Semiconductor-pumped quantum dot green laser and manufacturing method thereof

Abstract

The application relates to a kind of semiconductor-pumped quantum dot green light laser and its manufacturing method, belong to the technical field of laser, the present application is coupled to the waveguide surface by grating structure and is outputted to blue light, blue light is irradiated into the polymer waveguide containing green quantum dot material, and the polymer waveguide resonant cavity is formed in the form of photoetching, finally, the film is formed on the both ends of polymer waveguide to form green light laser, realize the laser output of wavelength 520-540nm.The technology relies on conventional semiconductor laser process, only the spin-coating and photoetching step of green quantum dot polymer containing on P face metal is increased, mass production can be realized, and the cost of laser can be effectively reduced, and green light laser output can be realized without subsequent optical crystal and frequency doubling crystal.

Description

Technical Field

[0001] This invention relates to a semiconductor-pumped quantum dot green laser and its fabrication method, belonging to the field of laser technology. Background Technology

[0002] Visible light semiconductor lasers are widely used in construction, laser displays, industrial applications, and medical devices due to their high efficiency, small size, and high reliability. Among them, green light semiconductor lasers, used for indication, are widely used in outdoor laser indicators, ranging markers, laser sensors, and medical devices because of their excellent photoelectric conversion efficiency and human eye sensitivity. However, the materials used in green light semiconductor lasers are currently mainly GaN / InGaN compound materials, which have high band gaps. Even the lowest tunable band gap is still higher than the 2.33 eV of the 532nm positive green band. This causes the output wavelength of these semiconductor lasers to deviate from 532nm, mainly concentrated between 510nm and 520nm, resulting in significant color deviation and severely limiting their applications. In addition, there are currently technical solutions and systems that generate 1064nm laser by pumping crystal materials with semiconductor lasers, and then generate 532nm laser by frequency doubling with nonlinear crystals. However, this system includes semiconductor lasers and crystals, has a complex optical path, high cost, and large size, which cannot meet the needs of large-scale industrial production. This seriously affects the production and use of green semi-solar lasers and results in high equipment costs.

[0003] To address the above issues, the main existing solutions are as follows: First, by developing and doping compound semiconductor materials and their structures, the band gap of GaN and InGaN compound materials can be reduced as much as possible. Through material doping and laser structure design, the wavelength can be made as close to 532nm as possible. However, the current challenge is that the physical mechanism is already approaching the theoretical limits of the materials, making implementation difficult. Doping also significantly reduces the quality of material growth, and the introduction of defects causes a substantial decrease in chip output power and efficiency, thus negating its application value. The second approach is to integrate optical components such as semiconductor pumps, crystals, and nonlinear crystals to reduce the size of the green laser. However, this approach still relies on optical system assembly technology and cannot achieve chip-level mass production and large-scale manufacturing, resulting in limited cost control. Summary of the Invention

[0004] This invention provides a semiconductor-pumped quantum dot green laser and its fabrication method. Based on a conventional blue semiconductor laser, green quantum dot material is uniformly mixed into an organic liquid material and then photolithographically coated onto the surface of the blue semiconductor laser. A surface grating is then placed on the surface of the blue laser to direct the laser beam along the laser surface, which enters a polymer waveguide layer on the surface, exciting the green quantum dots mixed within the waveguide layer. Optical coatings are then applied to both ends of the polymer waveguide layer to create a resonant cavity, ultimately achieving green light output.

[0005] The technical solution of the present invention is as follows:

[0006] A semiconductor-pumped quantum dot green laser comprises, from bottom to top, a substrate, an N-confinement layer, an N-waveguide layer, a quantum well active layer, a P-waveguide layer, and a P-confinement layer;

[0007] The P-confinement layer is partially removed by etching to form a shoulder, and a ridge waveguide is formed between the two shoulders. An ohmic contact layer is covered on top of the ridge waveguide, and an insulating layer is covered on top and sides of the shoulders. The insulating layer has an opening at the ridge waveguide, and the edge of the opening is a certain distance away from the edge of the ridge waveguide. At the opening of the insulating layer above the ridge waveguide, the P-plane metal layer and the ohmic contact layer are in contact, so that current is injected only into the ohmic contact layer above the ridge waveguide.

[0008] A grating is disposed above the ridge waveguide, and the length of the grating is the same as the length of the ridge waveguide. A P-plane metal layer is covered above the insulating layer, the P-confining layer and the ohmic contact layer. There is a gap region in the P-plane metal layer in the ridge waveguide extension direction. The length of the gap region is less than the length of the ridge waveguide and the width of the gap region is less than the width of the ridge waveguide. A quantum dot light-emitting layer is disposed above the grating, and the width of the quantum dot light-emitting layer is the same as that of the ridge waveguide.

[0009] The substrate is thinned at the bottom and then an N-side metal layer is provided.

[0010] Preferably, the distance between the edge of the opening and the edge of the ridge waveguide is less than 5 μm.

[0011] Preferably, the ridge waveguide width is 2μm-200μm and the chip thickness is 50μm-200μm, with a preferred ridge waveguide width of 20μm and a chip thickness of 120μm.

[0012] Preferably, the upper part of the ridge waveguide is etched to form an equally spaced concave-convex periodic structure to form a grating. The concave part is obtained by etching the ohmic contact layer and part of the P-confinement layer on the upper part of the ridge waveguide, with an etching depth of 10nm-1000nm. The proportion of concave-convex structures within the grating period is 50%, that is, the length of the concave-convex structures is the same.

[0013] The grating structure satisfies the grating diffraction formula:

[0014] m×λ c =n neff ×Λ

[0015] Where m is a positive integer, λ c As the center wavelength of reflection, in this invention, λ c 300-500nm; n neff Λ represents the effective refractive index of the grating material, which typically ranges from 1.4 to 3.4 depending on the depth. Λ represents the period of the grating's concave-convex structure. In this invention, when the period m is an even number, the grating period is calculated based on the center wavelength. Preferably, according to this invention, Λ is 120-300 nm.

[0016] The main function of the grating is to couple the laser output from the ridge waveguide to a plane perpendicular to the ridge waveguide, and then into the quantum dot light-emitting layer above.

[0017] Preferably, the quantum dot luminescent layer is prepared by quantum dots and liquid polymer, with the mass ratio of quantum dots to liquid polymer being 0.1%-5%. The quantum dots are selected mainly based on the position of the peak of their fluorescence emission spectrum, with the emission peak of the quantum dots being 520nm-540nm and the viscosity of the liquid polymer being 10cp-100cp.

[0018] Preferably, the mass ratio of quantum dots to liquid polymer is 1%.

[0019] Preferably, the diameter of the quantum dots is 2nm-20nm, including but not limited to: InAs, InSb, InP, and GaAs in the III-V group material system; CdS, CdSe, ZnSeTe, ZnSeS, ZnS, and HgTe in the II-VI group material system; and SnTe, PbS, and PbSe in the IV-VI group material system.

[0020] To ensure that liquid polymers have the ability to transmit light within the required laser wavelength range, liquid polymers include, but are not limited to, PMMA (polymethyl methacrylate), PSU (polysulfone), PET (polyethylene terephthalate), COC (cyclic olefin copolymer), TPX (poly4-methylpentene-1 monomer), PS (phosphatidylserine), NAS (N-acryloyloxysuccinimide), and ADC (allyl diethylene glycol carbonate).

[0021] A method for fabricating the above-mentioned semiconductor-pumped quantum dot green laser includes the following steps:

[0022] (1) An N-confined layer, an N-waveguide layer, a quantum well active layer, a P-waveguide layer and a P-confined layer were sequentially grown on the substrate using the MOCVD method.

[0023] (2) After photolithography and development, ridge waveguides and shoulders are prepared at specific locations using etching technology, and an ohmic contact layer is prepared above the ridge waveguides;

[0024] (3) Silicon dioxide is grown using PECVD technology to form an insulating layer, and the insulating layer above and on one side of the ridge waveguide is removed by photolithography, etching or stripping. The distance between the edge of the insulating layer and the edge of the ridge waveguide is less than 5 μm.

[0025] (4) A grating is fabricated on the upper part of the ridge waveguide by photolithography and etching, and the proportion of concave and convex structures in the grating period is 50%.

[0026] (5) The P-side metal layer is prepared by vapor deposition. There is a void region in the middle region of the P-side metal layer in the elongation direction of the ridge waveguide. The length of the void region is less than the length of the ridge waveguide, and the width is less than the width of the ridge waveguide. The width and length of the void region account for 50% of the width and length of the ridge waveguide, respectively.

[0027] (6) Preparation of quantum dot light-emitting layer: Quantum dots are mixed with liquid polymer evenly, stirred and ultrasonically treated to form liquid mixture, and the liquid mixture is spin-coated onto the entire P-side metal layer;

[0028] (7) After photolithography, only the quantum dot light-emitting layer above the ridge waveguide is retained to form a polymer waveguide, and the width of the polymer waveguide is the same as the width of the ridge waveguide.

[0029] (8) The substrate is thinned and then an N-plane metal layer is prepared by vapor deposition. After alloying, the laser cavity surface is cleaved and a high-reflection film is finally deposited on the laser cavity surface to form a semiconductor laser. A green high-reflection film and a partial reflection film are deposited at both ends of the polymer waveguide to finally prepare a semiconductor-pumped quantum dot green laser. The high-reflection film refers to a film with a reflectivity higher than 95%, and the partial reflection film refers to a film with a reflectivity lower than 95%.

[0030] Preferably, the preparation process of the quantum dot light-emitting layer in step (6) is as follows:

[0031] Quantum dots are placed in a liquid polymer and ultrasonically treated while stirring to uniformly disperse the quantum dots and form a stable polymer suspension. The laser cavity surface is perpendicular to the plane of the ridge waveguide. The liquid polymer mixed with quantum dots is dispensed and spin-coated to form a uniform polymer liquid film with a thickness of 0.5-10 μm above the laser ridge waveguide. Then, the polymer liquid film is cured.

[0032] Preferably, a spotlight emitting ultraviolet or blue light in the wavelength range of 300nm-450nm is used for photocuring, or a hot oven with a temperature range of 100℃-450℃ is used for heat curing.

[0033] For any technical solutions not described in detail or limited above, reference shall be made to existing technologies.

[0034] The beneficial effects of this invention are as follows:

[0035] This invention, based on a conventional edge-emitting blue semiconductor laser, couples blue light to a waveguide surface via a grating structure for output. The blue light then illuminates a polymer waveguide containing green quantum dot material, and a polymer waveguide resonant cavity is formed through photolithography. Finally, a green laser is formed by coating both ends of the polymer waveguide, outputting green laser light. This invention effectively overcomes the wavelength limitations of existing GaN materials, achieving laser output with wavelengths of 520-540 nm by selecting the quantum dot diameter and material. Moreover, this technology relies on conventional semiconductor laser manufacturing processes, adding only polymer spin-coating and photolithography steps to the metal, enabling mass production while effectively reducing laser costs. It eliminates the need for subsequent solid-state laser systems composed of optical crystals and frequency-doubling crystals, significantly lowering the overall cost of the laser. Attached Figure Description

[0036] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0037] Figure 1 This is a conventional edge-emitting blue semiconductor laser that has had its P-side and N-side metal layers removed from existing technologies.

[0038] Figure 2 This is a conventional side-emitting blue semiconductor laser in the existing technology;

[0039] Figure 3 This is a schematic diagram of the semiconductor-pumped quantum dot green laser structure after removing the P-side metal layer, N-side metal layer, insulating layer and quantum dot light-emitting layer of the present invention.

[0040] Figure 4 This is a schematic diagram of the semiconductor-pumped quantum dot green laser structure after removing the quantum dot light-emitting layer of the present invention.

[0041] Figure 5 This is a schematic diagram of the semiconductor-pumped quantum dot green laser structure of the present invention.

[0042] In the figure: 1. GaAs substrate, 2. N-confinement layer, 3. N-waveguide layer, 4. Quantum well active layer, 5. P-waveguide layer, 6. P-confinement layer, 7. Shoulder, 8. Shoulder groove, 9. Ridge waveguide, 10. Ohmic contact layer, 11. Insulating layer, 12. P-plane metal layer, 13. N-plane metal layer, 14. Grating, 15. Quantum dot light-emitting layer, 16. Quantum dot. Detailed Implementation

[0043] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this invention are clearly and completely described, but are not limited thereto. Any aspects not described in detail in this invention are based on conventional techniques in the art.

[0044] Example 1

[0045] A semiconductor-pumped quantum dot green laser, such as Figures 3-5 As shown, from bottom to top, it includes GaAs substrate 1, N confinement layer 2, N waveguide layer 3, quantum well active layer 4, P waveguide layer 5 and P confinement layer 6.

[0046] The P-confinement layer 6 is partially removed by etching to form a shoulder 7. A ridge waveguide 9 is formed between the two shoulders. A shoulder groove 8 is formed between the shoulder 7 and the ridge waveguide 9. An ohmic contact layer 10 is covered above the ridge waveguide 9. An insulating layer 11 is covered above and on the sides of the shoulder 7. The insulating layer 11 has an opening at the ridge waveguide, and the edge of the opening is a certain distance away from the edge of the ridge waveguide. At the opening of the insulating layer above the ridge waveguide 9, the P-side metal layer 12 and the ohmic contact layer are in contact, so that current is injected only into the ohmic contact layer above the ridge waveguide.

[0047] A grating 14 is disposed above the ridge waveguide 9, and the length of the grating 14 is the same as the length of the ridge waveguide 9. A P-plane metal layer 12 is covered above the insulating layer 11, the P-confining layer 6 and the ohmic contact layer 10. There is a gap region in the P-plane metal layer 12 in the elongation direction of the ridge waveguide. The length of the gap region is less than the length of the ridge waveguide and the width of the gap region is less than the width of the ridge waveguide. A quantum dot light-emitting layer 15 is disposed above the grating, and the width of the quantum dot light-emitting layer 15 is the same as that of the ridge waveguide 9.

[0048] An N-plane metal layer 13 is formed on the bottom of the GaAs substrate 1 after thinning.

[0049] Example 2

[0050] A semiconductor-pumped quantum dot green laser, as described in Example 1, except that the distance between the opening edge and the ridge waveguide edge is less than 5 μm.

[0051] Example 3

[0052] A semiconductor-pumped quantum dot green laser, as described in Example 2, except that the ridge waveguide width is 20 μm and the chip thickness is 120 μm.

[0053] Example 4

[0054] A semiconductor-pumped quantum dot green laser, as described in Example 3, differs in that an equally spaced concave-convex periodic structure is etched on the upper part of the ridge waveguide to form a grating 14. The recessed portion is obtained by etching the ohmic contact layer 10 and part of the P-confining layer 6 on the upper part of the ridge waveguide, with an etching depth of 10nm-1000nm. The proportion of concave-convex structures within the grating period is 50%, that is, the length of the concave-convex structures is the same.

[0055] The grating structure satisfies the grating diffraction formula:

[0056] m×λ c =n neff ×Λ

[0057] Where m is a positive integer, λ c As the center wavelength of reflection, in this invention, λ c 300-500nm; n neff Λ represents the effective refractive index of the grating material, which typically ranges from 1.4 to 3.4 depending on the depth. Λ represents the period of the grating's concave-convex structure. In this invention, when the period m is an even number, the grating period is calculated based on the center wavelength. Preferably, according to this invention, Λ is 120-300 nm.

[0058] The main function of the grating is to couple the laser output from the ridge waveguide to a plane perpendicular to the ridge waveguide, and then into the quantum dot light-emitting layer above.

[0059] Example 5

[0060] A semiconductor-pumped quantum dot green laser, as described in Example 4, differs in that the quantum dot emitting layer is prepared from quantum dots 16 and a liquid polymer, with a mass ratio of quantum dots 16 to liquid polymer of 1%. The quantum dots are selected mainly based on the position of their fluorescence emission spectrum peaks, with the emission peaks of the quantum dots in the range of 520 nm to 540 nm, and the viscosity of the liquid polymer is 10 cp to 100 cp.

[0061] Quantum dot 16 has a diameter of 2nm-20nm and belongs to InAs in the III-V group of materials.

[0062] To ensure that the liquid polymer has the ability to transmit light within the required laser wavelength range, the liquid polymer is PMMA (polymethyl methacrylate).

[0063] This invention, based on a conventional side-emitting blue semiconductor laser, such as... Figure 1 , Figure 2As shown, blue light is coupled to the waveguide surface through a grating structure for output. The blue light irradiates the polymer waveguide containing green quantum dot material and forms a polymer waveguide resonant cavity through photolithography. Finally, a green laser is formed by coating both ends of the polymer waveguide and outputs green laser light.

[0064] Example 6

[0065] A method for fabricating a semiconductor-pumped quantum dot green laser according to Embodiment 5 includes the following steps:

[0066] (1) An N-confining layer 2, an N-waveguide layer 3, a quantum well active layer 4, a P-waveguide layer 5 and a P-confining layer 6 were sequentially grown on a GaAs substrate 1 using the MOCVD method.

[0067] (2) After photolithography and development, ridge waveguide 9 and shoulder 7 are prepared at specific locations using etching technology, and ohmic contact layer 10 is prepared above ridge waveguide 9.

[0068] (3) Silicon dioxide is grown using PECVD technology to form an insulating layer 11, and the insulating layer above and on one side of the ridge waveguide is removed by photolithography, etching or stripping. The distance between the edge of the insulating layer and the edge of the ridge waveguide is less than 5 μm.

[0069] (4) A grating 14 is fabricated on the upper part of the ridge waveguide by photolithography and etching. The proportion of concave and convex structures in the period of the grating 14 is 50%.

[0070] (5) The P-side metal layer 12 is prepared by vapor deposition. There is a void region in the middle region of the P-side metal layer 12 in the elongation direction of the ridge waveguide. The length of the void region is less than the length of the ridge waveguide, and the width is less than the width of the ridge waveguide. The width and length of the void region account for 50% of the width and length of the ridge waveguide, respectively.

[0071] (6) Preparation of quantum dot light-emitting layer 15: Quantum dots 16 are mixed with liquid polymer evenly, stirred and ultrasonically treated to form a liquid mixture, and the liquid mixture is spin-coated onto the entire P-side metal layer;

[0072] (7) After photolithography, only the quantum dot light-emitting layer 15 above the ridge waveguide is retained to form a polymer waveguide, and the width of the polymer waveguide is consistent with the width of the ridge waveguide.

[0073] (8) The substrate is thinned and then an N-plane metal layer 13 is prepared by vapor deposition. After alloying, the laser cavity surface is cleaved and a high-reflection film is finally deposited on the laser cavity surface to form a semiconductor laser. A green high-reflection film and a partial reflection film are deposited at both ends of the polymer waveguide respectively, and finally a semiconductor-pumped quantum dot green laser is prepared. The high-reflection film refers to a film with a reflectivity higher than 95%, and the partial reflection film refers to a film with a reflectivity lower than 95%.

[0074] Example 7

[0075] A method for fabricating a semiconductor-pumped quantum dot green laser according to Example 5 is as described in Example 6, except that the preparation process of the quantum dot emitting layer in step (6) is as follows:

[0076] Quantum dots 16 are placed in a liquid polymer and ultrasonically treated while stirring to uniformly disperse the quantum dots and form a stable polymer suspension. The laser cavity surface is perpendicular to the plane of the ridge waveguide. The liquid polymer mixed with quantum dots is dispensed and spin-coated to form a uniform polymer liquid film with a thickness of 0.5-10 μm above the laser ridge waveguide. Then, the polymer liquid film is cured.

[0077] Example 8

[0078] A method for fabricating a semiconductor-pumped quantum dot green laser according to Example 5 is as described in Example 7, except that a 300nm-450nm ultraviolet lamp is used for photopolymerization.

[0079] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A semiconductor-pumped quantum dot green laser, characterized in that, From bottom to top, it includes a substrate, an N-confinement layer, an N-waveguide layer, a quantum well active layer, a P-waveguide layer, and a P-confinement layer; The P-confining layer is partially removed by etching to form a shoulder. The shoulder is a cuboid protruding structure. A ridge waveguide is formed between the two shoulders. An ohmic contact layer is covered on top of the ridge waveguide. An insulating layer is covered on top and sides of the shoulders. The insulating layer has an opening at the ridge waveguide, and the edge of the opening is at a distance from the edge of the ridge waveguide. A grating is disposed on the upper part of the ridge waveguide, and the length of the grating is the same as the length of the ridge waveguide. A P-plane metal layer is covered above the insulating layer, the P-confining layer and the ohmic contact layer. There is a gap region in the P-plane metal layer in the extension direction of the ridge waveguide. The length of the gap region is less than the length of the ridge waveguide. The gap region is located in the middle region of the ridge waveguide. The width of the gap region is less than the width of the ridge waveguide. The P-plane metal layer is located on the upper part of the grating. A quantum dot light-emitting layer is disposed on the upper part of the P-plane metal layer. The width of the quantum dot light-emitting layer is the same as that of the ridge waveguide. The substrate is thinned at the bottom and then an N-side metal layer is provided. The upper part of the ridge waveguide is etched to form an equally spaced concave-convex periodic structure to form a grating. The concave portion is obtained by etching the ohmic contact layer and part of the p-confinement layer on the upper part of the ridge waveguide, with an etching depth of 10nm-1000nm; the proportion of concave-convex structure within the grating period is 50%; The quantum dot emitting layer is prepared by quantum dots and liquid polymer. The emission peak of the quantum dots is between 520nm and 540nm, and the viscosity of the liquid polymer is between 10cp and 100cp. The quantum dot emitting layer forms a polymer waveguide. A green high-reflection film and a partial reflection film are respectively deposited at both ends of the polymer waveguide, which are set as a resonant cavity to realize green light output.

2. The semiconductor-pumped quantum dot green laser according to claim 1, characterized in that, The distance between the edge of the opening and the edge of the ridge waveguide is less than 5 μm.

3. The semiconductor-pumped quantum dot green laser according to claim 1, characterized in that, The ridge waveguide has a width of 2μm-200μm and a chip thickness of 50μm-200μm.

4. The semiconductor-pumped quantum dot green laser according to claim 3, characterized in that, The diameter of quantum dots ranges from 2nm to 20nm, including: InAs, InSb, InP, and GaAs in the III-V group material system; CdS, CdSe, ZnSeTe, ZnSeS, ZnS, and HgTe in the II-VI group material system; and SnTe, PbS, and PbSe in the IV-VI group material system. Liquid polymers include polymethyl methacrylate, polysulfone, polyethylene terephthalate, cyclic olefin copolymers, poly-4-methylpentene-1 monomer, phosphatidylserine, N-acryloyloxysuccinimide, and allyl diethylene glycol carbonate.

5. A method for fabricating a semiconductor-pumped quantum dot green laser as described in claim 4, characterized in that, Includes the following steps: (1) An N-confined layer, an N-waveguide layer, a quantum well active layer, a P-waveguide layer, and a P-confined layer are sequentially grown on a substrate using the MOCVD method; (2) After photolithography and development, the ridge waveguide and shoulder are prepared by etching technology, and an ohmic contact layer is prepared on the ridge waveguide; (3) Silicon dioxide is grown using PECVD technology to form an insulating layer, and the insulating layer on the top and sides of the ridge waveguide is removed by photolithography, etching or stripping. (4) A grating is fabricated on the upper part of the ridge waveguide by photolithography and etching, with the proportion of concave and convex structures in the grating period being 50%; (5) The P-side metal layer is prepared by vapor deposition. There is a void region in the middle region of the P-side metal layer in the elongation direction of the ridge waveguide. The length of the void region is less than the length of the ridge waveguide and the width is less than the width of the ridge waveguide. (6) Preparation of quantum dot light-emitting layer: Quantum dots are mixed with liquid polymer evenly, stirred and ultrasonically treated to form liquid mixture, and the liquid mixture is spin-coated onto the entire P-side metal layer; (7) After photolithography, only the quantum dot light-emitting layer above the ridge waveguide is retained to form a polymer waveguide, and the width of the polymer waveguide is consistent with the width of the ridge waveguide; (8) The substrate is thinned and then an N-plane metal layer is prepared by vapor deposition. After alloying, the laser cavity surface is cleaved and a high-reflection film is finally deposited on the laser cavity surface to form a semiconductor laser. A green high-reflection film and a partial reflection film are deposited at both ends of the polymer waveguide to finally prepare a semiconductor-pumped quantum dot green laser.

6. The method for fabricating a semiconductor-pumped quantum dot green laser according to claim 5, characterized in that, The preparation process of the quantum dot light-emitting layer in step (6) is as follows: Quantum dots are placed in a liquid polymer and ultrasonically treated while stirring to uniformly disperse the quantum dots and form a stable polymer suspension. The laser cavity surface is perpendicular to the horizontal plane where the ridge waveguide is located. The liquid polymer mixed with quantum dots is dispensed and spin-coated to form a uniform polymer liquid film with a thickness of 0.5-10 μm above the laser ridge waveguide. Then, the polymer liquid film is cured.

7. The method for fabricating a semiconductor-pumped quantum dot green laser according to claim 6, characterized in that, Use a spotlight emitting wavelengths in the range of 300nm-450nm for photocuring, or use a hot oven with a temperature range of 100℃-450℃ for heat curing.

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