to top. Two bosses are provided on the upper part of the P-type electrode, and a ridge waveguide is arranged between the two bosses. A groove is arranged between the boss and the ridge waveguide, and the depth of the groove extends downward into the interior of the P-type capping layer but does not reach the P-type optical confinement layer. A photonic crystal is arranged on the ridge waveguide, and the photonic crystal is a periodic air hole arrangement structure along the direction of the ridge waveguide.

[0005] Preferably, the distance between two adjacent air holes at the center of the photonic crystal is a first distance, and the distance between any other two non-center adjacent air holes of the photonic crystal is a second distance, and the first distance is greater than the second distance.

[0006] Preferably, the difference between the first distance and the second distance is within one period length of an original photonic crystal, where the original photonic crystal is a photonic crystal with the second distance between any two adjacent air holes.

[0007] Preferably, the air holes are circular air holes.

[0008] Preferably, the refractive index of the air holes is 1, and the refractive index of the ridge waveguide is greater than that of the photonic crystal.

[0009] Preferably, the photonic crystal and the groove are formed by etching, and the etching depth of the photonic crystal is equal to that of the groove.

[0010] Preferably, the material of the N-type electrode is at least one of AuGe, Ni, Au, Ti, and Pt.

[0011] Preferably, the material of the P-type electrode is at least one of Pd, Pt, Au, and Zn.

[0012] Preferably, the material of the N-type substrate is GaSb;

[0013] The material of the N-type buffer layer is GaSb, and the thickness of the N-type buffer layer is 356 - 376 nm;

[0014] The material of the N-type optical confinement layer is AlGaAsSb, and the thickness of the N-type optical confinement layer is 1 - 3 μm;

[0015] The material of the quantum well active layer is at least one of AlGaAsSb and InGaAsSb, and the thickness of the quantum well active layer is 550 - 570 nm;

[0016] The material of the P-type optical confinement layer is AlGaAsSb, and the thickness of the P-type optical confinement layer is 1 - 3 μm;

[0017] The material of the P-type cap layer is GaSb, and the thickness of the P-type cap layer is 240 - 260 nm;

[0018] The material of the dielectric layer is SiO2.

[0019] To achieve the object of the present invention, a second aspect provides a method for manufacturing an antimonide single-mode photonic crystal microcavity laser for manufacturing an antimonide single-mode photonic crystal microcavity laser described in the above technical solution. The manufacturing method includes:

[0020] S1. Epitaxially grow an N-type buffer layer, an N-type confinement layer, a quantum well active layer, a P-type confinement layer, and a P-type cap layer on an N-type substrate of GaSb material in sequence;

[0021] S2. Deposit silicon oxide thick enough by chemical vapor deposition as a hard mask for etching the photonic crystal pattern. Using electron beam lithography, after photoresist spin coating, exposure, and development, obtain the photoresist pattern of the photonic crystal. Then, first use reactive ion etching technology to etch the hard mask, transfer the photoresist pattern of the photonic crystal onto the silicon oxide, and then remove the remaining photoresist. Finally, use inductively coupled plasma technology to etch the bulk material to the interface between the active layer and the P-type confinement layer, thereby forming the photonic crystal;

[0022] S3. First, form a pattern by maskless ultraviolet exposure, and then use inductively coupled plasma technology to etch out the groove and ridge waveguide structure, and then remove the remaining photoresist;

[0023] S4. Deposit silicon oxide on the photonic crystal and the ridge waveguide by chemical vapor deposition. Part of the silicon oxide will enter the internal etching holes of the photonic crystal to prevent metal from entering the photonic crystal during electrode preparation, which may cause additional losses. Another part of the silicon oxide will adhere to the sidewalls of the ridge waveguide to prevent subsequent etching from damaging the sidewalls of the ridge waveguide and causing additional losses;

[0024] S5. First, use maskless ultraviolet exposure, and then use reactive ion etching technology to remove part of the silicon oxide in the center area of the ridge waveguide to prepare for the preparation of the electrode. The etching rate of the silicon oxide in the air holes is lower than that of the silicon oxide outside the air holes. Therefore, it can ensure that the silicon oxide outside the air holes is removed while the silicon oxide in the air holes is basically not affected;

[0025] S6. First, use maskless ultraviolet exposure, and then evaporate the P-metal layer on the upper surface of the device to prepare a patterned P-type electrode using the lift-off process;

[0026] S7. Thin and polish the back of the substrate, and then evaporate the N-type metal layer on the back of the substrate to prepare the N-type electrode;

[0027] S8. Anneal, cleave, coat, and package the sample to prepare the antimonide single-mode photonic crystal microcavity laser.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] By coupling the photonic crystal to the ridge waveguide of the antimonide semiconductor laser by etching method, the present invention effectively improves the spectral characteristics of single longitudinal mode narrow linewidth and wavelength stability of the antimonide semiconductor laser. At the same time, in the preparation method of the photonic crystal, only electron beam lithography and high-efficiency dry etching processes are required to achieve it. Its preparation can be carried out synchronously with the preparation of the ridge waveguide. In the whole process flow, only the epitaxial growth technology is used at the very beginning to grow the epitaxial structure, avoiding the process steps of secondary epitaxy and the losses caused by secondary epitaxial growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 FIG. 1 is a schematic diagram of an antimonide single-mode photonic crystal microcavity laser according to the invention of the present application;

[0031] Figure 2 FIG. 2 is a schematic diagram of the steps of a method for fabricating an antimonide single-mode photonic crystal microcavity laser according to the invention of the present application.

[0032] DESCRIPTION OF THE REFERENCE NUMERALS:

[0033] 1. N-type electrode; 2. N-type substrate; 3. N-type buffer layer; 4. N-type optical confinement layer; 5. Quantum well active layer; 6. P-type optical confinement layer; 7. P-type capping layer; 8. Dielectric layer; 9. P-type electrode; 10. Ridge waveguide; 11. Photonic crystal. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The following further describes in detail the specific embodiments of the present invention in conjunction with the drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0035] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0036] Example 1

[0037] Please refer to Figure 1 , the present invention provides an antimonide single-mode photonic crystal microcavity laser, comprising: an N-type electrode, an N-type substrate, an N-type buffer layer, an N-type optical confinement layer, a quantum well active layer, a P-type optical confinement layer, a P-type capping layer, a dielectric layer, and a P-type electrode, which are sequentially arranged from bottom to top. Two bosses are provided on the upper part of the P-type electrode, and a ridge waveguide is arranged between the two bosses. A groove is arranged between the boss and the ridge waveguide, and the depth of the groove extends downward into the interior of the P-type capping layer but does not reach the P-type optical confinement layer. A photonic crystal is arranged on the ridge waveguide, and the photonic crystal is a periodic air hole arrangement structure along the direction of the ridge waveguide.

[0038] The substrate material is GaSb, and the N-type buffer layer material is GaSb; the thickness of the N-type buffer layer is 356 - 376 nm, fabricated on the N-type substrate; the N-type optical confinement layer material is AlGaAsSb, and the thickness of the N-type optical confinement layer is 1 - 3 μm, fabricated on the N-type buffer layer for regulating the optical field; the active layer is a quantum well structure composed of AlGaAsSb / InGaAsSb materials, fabricated on the N-type optical confinement layer, and the thickness of the quantum well active layer is 550 - 570 nm for achieving optical gain; the P-type optical confinement layer material is AlGaAsSb, and the thickness of the P-type optical confinement layer is 1 - 3 μm, fabricated on the active region for regulating the optical field; the P-type cap layer material is GaSb, and the thickness of the P-type cap layer is 240 - 260 nm, fabricated on the P-type optical confinement layer; the dielectric layer material is SiO2, formed on the surface of the ridge waveguide and the photonic crystal; the dielectric layer on the ridge waveguide needs to be removed for current injection; the P-type electrode is formed on the ridge waveguide and the dielectric layer, and the material of the P-type electrode is at least one of Pd, Pt, Au, and Zn; the N-type electrode is formed under the N-type substrate, and the material of the N-type electrode is at least one of AuGe, Ni, Au, Ti, and Pt.

[0039] The ridge waveguide is fabricated on the surface of the above epitaxial structure, formed by ordinary contact lithography and dry etching. This structure can prevent the carriers injected from the surface of the wide ridge waveguide from diffusing to both sides, and a refractive index difference is formed between the etched groove region and the ridge waveguide, so that as many carriers as possible reach the active region; the photonic crystal is fabricated on the ridge waveguide, also formed by ordinary contact lithography and dry etching, and its preparation can be completed in the same step as the ridge waveguide, used for selecting the optical wavelength to achieve single-mode narrow linewidth wavelength stable output. In addition, during etching, the depth of the groove part should be etched into the interior of the P-type cap layer, but the etching depth cannot reach the P-type optical confinement layer to ensure that the laser operates in single mode in the horizontal direction; the etching depth of the photonic crystal is the same as that of the groove.

[0040] Embodiment 2

[0041] This Embodiment 2 is based on Embodiment 1, further explains the structure of the photonic crystal in Embodiment 1 and experimentally verifies the progressiveness of the laser of the present invention.

[0042] The definition of the photonic crystal in the present invention is a periodic air hole arrangement structure with a refractive index difference. Considering that circular patterns are relatively easy to fabricate in steps such as exposure and etching, and the refractive index of air is naturally low, a method of directly etching circular air holes (refractive index of 1) in the ridge waveguide (high refractive index) is adopted to create the refractive index difference. And the circular air holes are only periodic in one dimension (along the ridge waveguide direction), so the photonic crystal designed in the present invention is a one-dimensional photonic crystal.

[0043] The one-dimensional photonic crystal with a periodic air hole arrangement structure is a defective photonic crystal. By introducing a defect at the center of the photonic crystal waveguide, that is, increasing the distance between two adjacent air holes in the central area, the distance between two adjacent air holes in the center of the photonic crystal is a first distance, and the distance between any other non-central two adjacent air holes in the photonic crystal is a second distance, and the first distance is greater than the second distance. The difference between the first distance and the second distance is within a period length of an original photonic crystal, and the original photonic crystal is a photonic crystal in which the distance between any two adjacent air holes is the second distance. The translational symmetry of the photonic crystal is destroyed to form a one-dimensional photonic crystal waveguide microcavity structure, so that only light waves with wavelengths that meet specific resonance conditions can be restricted to continuously resonate in the microcavity. The wavelength of the restricted light wave is determined by the size of the air hole and the distance between the holes. The relevant parameters of the photonic crystal that meet the requirements are calculated according to the central wavelength of the laser, and the resonance of the light wave can be achieved. The restricted wavelength of the light wave is determined by the size of the air hole and the distance between the holes. According to the center wavelength of the laser, the dispersion relation of the photonic crystal can be calculated by the finite difference time domain method (FDTD). By adjusting the geometric parameters of the photonic crystal, such as the period and the size of the etched hole, the center wavelength of the laser can be adjusted to the bandgap of the photonic crystal (obtained from the dispersion relation). In this way, the light waves in the bandgap cannot exist inside the photonic crystal and will be perfectly reflected. The light field is therefore localized in the defect and resonance is achieved. Since the photonic crystal can perfectly reflect the photons in the bandgap, the photonic crystal defect cavity (microcavity) has stronger confinement and smaller mode volume than the resonant cavity formed by the traditional Bragg grating, and therefore has a higher quality factor. Compared with the coupling grating structure on the ridge waveguide, the resonance efficiency of the laser of the present invention is higher.

[0044] Since the photonic crystal designed in the present invention has periodicity only in the direction along the ridge waveguide, it only has a limiting effect on the light field in this direction. Therefore, it is necessary to etch grooves on both sides of the ridge waveguide to limit the injection of carriers and photons, so as to couple the mode and the photonic crystal to the highest degree.

[0045] like Figure 1As shown, the N-type substrate material of the laser prepared in this Example 2 is GaSb, and the N-type buffer layer material is GaSb with a thickness of 366 nm, which is fabricated on the N-type substrate; the N-type optical confinement layer material is AlGaAsSb with a thickness of 2 μm, which is fabricated on the N-type buffer layer for the regulation of the optical field; the active region is a quantum well structure composed of AlGaAsSb / InGaAsSb materials, which is fabricated on the N-type optical confinement layer for achieving optical gain, with an overall thickness of 560 nm; the P-type optical confinement layer material is AlGaAsSb with a thickness of 2 μm, which is fabricated on the active region for the confinement of the optical field; the P-type capping layer material is GaSb with a thickness of 250 nm, which is fabricated on the P-type optical confinement layer; the dielectric layer material is SiO2, which is formed on the surface of the ridge waveguide and the photonic crystal. The dielectric layer on the ridge waveguide needs to be removed for current injection; the P-type electrode is formed on the ridge waveguide and the dielectric layer, and the material used is Au; the N-type electrode is formed under the N-type substrate, and the material used is Au.

[0046] The lasing wavelength of traditional antimonide semiconductor lasers is determined by the bandgap width of the active region. Generally, the spectral width is greater than 1 nm, and the drift speed of its wavelength with the working current is relatively large, resulting in poor wavelength stability. However, as measured in this Example 2, the spectral linewidth of a narrow ridge stripe antimonide semiconductor laser without photonic crystal coupling is 1.05 nm, and the drift speed of the wavelength with the current is 12.9 nm / A. After coupling the above-mentioned photonic crystal on the ridge waveguide of the semiconductor laser prepared by the solution of the present invention, the spectral linewidth is reduced to 0.24 nm, and the drift speed of the wavelength with the current is reduced to 1.035 nm / A, effectively realizing laser output with a narrow spectrum and high wavelength stability.

[0047] Example 3

[0048] As Figure 2 shown, based on Example 1 and Example 2, this Example 3 provides a preparation method for an antimonide single-mode photonic crystal microcavity laser for preparing an antimonide single-mode photonic crystal microcavity laser described in the above Example 1 and Example 2. The preparation method includes:

[0049] S1. Epitaxially grow an N-type buffer layer, an N-type confinement layer, a quantum well active layer, a P-type confinement layer, and a P-type capping layer in sequence on an N-type substrate of GaSb material;

[0050] S2. Deposit a thick enough silicon oxide dielectric layer as a hard mask for etching the photonic crystal pattern by chemical vapor deposition. Using electron beam exposure lithography, after photoresist spin coating, exposure, and development, a photoresist pattern of the photonic crystal is obtained. Then, first use reactive ion etching technology to etch the hard mask, transfer the photoresist pattern of the photonic crystal to the silicon oxide, then remove the remaining photoresist, and finally use inductively coupled plasma technology to etch the bulk material to the interface between the active layer and the P-type confinement layer to form the photonic crystal;

[0051] S3. First, form a pattern by maskless ultraviolet exposure, then use inductively coupled plasma technology to etch out grooves and ridge waveguide structures, and then remove the remaining photoresist;

[0052] S4. Use chemical vapor deposition to deposit silicon oxide on the photonic crystal and the ridge waveguide. A part of the silicon oxide will enter the etching holes of the photonic crystal to prevent metal from entering the photonic crystal during electrode preparation, which may cause additional losses. Another part of the silicon oxide will adhere to the sidewalls of the ridge waveguide to prevent subsequent etching from damaging the sidewalls of the ridge waveguide, thereby avoiding additional losses;

[0053] S5. First, use maskless ultraviolet exposure, and then use reactive ion etching technology to remove a part of the silicon oxide in the center area of the ridge waveguide to prepare for the preparation of the electrode. The etching rate of silicon oxide in the air holes is lower than that of silicon oxide outside the air holes. Therefore, it can ensure that the silicon oxide outside the air holes is removed while the silicon oxide in the air holes is basically unaffected;

[0054] S6. First, use maskless ultraviolet exposure, and then evaporate the P metal layer on the upper surface of the device to prepare a patterned P-type electrode using the lift-off process;

[0055] S7. Thin and polish the back of the substrate, and then evaporate the N-type metal layer on the back of the substrate to prepare the N-type electrode;

[0056] S8. Anneal, cleave, coat, and package the sample to prepare the antimonide single-mode photonic crystal microcavity laser described above.

[0057] In the laser preparation process proposed in this Embodiment 3, the preparation of the two structures of the photonic crystal and the ridge waveguide is mainly carried out. The preparation of the photonic crystal can be completed in the same step as the ridge waveguide (that is, steps S2 and S3 can be synchronized). The method of the present invention can achieve single-mode narrow linewidth output only by one epitaxy and ordinary lithography technology, avoiding the use of secondary epitaxy and high-precision lithography technology in traditional laser devices. The preparation of the photonic crystal requires the use of chemical vapor deposition (CVD), electron beam lithography (EBL), reactive ion etching (RIE), and inductively coupled plasma etching (ICP); the preparation of the ridge waveguide requires the use of maskless ultraviolet lithography and inductively coupled plasma etching. Since only epitaxial growth technology is used at the very beginning of the entire process flow to grow the epitaxial structure, avoiding the process steps of secondary epitaxy, on the one hand, the entire process flow is greatly simplified, and on the other hand, the additional losses caused by secondary epitaxy are also avoided.

[0058] As described in the above embodiments, the present invention couples a defective one-dimensional photonic crystal on the ridge waveguide of a narrow ridge strip antimony-based semiconductor, so that light waves of a specific wavelength are confined inside the waveguide to complete resonance, thereby realizing single longitudinal mode output of the laser. Compared with coupling a grating structure on the ridge waveguide, the resonance efficiency of this scheme is higher. By coupling a photonic crystal on the ridge waveguide, the method of the present invention can effectively reduce the spectral width of the output beam of the device and improve the wavelength stability of the device. Conventional single-mode antimony-based semiconductor lasers with wavelength stability characteristics usually require secondary epitaxy and electron beam lithography techniques. However, the method of the present invention can achieve single-mode narrow linewidth output only by one epitaxy plus ordinary photolithography techniques, avoiding the use of secondary epitaxy and high-precision lithography techniques for traditional laser devices, with simple preparation and low process cost.

[0059] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An antimonide single-mode photonic crystal microcavity laser, characterized in that: The invention comprises an N-type electrode, an N-type substrate, an N-type buffer layer, an N-type light confinement layer, a quantum well active layer, a P-type light confinement layer, a P-type cover layer, a dielectric layer and a P-type electrode which are arranged in sequence from bottom to top. Two bosses are arranged on the upper part of the P-type electrode, a ridge waveguide is arranged between the two bosses, a groove is formed between the bosses and the ridge waveguide, the depth of the groove reaches the inside of the P-type cover layer but does not touch the P-type light confinement layer, a photonic crystal is arranged on the ridge waveguide, and the photonic crystal is a periodic air hole arrangement structure along the ridge waveguide direction.

2. The antimonide single-mode photonic crystal microcavity laser according to claim 1, characterized in that: The distance between two adjacent air holes in the center of the photonic crystal is a first distance, and the distance between any other non-central two adjacent air holes in the photonic crystal is a second distance, and the first distance is greater than the second distance.

3. The antimonide single-mode photonic crystal microcavity laser according to claim 2, characterized in that: The difference between the first distance and the second distance is within a period length of an original photonic crystal, and the original photonic crystal is a photonic crystal in which the distance between any two adjacent air holes is the second distance.

4. An antimonide single-mode photonic crystal microcavity laser according to any one of claims 2 or 3, characterized in that: The air hole is a circular air hole.

5. The antimonide single-mode photonic crystal microcavity laser according to claim 1, characterized in that: The light refractive index of the air hole is 1, and the light refractive index of the ridge waveguide is greater than the light refractive index of the photonic crystal.

6. The antimonide single-mode photonic crystal microcavity laser according to claim 1, characterized in that: The photonic crystal and the groove are formed by etching, and the etching depth of the photonic crystal is equal to the etching depth of the groove.

7. The antimonide single-mode photonic crystal microcavity laser according to claim 1, characterized in that: The material of the N-type electrode is at least one of AuGe, Ni, Au, Ti, and Pt.

8. The antimonide single-mode photonic crystal microcavity laser according to claim 1, characterized in that: The material of the P-type electrode is at least one of Pd, Pt, Au, and Zn.

9. The antimonide single-mode photonic crystal microcavity laser according to claim 1, characterized in that: The material of the N-type substrate is GaSb; The material of the N-type buffer layer is GaSb, and the thickness of the N-type buffer layer is 356-376nm; The material of the N-type light confinement layer is AlGaAsSb, and the thickness of the N-type light confinement layer is 1-3 μm; The material of the quantum well active layer is at least one of AlGaAsSb and InGaAsSb, and the thickness of the quantum well active layer is 550-570nm; The material of the P-type light confinement layer is AlGaAsSb, and the thickness of the P-type light confinement layer is 1-3 μm; The material of the P-type cap layer is GaSb, and the thickness of the P-type cap layer is 240-260nm; The material of the dielectric layer is SiO2.

10. A method for preparing an antimonide single-mode photonic crystal microcavity laser, used for preparing an antimonide single-mode photonic crystal microcavity laser according to any one of claims 1 to 9, characterized in that: The preparation method comprises: S1. epitaxially growing an N-type buffer layer, an N-type confinement layer, a quantum well active layer, a P-type confinement layer and a P-type cap layer on an N-type substrate of GaSb material in sequence; S2, using chemical vapor deposition to deposit a sufficiently thick silicon oxide dielectric layer as a hard mask for etching the photonic crystal pattern, using electron beam exposure photolithography, after photoresist spin coating, exposure, and development, a photoresist pattern of the photonic crystal is obtained, and then the hard mask is first etched using reactive ion etching technology, and the photoresist pattern of the photonic crystal is transferred to the silicon oxide, and then the residual photoresist is removed, and finally the bulk material is etched to the interface between the active layer and the P-type confinement layer using inductively coupled plasma technology, thereby forming a photonic crystal; S3, first use maskless ultraviolet exposure to form a pattern, then use inductively coupled plasma technology to etch out the groove and ridge waveguide structure, and then remove the residual photoresist; S4. Use chemical vapor deposition to deposit silicon oxide on the photonic crystal and ridge waveguide. A portion of the silicon oxide will enter the photonic crystal etching hole to prevent metal from entering the photonic crystal when preparing the electrode, causing additional losses. Another portion of the silicon oxide will adhere to the side wall of the ridge waveguide to prevent subsequent etching from damaging the ridge waveguide side wall and causing additional losses. S5. First, use maskless UV exposure, and then use reactive ion etching technology to remove the silicon oxide in a part of the center area of ​​the ridge waveguide to prepare for the preparation of the electrode. The etching rate of the silicon oxide in the air hole is lower than the etching rate of the silicon oxide outside the air hole. Therefore, it can be ensured that the silicon oxide outside the air hole is removed while the silicon oxide in the air hole is basically not affected; S6, first use maskless UV exposure, and then evaporate a P metal layer on the upper surface of the device to prepare a patterned P-type electrode using a lift-off process; S7, thinning and polishing the back side of the substrate, and then evaporating an N-type metal layer on the back side of the substrate to prepare an N-type electrode; S8. Annealing, cleaving, coating and packaging the sample to prepare the antimonide single-mode photonic crystal microcavity laser.

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