Semiconductor pumped quantum dot green laser and manufacturing method thereof

Abstract

The invention relates to a semiconductor-pumped quantum dot green laser and a manufacturing method thereof, and belongs to the technical field of lasers, blue light is coupled to the surface of a waveguide through a grating structure to be output, the blue light is irradiated into a polymer waveguide containing a green quantum dot material, and a polymer waveguide resonant cavity is formed in a photoetching mode; and finally, the two ends of the polymer waveguide are coated to form a green laser, and laser output with the wavelength of 520-540 nm is achieved. The technology depends on a conventional semiconductor laser device process, spin coating and photoetching steps containing green light quantum dot polymers are only added on P-face metal, mass production can be achieved, meanwhile, the laser device cost can be effectively reduced, and green light laser output can be achieved without subsequent optical crystals and frequency doubling crystals.

Description

Technical Field

[0001] The invention relates to a semiconductor-pumped quantum dot green laser and a manufacturing method thereof, belonging to the technical field of lasers. Background Art

[0002] Semiconductor lasers in the visible light band have been widely used in the fields of architecture, laser display, industry and medical equipment due to their high efficiency, small size and high reliability. Among them, semiconductor lasers in the green light band used for indication are widely used in outdoor laser indication, distance measurement marking, laser sensor devices and medical equipment due to their excellent photoelectric conversion rate and human eye sensitivity. However, the current semiconductor laser materials in the green light band are mainly GaN / InGaN compound materials, which have a high band gap and the lowest tunable band gap is still higher than 2.33eV in the positive green light 532nm band, causing the output wavelength of such semiconductor lasers to deviate from 532nm, mainly concentrated between 510nm-520nm, with serious color deviation, which seriously limits their application. In addition, there are technical solutions and systems that use semiconductor lasers to pump crystal materials to generate 1064nm lasers, and then use nonlinear crystals to double the frequency to generate 532nm lasers. However, this system includes semiconductor lasers and crystals, with complex optical paths, high costs, and large volumes. It cannot meet the needs of large-scale production in the industry, which seriously affects the production and use of green semi-lasers and causes high equipment costs.

[0003] There are several solutions to the above problems: First, through the doping and structural research of compound semiconductor materials, the band gap of GaN and InGaN compound materials can be reduced as much as possible, and the wavelength can be as close to 532nm as possible through material doping and laser structural design. However, the physical mechanism has already approached the theoretical limit of the material, which makes it difficult to achieve; doping will greatly reduce the quality of material growth, and the introduction of defects will cause a significant decrease in chip output power and efficiency, which will lose its application value. The second solution is to integrate optical components such as semiconductor pumps, crystals, and nonlinear crystals as much as possible to reduce the size of green lasers, but this solution still belongs to optical system assembly technology, and cannot achieve chip-level mass production and large-scale production, which brings limited cost control. Summary of the invention

[0004] The present invention provides a semiconductor-pumped quantum dot green laser and a method for making the same. On the basis of a conventional blue semiconductor laser, a green quantum dot material is uniformly mixed into an organic liquid material, and the material is covered on the surface of the blue semiconductor laser by photolithography. The surface of the blue laser is provided with a surface grating, and the laser is emitted along the laser surface, enters the polymer waveguide layer on the surface, and excites the mixed green quantum dots in the waveguide layer. Optical coating is performed on both ends of the polymer waveguide layer, and the layer is set as a resonant cavity, and finally the green light output is realized.

[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 limiting layer is partially removed by etching technology to form a shoulder, a ridge waveguide is formed between the two shoulders, an ohmic contact layer is covered above the ridge waveguide, and an insulating layer is covered above and on the side of the shoulder. The insulating layer is provided with 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-side 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 arranged above the ridge waveguide, and the length of the grating is consistent with the length of the ridge waveguide; a P-surface metal layer is covered above the insulating layer, the P-limiting layer and the ohmic contact layer, and a vacant area exists in the P-surface metal layer in the extension direction of the ridge waveguide, the length of the vacant area is less than the length of the ridge waveguide, and the width of the vacant area is less than the width of the ridge waveguide; a quantum dot light-emitting layer is arranged above the grating, and the width of the quantum dot light-emitting layer is consistent with the width of the ridge waveguide;

[0009] The bottom of the substrate is thinned and provided with an N-face metal layer.

[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 2 μm-200 μm, and the chip thickness is 50 μm-200 μm. Preferably, the ridge waveguide width is 20 μm, and the chip thickness is 120 μm.

[0012] Preferably, the upper part of the ridge waveguide is etched to form an equally spaced concave-convex periodic structure to form a grating, and the concave part is obtained by etching the ohmic contact layer and part of the P restriction layer on the upper part of the ridge waveguide, and the etching depth is 10nm-1000nm; the concave-convex structure accounts for 50% in the grating period, that is, the concave-convex structure has the same length.

[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 is the reflection center wavelength. In the present invention, λ c 300-500nm; n neff is the effective refractive index of the grating material, and its value is generally 1.4-3.4 according to different depths; Λ is the period of the grating concave-convex structure, and in the present invention, when the period m is an even number, the grating period is calculated according to the central wavelength. According to the present invention, preferably, Λ is 120-300nm.

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

[0017] Preferably, the quantum dot light-emitting layer is prepared from quantum dots and liquid polymer, and the mass ratio of quantum dots to liquid polymer is 0.1%-5%; the selection of quantum dots is mainly based on the position of the peak of their fluorescence emission spectrum, the emission peak of quantum dots is 520nm-540nm, and the viscosity of the liquid polymer is 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, GaAs in the III-V group material system, CdS, CdSe, ZnSeTe, ZnSeS, ZnS, HgTe in the II-VI group material system, SnTe, PbS, PbSe in the IV-VI group material system;

[0020] In order to ensure that the liquid polymer has the ability to transmit light within the required laser wavelength range, the liquid polymer includes but is not limited to PMMA (polymethyl methacrylate), PSU (polysulfone), PET (polyethylene terephthalate), COC (cyclic olefin copolymer), TPX (poly 4-methylpentene-1 monomer), PS (phosphatidylserine), NAS (N-acryloyloxysuccinimide), and ADC (allyl diglycol carbonate).

[0021] A method for manufacturing the semiconductor-pumped quantum dot green laser comprises the following steps:

[0022] (1) using MOCVD to sequentially grow an N confinement layer, an N waveguide layer, a quantum well active layer, a P waveguide layer, and a P confinement layer on a substrate;

[0023] (2) After photolithography and development, a ridge waveguide and a shoulder are prepared at a specific location using etching technology, and an ohmic contact layer is prepared above the ridge waveguide;

[0024] (3) using PECVD technology to grow silicon dioxide to form an insulating layer, and removing the insulating layer above and on one side of the ridge waveguide by photolithography, etching or stripping, with the distance between the edge of the insulating layer and the edge of the ridge waveguide being less than 5 μm;

[0025] (4) a grating is prepared on the upper part of the ridge waveguide by photolithography and etching, and the concave and convex structures account for 50% of the grating period;

[0026] (5) a P-side metal layer is prepared by evaporation, wherein a vacant region exists in the middle region of the P-side metal layer in the extension direction of the ridge waveguide, the length of the vacant region is less than the length of the ridge waveguide, the width is less than the width of the ridge waveguide, and the width and length of the vacant region account for 50% of the width and length of the ridge waveguide respectively;

[0027] (6) Preparing a quantum dot light-emitting layer: mixing the quantum dots and the liquid polymer uniformly, stirring and ultrasonically treating to form a liquid mixture, and spin-coating the liquid mixture 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 consistent with the width of the ridge waveguide;

[0029] (8) The substrate is thinned, and then an N-side metal layer is prepared by evaporation; after alloy treatment, the laser cavity surface is cleaved, and finally a high-reflection film is plated on the laser cavity surface to form a semiconductor laser; a green light high-reflection film and a partial reflection film are plated on both ends of the polymer waveguide, and finally a semiconductor-pumped quantum dot green light laser is prepared, wherein 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] The quantum dots are placed in a liquid polymer and ultrasonically treated while being stirred to uniformly disperse the quantum dots to form a stable polymer suspension. The laser cavity surface is perpendicular to the plane where the ridge waveguide is located, and the liquid polymer mixed with the quantum dots is dispensed and spin-coated to form a polymer liquid film with uniform thickness of 0.5-10 μm above the laser ridge waveguide, and 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 light curing, or a hot oven with a temperature range of 100°C-450°C is used for heat curing.

[0033] Anything not described or limited in the above technical solution shall be carried out with reference to the prior art.

[0034] The beneficial effects of the present invention are:

[0035] The present invention couples blue light to the waveguide surface through a grating structure for output based on a conventional edge-emitting blue light semiconductor laser. The blue light is irradiated into a polymer waveguide containing green quantum dot material, and a polymer waveguide resonant cavity is formed by photolithography. Finally, a film is formed at both ends of the polymer waveguide to form a green laser and output green laser. This invention effectively makes up for the defect of insufficient wavelength of existing GaN materials, and can achieve laser output with a wavelength of 520-540nm through the selection of quantum dot diameter and material. Moreover, this technology relies on conventional semiconductor laser process, and only adds polymer spin coating and photolithography steps on metal, which can achieve mass production and effectively reduce the cost of lasers at the same time, eliminating the subsequent solid laser system composed of optical crystals and frequency doubling crystals, effectively reducing the overall cost of lasers. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0037] Figure 1 A conventional edge-emitting blue light semiconductor laser without the P-side metal layer and the N-side metal layer in the prior art;

[0038] Figure 2 It is a conventional edge-emitting blue light semiconductor laser in the prior art;

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

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

[0041] Figure 5 This is a schematic diagram of the structure of the semiconductor-pumped quantum dot green laser 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-side metal layer, 13. N-side metal layer, 14. grating, 15. quantum dot light-emitting layer, 16. quantum dots. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of the present invention are clearly and completely described, but not limited to this. Anything not fully described in the present invention shall be based on conventional techniques in the art.

[0044] Example 1

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

[0046] The P limiting layer 6 is partially removed by etching technology 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, and an insulating layer 11 is covered above and on the side of the shoulder 7. The insulating layer 11 is provided with 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 is in contact with the ohmic contact layer, so that current is injected only into the ohmic contact layer above the ridge waveguide;

[0047] A grating 14 is arranged above the ridge waveguide 9, and the length of the grating 14 is consistent with the length of the ridge waveguide 9; a P-face metal layer 12 is covered above the insulating layer 11, the P-limiting layer 6 and the ohmic contact layer 10, and the P-face metal layer 12 has a vacant area in the elongation direction of the ridge waveguide, the length of the vacant area is less than the length of the ridge waveguide, and the width of the vacant area is less than the width of the ridge waveguide, and a quantum dot light-emitting layer 15 is arranged above the grating, and the width of the quantum dot light-emitting layer 15 is consistent with the width of the ridge waveguide 9;

[0048] The bottom of the GaAs substrate 1 is thinned and an N-face metal layer 13 is provided thereon.

[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, except that a grating 14 is formed by etching the upper portion of a ridge waveguide to form an equally spaced concave-convex periodic structure, and the concave portion is obtained by etching the ohmic contact layer 10 and part of the P restriction layer 6 on the upper portion of the ridge waveguide, and the etching depth is 10nm-1000nm; the concave-convex structure accounts for 50% within the grating period, that is, the concave-convex structure has the same length.

[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 is the reflection center wavelength. In the present invention, λ c 300-500nm; n neff is the effective refractive index of the grating material, and its value is generally 1.4-3.4 according to different depths; Λ is the period of the grating concave-convex structure, and in the present invention, when the period m is an even number, the grating period is calculated according to the central wavelength. According to the present invention, preferably, Λ is 120-300nm.

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

[0059] Example 5

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

[0061] The diameter of the quantum dot 16 is 2nm-20nm, and it is InAs in the III-V material system;

[0062] In order 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] The present invention is based on the conventional edge-emitting blue light semiconductor laser. Figure 1 , Figure 2As shown, the blue light is coupled to the waveguide surface through the grating structure for output, the blue light is irradiated into the polymer material waveguide containing the green quantum dot material, and the polymer waveguide resonant cavity is formed by photolithography, and finally the two ends of the polymer waveguide are coated to form a green light laser and output green laser.

[0064] Example 6

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

[0066] (1) An N confinement layer 2, an N waveguide layer 3, a quantum well active layer 4, a P waveguide layer 5 and a P confinement layer 6 are sequentially grown on a GaAs substrate 1 by using a MOCVD method;

[0067] (2) After photolithography and development, a ridge waveguide 9 and a shoulder 7 are prepared at a specific position by etching technology, and an ohmic contact layer 10 is prepared above the ridge waveguide 9;

[0068] (3) using PECVD technology to grow silicon dioxide to form an insulating layer 11, and removing the insulating layer above and on one side of the ridge waveguide by photolithography, etching or stripping, with the distance between the edge of the insulating layer and the edge of the ridge waveguide being less than 5 μm;

[0069] (4) preparing a grating 14 on the upper part of the ridge waveguide by photolithography and etching, wherein the concave and convex structures account for 50% of the period of the grating 14;

[0070] (5) The P-side metal layer 12 is prepared by evaporation, and there is a vacant area in the middle area of ​​the P-side metal layer 12 in the extension direction of the ridge waveguide. The length of the vacant area 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 vacant area account for 50% of the width and length of the ridge waveguide respectively;

[0071] (6) Preparing the quantum dot light-emitting layer 15: uniformly mixing the quantum dots 16 and the liquid polymer, stirring and ultrasonically treating to form a liquid mixture, and spin-coating the liquid mixture 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-side metal layer 13 is prepared by evaporation; after alloy treatment, the laser cavity surface is cleaved, and finally a high-reflection film is plated on the laser cavity surface to form a semiconductor laser; a green light high-reflection film and a partial reflection film are plated on both ends of the polymer waveguide, and finally a semiconductor-pumped quantum dot green light laser is prepared, wherein 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 manufacturing a semiconductor-pumped quantum dot green laser of Example 5 is as described in Example 6, except that the preparation process of the quantum dot light-emitting layer in step (6) is as follows:

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

[0077] Example 8

[0078] A method for manufacturing a semiconductor-pumped quantum dot green laser of Example 5 is as described in Example 7, except that a UV lamp emitting 300nm-450nm is used for photocuring.

[0079] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as 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 limiting layer is partially removed by etching technology to form a shoulder, a ridge waveguide is formed between the two shoulders, the ridge waveguide is covered with an ohmic contact layer, the shoulder and the side are covered with an insulating layer, the insulating layer is provided with an opening at the ridge waveguide, and the edge of the opening is a certain distance away from the edge of the ridge waveguide; A grating is arranged above the ridge waveguide, and the length of the grating is consistent with the length of the ridge waveguide; a P-surface metal layer is covered above the insulating layer, the P-limiting layer and the ohmic contact layer, and a vacant area exists in the P-surface metal layer in the extension direction of the ridge waveguide, the length of the vacant area is less than the length of the ridge waveguide, and the width of the vacant area is less than the width of the ridge waveguide; a quantum dot light-emitting layer is arranged above the grating, and the width of the quantum dot light-emitting layer is consistent with the width of the ridge waveguide; The bottom of the substrate is thinned and provided with an N-face metal layer.

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 width is 2 μm-200 μm, and the chip thickness is 50 μm-200 μm.

4. The semiconductor-pumped quantum dot green laser according to claim 1, characterized in that: The upper part of the ridge waveguide is etched to form an equally spaced concave and convex periodic structure to form a grating. The concave part is obtained by etching the ohmic contact layer and part of the P limit layer on the upper part of the ridge waveguide. The etching depth is 10nm-1000nm; the concave and convex structure accounts for 50% in the grating period.

5. The semiconductor-pumped quantum dot green laser according to claim 1, characterized in that: The quantum dot light-emitting layer is prepared from quantum dots and liquid polymer, the mass ratio of quantum dots to liquid polymer is 0.1%-5%, the emission peak of the quantum dots is 520nm-540nm, and the viscosity of the liquid polymer is 10cp-100cp.

6. The semiconductor-pumped quantum dot green laser according to claim 5, characterized in that: The mass of quantum dots and liquid polymer accounts for 1%.

7. The semiconductor-pumped quantum dot green laser according to claim 6, characterized in that: The diameter of quantum dots is 2nm-20nm, including but not limited to: InAs, InSb, InP, GaAs in III-V material system, CdS, CdSe, ZnSeTe, ZnSeS, ZnS, HgTe in II-VI material system, SnTe, PbS, PbSe in IV-VI material system; The liquid polymer includes, but is not limited to, polymethyl methacrylate, polysulfone, polyethylene terephthalate, cyclic olefin copolymer, poly-4-methylpentene-1 monomer, phosphatidylserine, N-acryloyloxysuccinimide, and allyl diglycol carbonate.

8. A method for manufacturing a semiconductor-pumped quantum dot green laser according to claim 7, characterized in that: The steps include: (1) using MOCVD to sequentially grow an N confinement layer, an N waveguide layer, a quantum well active layer, a P waveguide layer, and a P confinement layer on a substrate; (2) After photolithography and development, a ridge waveguide and a shoulder are prepared by etching technology, and an ohmic contact layer is prepared above the ridge waveguide; (3) using PECVD technology to grow silicon dioxide to form an insulating layer, and removing the insulating layer above and on one side of the ridge waveguide by photolithography, etching or stripping; (4) a grating is prepared on the upper part of the ridge waveguide by photolithography and etching, and the concave and convex structures account for 50% of the grating period; (5) a P-side metal layer is prepared by evaporation, wherein a vacant region exists in the middle region of the P-side metal layer in the extension direction of the ridge waveguide, and the length of the vacant region is smaller than the length of the ridge waveguide, and the width is smaller than the width of the ridge waveguide; (6) Preparing a quantum dot light-emitting layer: mixing the quantum dots and the liquid polymer uniformly, stirring and ultrasonically treating to form a liquid mixture, and spin-coating the liquid mixture 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-side metal layer is prepared by evaporation; after alloy treatment, the laser cavity surface is cleaved, and finally a high-reflection film is plated on the laser cavity surface to form a semiconductor laser; a green light high-reflection film and a partial reflection film are plated on both ends of the polymer waveguide, and finally a semiconductor-pumped quantum dot green light laser is prepared.

9. The method for manufacturing a semiconductor-pumped quantum dot green laser according to claim 8, characterized in that: The preparation process of the quantum dot light-emitting layer in step (6) is as follows: The quantum dots are placed in a liquid polymer and ultrasonically treated while being stirred to uniformly disperse the quantum dots to form a stable polymer suspension. The laser cavity surface is perpendicular to the plane where the ridge waveguide is located, and the liquid polymer mixed with the quantum dots is dispensed and spin-coated to form a polymer liquid film with uniform thickness of 0.5-10 μm above the laser ridge waveguide, and then the polymer liquid film is cured.

10. The method for manufacturing a semiconductor-pumped quantum dot green laser according to claim 9, characterized in that: Use a spotlight that emits ultraviolet or blue light in the wavelength range of 300nm-450nm for light curing, or use a hot oven with a temperature range of 100℃-450℃ for heat curing.

Images