A green laser

Abstract

This invention discloses a green laser, which includes a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer stacked sequentially from bottom to top; the lower waveguide layer and the upper waveguide layer are several InN segregation suppression layers; the several InN segregation suppression layers include GaN and In a Ga 1‑a N, 0.01≤a≤0.4. Using the embodiments of the present invention, InN segregation is reduced, In composition fluctuations are decreased, the gain spectrum of the laser is narrowed, and the peak gain is increased. Simultaneously, the thermal stability of the high-In-composition quantum well in the green laser is improved, thermal degradation is reduced, the quality of the active layer and interface is improved, non-radiative recombination centers are reduced, optical catastrophes are eliminated, and the performance of the green laser is enhanced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor optoelectronics technology, and more particularly to a green laser. Background Technology

[0002] Lasers are widely used in laser displays, laser TVs, laser projectors, communications, medical applications, weaponry, guidance, ranging, spectral analysis, cutting, precision welding, and high-density optical storage. There are many types of lasers, and they can be classified in various ways, mainly including solid-state, gas, liquid, semiconductor, and dye lasers. Compared with other types of lasers, all-solid-state semiconductor lasers have advantages such as small size, high efficiency, light weight, good stability, long lifespan, simple and compact structure, and miniaturization.

[0003] There are significant differences between lasers and nitride semiconductor light-emitting diodes (LEDs): 1) Lasers are generated by stimulated emission of charge carriers, resulting in a narrow spectral width at half maximum (FW / HM) and very high brightness; a single laser can achieve output power in the W range. In contrast, nitride LEDs are generated through spontaneous emission, with output power in the mW range. 2) Lasers operate at current densities of up to kA / cm², more than two orders of magnitude higher than nitride LEDs. This leads to stronger electron leakage, more severe Auger recombination, stronger polarization effects, and more severe electron-hole mismatch, resulting in a more severe drop effect and efficiency degradation. 3) The LED... The spontaneous emission of light from a diode (LED) occurs without external influence, producing incoherent light from a high energy level to a low energy level. In contrast, laser emission is stimulated emission, where the energy of the induced photon must equal the energy difference between the electron and the transition energy levels to produce coherent light. 4) The principles differ: LEDs emit light through radiative recombination when electrons and holes transition to the active layer or pn junction under external voltage. Lasers, however, require specific lasing conditions to be met. Specifically, the active region must have a reversed carrier distribution. Stimulated emission light oscillates within the resonant cavity, and its propagation in the gain medium amplifies the light. Meeting the threshold condition ensures that the gain exceeds the loss, ultimately resulting in laser output. Existing lasers primarily use nitride semiconductor lasers. However, the increased In content in the quantum well leads to poorer peak-tuning gain and thermal stability, resulting in lower performance in nitride semiconductor lasers. Summary of the Invention

[0004] This invention provides a green laser to solve the technical problem of low performance in existing nitride semiconductor lasers due to the increase of In content.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a green laser, comprising a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer stacked sequentially from bottom to top;

[0006] The lower waveguide layer and the upper waveguide layer are several layers of InN segregation suppression layers;

[0007] The plurality of InN segregation suppression layers include: GaN and In a Ga 1-a N, 0.01≤a≤0.4.

[0008] This invention comprises an upper waveguide layer and a lower waveguide layer disposed above and below the active region of a laser, and the upper and lower waveguide layers contain GaN and In. a Ga 1-a N suppresses segregation of In in the active region, reduces In composition fluctuations, narrows the laser's gain spectrum, increases peak gain, and improves the performance of the green laser.

[0009] Furthermore, the plurality of InN segregation suppression layers include: a first InN segregation suppression layer, a second InN segregation suppression layer, and a third InN segregation suppression layer;

[0010] The lower waveguide layer is provided with the first InN segregation suppression layer, the second InN segregation suppression layer and the third InN segregation suppression layer from bottom to top.

[0011] The first InN segregation suppression layer is GaN, and the thickness of the first InN segregation suppression layer is 5-900 nm;

[0012] The second InN segregation suppression layer is In x Ga 1-x N, where the thickness of the second InN segregation suppression layer is 3-600 nm, and x is a constant;

[0013] The third InN segregation suppression layer is In y Ga 1-y N, the thickness of the third InN segregation suppression layer is 1-50nm, and y varies with the quadratic function curve with a quadratic term coefficient greater than 0.

[0014] Furthermore, the plurality of InN segregation suppression layers include: a fourth InN segregation suppression layer;

[0015] The upper waveguide layer is the fourth InN segregation suppression layer;

[0016] The fourth InN segregation suppression layer is In z Ga 1-z N, the thickness of the fourth InN segregation suppression layer is 2-500 nm, and z varies with the parabolic curve.

[0017] Furthermore, the thickness of the fourth InN segregation suppression layer is less than or equal to the thickness of the second InN segregation suppression layer and less than or equal to the thickness of the first InN segregation suppression layer.

[0018] This invention reduces InN segregation and In composition fluctuations by adjusting the thickness of each InN segregation suppression layer, thereby narrowing the laser's gain spectrum, increasing peak gain, and improving the performance of the green laser.

[0019] Furthermore, the active layer is a quantum well structure, comprising: a well layer and a barrier layer; the quantum well period of the active layer is 1-2.

[0020] Wherein, the well layer is In v Ga 1-v N, the thickness of the well layer is 1-4 nm, 0.01≤v≤0.4;

[0021] The barrier layer is GaN, and the thickness of the barrier layer is 2-6 nm.

[0022] Furthermore, the compositional relationship between In of the first InN segregation suppression layer, In of the second InN segregation suppression layer, In of the third InN segregation suppression layer, In of the fourth InN segregation suppression layer, and In of the well layer is as follows:

[0023] 0.01≤y<z min <x<z max <v≤0.4; where z min Let z be the minimum value of z. max This is the maximum value of z.

[0024] This invention also improves the performance of green lasers by adjusting the In composition of InGaN to reduce InN segregation, reduce In composition fluctuations, narrow the gain spectrum of the laser, and increase the peak gain. At the same time, it improves the thermal stability of the high In composition quantum well of the green laser, reduces thermal degradation, improves the quality of the active layer and the interface, reduces nonradiative recombination centers, and eliminates optical catastrophes.

[0025] Furthermore, the first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are all doped with Si;

[0026] Wherein, the Si doping concentration of the fourth InN segregation suppression layer is ≤ the Si doping concentration of the second InN segregation suppression layer is ≤ the Si doping concentration of the first InN segregation suppression layer is ≤ the Si doping concentration of the third InN segregation suppression layer.

[0027] Furthermore, the first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are also doped with H; wherein, the H doping concentration of the fourth InN segregation suppression layer is equal to the H doping concentration of the second InN segregation suppression layer, equal to the H doping concentration of the first InN segregation suppression layer, and equal to the H doping concentration of the third InN segregation suppression layer.

[0028] The first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are further doped with O; wherein, the O doping concentration of the second InN segregation suppression layer = the O doping concentration of the first InN segregation suppression layer = the O doping concentration of the third InN segregation suppression layer ≤ the O doping concentration of the fourth InN segregation suppression layer;

[0029] The first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are further doped with C; wherein, the C doping concentration of the second InN segregation suppression layer = the C doping concentration of the first InN segregation suppression layer = the C doping concentration of the third InN segregation suppression layer ≤ the C doping concentration of the fourth InN segregation suppression layer.

[0030] Further, the lower confining layer includes one or more combinations of AlInGaN, AlInN, AlGaN, InGaN, and GaN, and the thickness of the lower confining layer is 1-900 nm; the upper confining layer includes one or more combinations of AlInGaN, AlInN, and AlGaN, and the thickness of the upper confining layer is 1-900 nm.

[0031] Furthermore, the substrate is a GaN substrate, and the angle between the C-plane and the M-plane of the substrate is 0.1-1°.

[0032] The present invention further improves the beam quality factor and reduces aging light decay by selecting the substrate deflection angle. Attached Figure Description

[0033] Figure 1 A schematic diagram of one embodiment of the green laser provided by the present invention;

[0034] Figure 2 A SIMS secondary ion mass spectrum of an embodiment of the green laser provided by the present invention;

[0035] Figure 3 SIMS secondary ion mass spectrum of another embodiment of the green laser provided by the present invention;

[0036] The reference numerals for the accompanying drawings in the specification are as follows:

[0037] 100. Substrate; 101. Lower confinement layer; 102. Lower waveguide layer; 102a. First InN segregation suppression layer; 102b. Second InN segregation suppression layer; 102c. Third InN segregation suppression layer; 103. Active layer; 104. Upper waveguide layer or fourth InN segregation suppression layer; 105. Upper confinement layer. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Please refer to Figure 1 This is a schematic diagram of an embodiment of the green laser provided by the present invention. The green laser includes a substrate 100, a lower confinement layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, and an upper confinement layer 105 stacked sequentially from bottom to top.

[0040] The lower waveguide layer 102 and the upper waveguide layer 104 are several layers of InN segregation suppression layers;

[0041] The plurality of InN segregation suppression layers include: GaN and In a Ga 1-a N, 0.01≤a≤0.4.

[0042] Generally, an increase in the In composition of the quantum well leads to In composition fluctuations and strain, resulting in a broadened laser gain spectrum and a decrease in peak gain. Increased In composition also worsens thermal stability; high-temperature p-type semiconductor and confinement layer growth cause thermal degradation of the active layer, reducing its quality and interface quality. High defect density within the active layer, a large interfacial gap between InN and GaN, InN phase segregation, thermal degradation, and suboptimal crystal quality further contribute to suboptimal quantum well and interface quality, increasing the number of nonradiative recombination centers or optical catastrophes. This invention provides an upper waveguide layer 104 and a lower waveguide layer 102 above and below the active region of the laser, with the upper waveguide layer 104 and lower waveguide layer 102 comprising GaN and In. a Ga 1-a N suppresses segregation of In in the active region, reduces In composition fluctuations, narrows the laser's gain spectrum, increases peak gain, and improves the performance of the green laser.

[0043] Please refer to Figure 2 and Figure 3These are, respectively, the SIMS secondary ion mass spectra of one embodiment of the green laser provided by the present invention and the SIMS secondary ion mass spectra of another embodiment of the green laser provided by the present invention, wherein the plurality of InN segregation suppression layers include: a first InN segregation suppression layer 102a, a second InN segregation suppression layer 102b and a third InN segregation suppression layer 102c.

[0044] The lower waveguide layer 102 is provided with the first InN segregation suppression layer 102a, the second InN segregation suppression layer 102b and the third InN segregation suppression layer 102c sequentially from bottom to top.

[0045] The first InN segregation suppression layer 102a is GaN, and the thickness of the first InN segregation suppression layer 102a is 5-900 nm.

[0046] The second InN segregation suppression layer 102b is In x Ga 1-x N, where the thickness of the second InN segregation suppression layer 102b is 3-600 nm, and x is a constant;

[0047] The third InN segregation suppression layer 102c is In y Ga 1-y N, the thickness of the third InN segregation suppression layer 102c is 1-50nm, and y varies with the quadratic function curve with a quadratic term coefficient greater than 0.

[0048] In this embodiment, the plurality of InN segregation suppression layers include: a fourth InN segregation suppression layer;

[0049] The upper waveguide layer 104 is the fourth InN segregation suppression layer;

[0050] The fourth InN segregation suppression layer is In z Ga 1-z N, the thickness of the fourth InN segregation suppression layer is 2-500 nm, and z varies with the parabolic curve.

[0051] In each In segregation suppression layer of this embodiment, the InN segregation of the active layer can be controlled by the curve change law satisfied by the In component, thereby achieving segregation suppression.

[0052] In this embodiment, the thickness of the fourth InN segregation suppression layer is less than or equal to the thickness of the second InN segregation suppression layer 102b and less than or equal to the thickness of the first InN segregation suppression layer 102a.

[0053] This invention reduces InN segregation and In composition fluctuations by adjusting the thickness of each InN segregation suppression layer, thereby narrowing the laser's gain spectrum, increasing peak gain, and improving the performance of the green laser.

[0054] In this embodiment, the active layer 103 is a quantum well structure, comprising: a well layer and a barrier layer; wherein, the well layer is In v Ga 1-v N, the thickness of the well layer is 1-4 nm, 0.01≤v≤0.4; the barrier layer is GaN, and the thickness of the barrier layer is 2-6 nm.

[0055] In this embodiment, the active layer 103 is a quantum well structure, and the quantum well period of the active layer 103 is 1-2.

[0056] In this embodiment, when the quantum well period is 2, the well layer includes a first well layer and a second well layer, and the barrier layer includes a first barrier layer, a second barrier layer, and a third barrier layer; the active layer 103 is provided with a first barrier layer, a first well layer, a second barrier layer, a second well layer, and a third barrier layer from bottom to top; each well layer is In v Ga 1-v N, the thickness of the well layer is 1-4 nm, 0.01≤v≤0.4. Each barrier layer is GaN, and the thickness of the barrier layer is 2-6 nm. In this embodiment, the emission wavelength of the quantum well in the active layer 103 is 500-550 nm.

[0057] In this embodiment, the compositional relationship between In of the first InN segregation suppression layer 102a, In of the second InN segregation suppression layer 102b, In of the third InN segregation suppression layer 102c, In of the fourth InN segregation suppression layer, and In of the well layer is as follows:

[0058] 0.01≤y<z min <x<z max <v≤0.4; where z min Let z be the minimum value of z. max This is the maximum value of z.

[0059] This invention also improves the performance of green lasers by adjusting the In composition of InGaN to reduce InN segregation and In composition fluctuations, thereby narrowing the laser's gain spectrum and increasing peak gain. Simultaneously, it enhances the thermal stability of the high-In-composition quantum well in the green laser, reduces thermal degradation, improves the quality of the active layer and interface, reduces non-radiative recombination centers, and eliminates optical catastrophes. Using this embodiment, the aging light attenuation at 1000H is reduced from 20-30% to less than 10%, and the beam quality factor is increased from 1.78 to 1.03.

[0060] Furthermore, the first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are all doped with Si;

[0061] Wherein, the Si doping concentration of the fourth InN segregation suppression layer is ≤ the Si doping concentration of the second InN segregation suppression layer is ≤ the Si doping concentration of the first InN segregation suppression layer is ≤ the Si doping concentration of the third InN segregation suppression layer.

[0062] Furthermore, the first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are also doped with H; wherein, the H doping concentration of the fourth InN segregation suppression layer is equal to the H doping concentration of the second InN segregation suppression layer, equal to the H doping concentration of the first InN segregation suppression layer, and equal to the H doping concentration of the third InN segregation suppression layer.

[0063] The first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are further doped with O; wherein, the O doping concentration of the second InN segregation suppression layer = the O doping concentration of the first InN segregation suppression layer = the O doping concentration of the third InN segregation suppression layer ≤ the O doping concentration of the fourth InN segregation suppression layer;

[0064] The first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are further doped with C; wherein, the C doping concentration of the second InN segregation suppression layer = the C doping concentration of the first InN segregation suppression layer = the C doping concentration of the third InN segregation suppression layer ≤ the C doping concentration of the fourth InN segregation suppression layer.

[0065] In this embodiment, the Si doping concentration in the first InN segregation suppression layer 102a is 10. 18 -10 19 cm -3 The H doping concentration in the first InN segregation suppression layer 102a is 5 × 10⁻⁶. 16 -10 18 cm -3 The C doping concentration in the first InN segregation suppression layer 102a is 5 × 10⁻⁶. 15 -10 17 cm -3 The O doping concentration in the first InN segregation suppression layer 102a is 5 × 10⁻⁶. 15 -10 17 cm -3.

[0066] In this embodiment, the Si doping concentration in the second InN segregation suppression layer 102b is from 10... 18 -5×10 19 cm -3 Gradually decreased to 10 18 -5×10 19 cm -3 The H doping concentration in the second InN segregation suppression layer 102b is 5 × 10⁻⁶. 16 -10 18 cm -3 The C doping concentration in the second InN segregation suppression layer 102b is 5 × 10⁻⁶. 15 -10 17 cm -3 The O doping concentration in the second InN segregation suppression layer 102b is 5 × 10⁻⁶. 15 -10 17 cm -3 .

[0067] In this embodiment, the Si doping concentration in the third InN segregation suppression layer 102c is from 10... 18 -5×10 19 cm -3 Gradually decreased to 5×10 17 -10 19 cm -3 The H doping concentration in the third InN segregation suppression layer 102c is 5 × 10⁻⁶. 16 -10 18 cm -3 The C doping concentration in the third InN segregation suppression layer 102c is 5 × 10⁻⁶. 15 -10 17 cm -3 The O doping concentration in the third InN segregation suppression layer 102c is 5 × 10⁻⁶. 15 -10 17 cm -3 .

[0068] In this embodiment, the Si doping concentration in the fourth InN segregation suppression layer is from 10... 14 -10 16 cm -3 The H doping concentration in the fourth InN segregation suppression layer is 5 × 10⁻⁶. 16 -10 18 cm -3 The C doping concentration in the fourth InN segregation suppression layer is 5 × 10⁻⁶. 15 -10 17 cm-3 The O doping concentration in the fourth InN segregation suppression layer is 5 × 10⁻⁶. 15 -10 17 cm -3 .

[0069] This invention further improves the beam quality factor and reduces aging decay of green lasers by setting and combining the concentrations of H, C, and O in each InN segregation suppression layer.

[0070] In this embodiment, the lower confinement layer 101 includes one or more combinations of AlInGaN, AlInN, AlGaN, InGaN, and GaN, and the thickness of the lower confinement layer 101 is 1-900 nm.

[0071] In this embodiment, the upper confinement layer 105 includes one or more combinations of AlInGaN, AlInN, and AlGaN, and the thickness of the upper confinement layer 105 is 1-900 nm.

[0072] In this embodiment, the substrate 100 is a GaN substrate, and the angle of deviation of the substrate 100 from the C-plane to the M-plane is 0.1-1°.

[0073] The present invention further improves the beam quality factor and reduces aging light decay by selecting the substrate deflection angle.

[0074] Using the embodiments of the present invention, the beam quality of the green laser is improved from 1.78 to 1.03, an improvement of approximately 73%; the focused spot resolution is improved from greater than 200 nm to less than 50 nm, as shown in the table below:

[0075]

[0076]

[0077] Traditional lasers are nitride semiconductor lasers that do not suppress InN segregation near the quantum well. In contrast, this invention modulates the thickness of the InN segregation control layer and the In composition of InGaN to reduce InN segregation and In composition fluctuations, thereby narrowing the laser's gain spectrum and increasing peak gain. At the same time, it improves the thermal stability of the high-In-composition quantum well in the green laser, reduces thermal degradation, improves the quality of the active layer and interface, reduces non-radiative recombination centers, eliminates optical catastrophes, and improves the performance of the green laser.

[0078] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A green laser, characterized in that, It includes a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer stacked sequentially from bottom to top; The lower waveguide layer and the upper waveguide layer are several layers of InN segregation suppression layers; The plurality of InN segregation suppression layers include: GaN and In a Ga 1-a N, 0.01≤a≤0.4; The active layer is a quantum well structure, comprising: a well layer and a barrier layer; the quantum well period of the active layer is 1-2. Wherein, the well layer is In v Ga 1-v N, the thickness of the well layer is 1-4 nm, 0.01≤v≤0.4; The barrier layer is GaN, and the thickness of the barrier layer is 2-6 nm. The plurality of InN segregation suppression layers include: a first InN segregation suppression layer, a second InN segregation suppression layer, a third InN segregation suppression layer, and a fourth InN segregation suppression layer; The compositional relationship between In of the first InN segregation suppression layer, In of the second InN segregation suppression layer, In of the third InN segregation suppression layer, In of the fourth InN segregation suppression layer, and In of the well layer is as follows: 0.01≤y<z min <x<z max <v≤0.4; where z min Let z be the minimum value of z. max The maximum value of z; The lower waveguide layer is provided with the first InN segregation suppression layer, the second InN segregation suppression layer and the third InN segregation suppression layer from bottom to top. The first InN segregation suppression layer is GaN, and the thickness of the first InN segregation suppression layer is 5-900 nm; The second InN segregation suppression layer is InxGa1-xN, and the thickness of the second InN segregation suppression layer is 3-600 nm, where x is a constant; The third InN segregation suppression layer is InyGa1-yN, and the thickness of the third InN segregation suppression layer is 1-50nm. y varies with the quadratic function curve where the coefficient of the quadratic term is greater than 0. The upper waveguide layer is the fourth InN segregation suppression layer; The fourth InN segregation suppression layer is InzGa1-zN, and the thickness of the fourth InN segregation suppression layer is 2-500 nm, with z varying with a parabolic curve.

2. The green laser as described in claim 1, characterized in that, The thickness of the fourth InN segregation suppression layer is less than or equal to the thickness of the second InN segregation suppression layer and less than or equal to the thickness of the first InN segregation suppression layer.

3. The green laser as described in claim 2, characterized in that, The first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are all doped with Si; Wherein, the Si doping concentration of the fourth InN segregation suppression layer is ≤ the Si doping concentration of the second InN segregation suppression layer is ≤ the Si doping concentration of the first InN segregation suppression layer is ≤ the Si doping concentration of the third InN segregation suppression layer.

4. The green laser as described in claim 2, characterized in that, The first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are further doped with H; wherein, the H doping concentration of the fourth InN segregation suppression layer is equal to the H doping concentration of the second InN segregation suppression layer, the H doping concentration of the first InN segregation suppression layer, and the H doping concentration of the third InN segregation suppression layer. The first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are further doped with O; wherein, the O doping concentration of the second InN segregation suppression layer = the O doping concentration of the first InN segregation suppression layer = the O doping concentration of the third InN segregation suppression layer ≤ the O doping concentration of the fourth InN segregation suppression layer; The first InN segregation suppression layer, the second InN segregation suppression layer, the third InN segregation suppression layer, and the fourth InN segregation suppression layer are further doped with C; wherein, the C doping concentration of the second InN segregation suppression layer = the C doping concentration of the first InN segregation suppression layer = the C doping concentration of the third InN segregation suppression layer ≤ the C doping concentration of the fourth InN segregation suppression layer.

5. The green laser as described in any one of claims 1-2, characterized in that, The lower confinement layer comprises one or more combinations of AlInGaN, AlInN, AlGaN, InGaN, and GaN, and the thickness of the lower confinement layer is 1-900 nm; the upper confinement layer comprises one or more combinations of AlInGaN, AlInN, and AlGaN, and the thickness of the upper confinement layer is 1-900 nm.

6. The green laser as described in any one of claims 1-2, characterized in that, The substrate is a GaN substrate, and the angle between the C-plane and the M-plane of the substrate is 0.1-1°.

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