Semiconductor laser

Abstract

A semiconductor laser. The semiconductor laser sequentially comprises, from bottom to top, 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), wherein the lower confinement layer (101) is composed of at least one material of AlInGaN, AlInN, AlGaN, InN, AlN, InGaN, and GaN, the thickness of the lower confinement layer (101) is x, and x is greater than or equal to 10 angstroms and less than or equal to 90,000 angstroms; and the lower confinement layer (101) comprises a first lower confinement layer (101a), a second lower confinement layer (101b), and a third lower confinement layer (101c). The lower confinement layer (101) is used to form an electron storage structure and a stress regulation structure, thereby regulating carrier distribution and stress distribution in the active layer (103), reducing threshold current of the laser, and improving the slope efficiency. Moreover, heat generated by non-radiative recombination loss and free carrier absorption loss is reduced, heat accumulation in the active layer (103) is reduced, thermal conductivity and heat dissipation performance are improved, aging and light attenuation of the laser are alleviated, and focal spot resolution of the laser is improved.

Description

A semiconductor laser

[0001] Cross-references

[0002] This application claims priority to Chinese Patent Application No. 202311387383.8 filed on October 25, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This specification relates to the technical field of semiconductor optoelectronic devices, and in particular to a semiconductor laser. Background Art

[0004] Lasers are widely used in laser displays, laser televisions, laser projectors, communications, medical treatment, weaponry, guidance, atomic clocks, rangefinders, spectral analysis, cutting, submarine communications, precision welding, quantum sensors, and high-density optical storage. There are many types of lasers, classified in various ways, including solid-state, gas, liquid, semiconductor, and dye lasers. Compared with other types of lasers, all-solid-state semiconductor lasers offer advantages such as excellent monochromaticity, good directionality, small size, high brightness, high efficiency, light weight, excellent stability, long life, simple and compact structure, and miniaturization.

[0005] There are significant differences between lasers and nitride semiconductor light-emitting diodes. The main differences include: 1) Lasers are generated by stimulated emission of carriers, with a small spectral half-width and high brightness. The output power of a single laser can be in the W level, while nitride semiconductor light-emitting diodes emit spontaneous radiation, and the output power of a single light-emitting diode is in the mW level; 2) The operating current density of the laser is up to KA / cm 2, which is more than 2 orders of magnitude higher than that of nitride light-emitting diodes, resulting in stronger electron leakage, more serious Auger recombination, stronger polarization effect, more serious electron-hole mismatch, and more serious efficiency attenuation Droop effect; 3) Nitride semiconductor light-emitting diodes spontaneously radiate incoherent light from high energy level to low energy level without external influence, while lasers radiate stimulated transitions. The energy of induced photons should be equal to the difference in energy levels of electron transitions, generating completely coherent light of photons and induced photons; 4) Different principles: Nitride semiconductor light-emitting diodes generate radiative recombination and luminescence under the action of external voltage when electron holes transition to the active layer or pn junction, while lasers require lasing conditions to be met before they can be lased. The carrier inversion distribution in the active region must be met. The stimulated radiation light oscillates back and forth in the resonant cavity, and the propagation in the gain medium amplifies the light. The threshold condition is met so that the gain is greater than the loss, and finally the laser is output. Nitride semiconductor lasers have the following problems: When the laser uses a large current, the current density is high, which generates a lot of heat. In addition, the device has poor heat dissipation and poor temperature characteristics, which will aggravate the thermal mismatch between the semiconductor epitaxial layers, leading to problems such as increased threshold current, decreased output optical power and slope efficiency. Non-radiative recombination losses and free carrier absorption in the active region of the laser chip generate a large amount of heat. At the same time, the resistance of the epitaxial and chip materials will generate Joule heat loss and carrier absorption loss under current injection. In addition, the chip material has low thermal conductivity and poor heat dissipation performance, which leads to increased temperature in the active layer, red shift of the lasing wavelength, decreased quantum efficiency, reduced power, increased threshold current, shortened lifespan and poor reliability.

[0006] The internal optical absorption loss of the laser includes impurity absorption loss, carrier absorption loss, waveguide structure sidewall scattering loss and quantum well absorption loss; the optical waveguide impurity absorption loss is high, the inherent carbon impurities in the p-type semiconductor will compensate the acceptor and destroy the p-type, the p-type doping has a low ionization rate (below 10%), and a large amount of unionized Mg acceptor impurities (more than 90%) will produce a self-compensation effect and cause the internal optical loss to increase, resulting in a decrease in the laser slope efficiency and an increase in the threshold current; and the refractive index dispersion of the laser, the high concentration of carrier concentration fluctuations affect the refractive index of the active layer, and the confinement factor decreases with increasing wavelength, resulting in a decrease in the mode gain of the laser.

[0007] The fewer the number of laser modes, the more favorable it is for stimulated emission, the more favorable it is for improving the degeneracy of photons, and the more favorable it is for stimulated emission to exceed spontaneous emission. The number of laser modes can be reduced by using a Fabry-Perot optical resonator. The types of laser light waves can be divided into transverse modes and longitudinal modes. A standing wave along the axial direction of the cavity is called a longitudinal mode. The transverse mode is a transverse mode in which the light field is unchanged in the transverse direction when the light field is distributed transversely to the cavity, the light is reflected back and forth between the two mirrors, and the equal phase plane of the light wave is equal to the curvature radius of the mirror. The transverse mode intensity distribution in the cross section perpendicular to the optical axis is determined by the waveguide structure of the semiconductor laser. If the transverse mode is complex and unstable, the coherence of the output light is poor. The longitudinal mode is a standing wave distribution in the propagation direction of the resonant cavity, many longitudinal modes are simultaneously emitted or there are inter-mode changes, then high temporal coherence cannot be obtained, and the far-field image FFP quality is poor.

[0008] Therefore, it is hoped to provide a semiconductor laser that can ensure the coherence of the transverse mode, reduce the number of longitudinal modes and the inter-mode variation, and improve the longitudinal mode temporal coherence and far-field FFP image quality.

[0009] Summary of the Invention

[0010] In order to make up for the deficiencies of the prior art, this specification proposes a semiconductor laser.

[0011] The technical solutions adopted by this manual to solve the technical problems are:

[0012] One or more embodiments of this specification provide a semiconductor laser. The semiconductor laser includes, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer. The lower confinement layer is composed of at least one material selected from the group consisting of AlInGaN, AlInN, AlGaN, InN, AlN, InGaN, and GaN. The thickness of the lower confinement layer is x, where 10 angstroms ≤ x ≤ 90,000 angstroms. The lower confinement layer includes a first lower confinement layer, a second lower confinement layer, and a third lower confinement layer.

[0013] In some embodiments, the thermal conductivities of the first lower confinement layer, the second lower confinement layer, and the third lower confinement layer are a, b, and c, respectively, wherein 2.5(10 -6 / K)≤b≤a≤c≤5.5(10 -6 / K); the electron effective masses of the first lower confinement layer, the second lower confinement layer and the third lower confinement layer are d, e and f, respectively, wherein 200me≤e≤f≤d≤400me; the Philips ionization degrees of the first lower confinement layer, the second lower confinement layer and the third lower confinement layer are g, h and i, respectively, wherein 3≤i≤g≤h≤4.

[0014] In some embodiments, the ratio of In element content / Mg element content and the ratio of Si element content / Mg element content of the second lower limiting layer have a "∩" type distribution, and the ratio of Al element content / Mg element content of the second lower limiting layer has a "∪" type distribution.

[0015] In some embodiments, the thermal conductivity distribution and electron effective mass distribution of the second lower confinement layer have a “∪” type distribution, and the Philips ionization degree distribution and electron affinity distribution of the second lower confinement layer have a “∩” type distribution.

[0016] In some embodiments, the thermal conductivity distribution of the second lower confining layer corresponds to a curve distribution of a first function, where the first function is y=ix 2 +jx+k(i>0), the electron effective mass distribution of the second lower confinement layer corresponds to the curve distribution of the second function, and the second function is y=mx 2 +nx+o(m>0), the Philips ionization degree distribution of the second lower confinement layer corresponds to the curve distribution of the third function, and the third function is y=px 2 +qx+r(p<0), the electron affinity distribution of the second lower confinement layer corresponds to the curve distribution of the fourth function, and the fourth function is y=sx 2 +tx+u(s<0), where s<p<0<i≤m, j, k, n, o, q, r, t and u are arbitrary preset values.

[0017] In some embodiments, the active layer is a periodic structure consisting of a well layer and a barrier layer, and the periodic structure includes 1 to 3 groups of the well layer and the barrier layer; the well layer and the barrier layer are respectively GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, I The invention is composed of at least one material selected from nAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN and diamond, the thickness of the well layer is 10 angstroms to 120 angstroms; the thickness of the barrier layer is 10 angstroms to 200 angstroms; the refractive index coefficient of the well layer is greater than or equal to the refractive index coefficient of the barrier layer; the dielectric constant of the well layer is greater than or equal to the dielectric constant of the barrier layer; and the piezoelectric polarization coefficient of the well layer is greater than or equal to the piezoelectric polarization coefficient of the barrier layer.

[0018] In some embodiments, the active layer includes a first active layer and a second active layer; the refractive index coefficients of the well layer and the barrier layer of the first active layer are A and B, respectively, and the refractive index coefficients of the well layer and the barrier layer of the second active layer are C and D, respectively, wherein 2.0≤B≤D≤A≤C≤3.0; the dielectric constants of the well layer and the barrier layer of the first active layer are E and F, respectively, and the dielectric constants of the well layer and the barrier layer of the second active layer are G and H, respectively, wherein 8≤G≤E≤H≤F≤12; the piezoelectric polarization coefficients of the well layer and the barrier layer of the first active layer are I and J, respectively, and the piezoelectric polarization coefficients of the well layer and the barrier layer of the second active layer are K and L, respectively, wherein 0.7≤J≤L≤I≤K≤1.0.

[0019] In some embodiments, the refractive index coefficient, dielectric constant and piezoelectric polarization coefficient of the first active layer are all W-shaped distributions, and the refractive index coefficient, dielectric constant and piezoelectric polarization coefficient of the second active layer are all M-shaped distributions.

[0020] In some embodiments, the upper waveguide layer is an upper waveguide layer that suppresses light absorption loss; the upper waveguide layer is composed of at least one material selected from the group consisting of GaN, InGaN, InN, AlInN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond, and the thickness of the upper waveguide layer is 200 angstroms to 8000 angstroms; the conduction band effective state density distribution, electron affinity distribution, and breakdown field strength distribution of the upper waveguide layer are all arc-shaped; the conduction band effective state density distribution corresponds to the curve distribution of a fifth function, and the fifth function is y=log v x(0<v<1); the electron affinity distribution corresponds to the curve distribution of the sixth function, and the sixth function is y=log w x(w>1); The breakdown field strength distribution corresponds to the curve distribution of the seventh function, and the seventh function is y=log z x(z>1); wherein, 0<v<1 <w<z<500.

[0021] In some embodiments, the lower waveguide layer and the upper confinement layer are respectively composed of at least one material selected from the group consisting of GaN, InGaN, InN, AlInN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond. The thickness of the lower waveguide layer is 10 angstroms to 50,000 angstroms; the thickness of the upper confinement layer is 10 angstroms to 80,000 angstroms; and the substrate comprises sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, Cu, W, Mo, TiW, GaSb, InSb, InP, a sapphire / SiO2 composite substrate, a sapphire / AlN composite substrate, a sapphire / SiN x , any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, MgO, spinel, ZrB2, diamond, LiAlO2 and LiGaO2 composite substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0023] The present specification is further described below with reference to the accompanying drawings and implementation examples.

[0024] FIG1 is a schematic structural diagram of a semiconductor laser according to some embodiments of this specification;

[0025] FIG2 is a SIMS secondary ion mass spectrum of a semiconductor laser according to some embodiments of the present specification;

[0026] FIG3 is another SIMS secondary ion mass spectrum of a semiconductor laser according to some embodiments of the present specification;

[0027] FIG4 is a TEM image of a lower confinement layer of a semiconductor laser obtained when the size of the TEM image is 200 nm according to some embodiments of this specification;

[0028] FIG5 is a TEM image of a lower confinement layer and a lower waveguide layer of a semiconductor laser obtained when the size of the TEM is 500 nm according to some embodiments of this specification;

[0029] FIG6 is a TEM image of an active layer of a semiconductor laser obtained when the size of the TEM image is 20 nm according to some embodiments of this specification;

[0030] FIG7 is a TEM image of an upper waveguide layer and a lower waveguide layer of a semiconductor laser obtained when the size of the TEM is 200 nm according to some embodiments of this specification;

[0031] FIG8 is a TEM image of an upper confinement layer of a semiconductor laser obtained when the TEM size is 100 nm according to some embodiments of the present specification.

[0032] Reference numerals: 100: substrate; 101: lower confinement layer; 101a: first lower confinement layer; 101b: second lower confinement layer; 101c: third lower confinement layer; 102: lower waveguide layer; 103: active layer; 104: upper waveguide layer; 105: upper confinement layer. DETAILED DESCRIPTION

[0033] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings used in describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art will be able to apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or indicated otherwise, the same reference numerals in the figures represent the same structure or operation.

[0034] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. The device may also include other elements.

[0035] In order to make the technical means, creative features, objectives and effects achieved in this specification easy to understand, this specification is further explained below in conjunction with specific implementation methods.

[0036] Figure 1 is a schematic diagram of the structure of a semiconductor laser according to some embodiments of the present specification. Figure 2 is a SIMS secondary ion mass spectrum of a semiconductor laser according to some embodiments of the present specification. Figure 3 is another SIMS secondary ion mass spectrum of a semiconductor laser according to some embodiments of the present specification.

[0037] The horizontal axis in Figures 2 and 3 represents the depth of each element in the semiconductor laser, in μm. The vertical axis on the left side of Figures 2 and 3 represents the concentration of each element in each layer of the semiconductor laser, in atoms / cm 3 The right vertical axis in Figures 2 and 3 represents the ion intensity of each element in each layer of the semiconductor laser, with the unit being au.

[0038] As shown in FIG. 1 to FIG. 3 , a semiconductor laser provided in an embodiment of this specification includes, from bottom to top, 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 .

[0039] The lower confinement layer 101 can be used to regulate the carrier distribution and stress distribution of the active layer 103 , and reduce heat accumulation in the active layer 103 .

[0040] In some embodiments, the lower confinement layer 101 is composed of at least one of AlInGaN, AlInN, AlGaN, InN, AlN, InGaN, and GaN. For example, the lower confinement layer 101 is composed of AlInGaN and AlInN materials.

[0041] In some embodiments, the thickness of the lower confinement layer 101 is x, where 10 angstroms ≤ x ≤ 90,000 angstroms. For example, the thickness x of the lower confinement layer is 10 angstroms. For another example, the thickness x of the lower confinement layer is 44,995 angstroms. For another example, the thickness x of the lower confinement layer is 90,000 angstroms.

[0042] In some embodiments of the present specification, by setting the lower confinement layer to a three-layer structure, setting the thickness to 10 angstroms ≤ x ≤ 90000 angstroms and setting the material of the lower confinement layer (101) to be composed of at least one material of AlInGaN, AlInN, AlGaN, InN, AlN, InGaN and GaN, the coherence of the transverse mode is ensured, and the number of longitudinal modes and the inter-mode variation are reduced, thereby improving the longitudinal mode temporal coherence and the far-field FFP image quality.

[0043] Figure 4 is a TEM image of the lower confinement layer of a semiconductor laser obtained when the TEM size is 200 nm according to some embodiments of this specification. Figure 5 is a TEM image of the lower confinement layer and lower waveguide layer of a semiconductor laser obtained when the TEM size is 500 nm according to some embodiments of this specification.

[0044] In some embodiments, as shown in FIG. 4 , the lower confinement layer 101 includes a first lower confinement layer 101 a , a second lower confinement layer 101 b , and a third lower confinement layer 101 c .

[0045] The first lower confinement layer 101 a refers to a lower confinement layer adjacent to the substrate 100 .

[0046] The second lower confinement layer 101 b refers to a lower confinement layer located between the first lower confinement layer 101 a and the third lower confinement layer 101 c .

[0047] As shown in FIG. 5 , the third lower confinement layer 101 c refers to a lower confinement layer adjacent to the lower waveguide layer 102 .

[0048] In some embodiments, the thermal conductivities of the first lower confinement layer 101a, the second lower confinement layer 101b, and the third lower confinement layer 101c are a, b, and c, respectively, wherein 2.5(10 -6 / K)≤b≤a≤c≤5.5(10 -6 For example, the thermal conductivity of the first lower confinement layer 101a, the second lower confinement layer 101b, and the third lower confinement layer 101c are respectively a=3.5(10 -6 / K), b=2.5(10 -6 / K) and c=5.5(10 -6 / K).

[0049] Thermal conductivity can be used to characterize the thermal conductivity of the lower confinement layer (eg, the first lower confinement layer 101a, the second confinement layer 101b, and the third confinement layer 101c).

[0050] In some embodiments, the electron effective masses of the first lower confinement layer 101a, the second lower confinement layer 101b, and the third lower confinement layer 101c are d, e, and f, respectively, where 200 me ≤ e ≤ f ≤ d ≤ 400 me. For example, the electron effective masses of the first lower confinement layer 101a, the second lower confinement layer 101b, and the third lower confinement layer 101c are d = 400 me, e = 200 me, and f = 300 me, respectively.

[0051] The electron effective mass can be used to characterize the force of the internal potential field of the lower confinement layer (eg, the first lower confinement layer 101a, the second confinement layer 101b, and the third confinement layer 101c).

[0052] In some embodiments, the Philips ionizations of first lower confinement layer 101a, second lower confinement layer 101b, and third lower confinement layer 101c are g, h, and i, respectively, where 3≤i≤g≤h≤4. For example, the Philips ionizations of first lower confinement layer 101a, second lower confinement layer 101b, and third lower confinement layer 101c are g=3.5, h=4, and i=3, respectively.

[0053] The Phillips ionization degree can be used to indicate the ratio of ionizable particles to total particles in the lower confinement layer (eg, the first lower confinement layer 101a, the second confinement layer 101b, and the third confinement layer 101c).

[0054] In some embodiments of the present specification, the thermal conductivities of the first lower confinement layer 101a, the second lower confinement layer 101b, and the third lower confinement layer 101c are set to a, b, and c, respectively, wherein 2.5(10 -6 / K)≤b≤a≤c≤5.5(10 -6 / K), which can effectively reduce the heat accumulation of the active layer; by setting the electron effective masses of the first lower confinement layer 101a, the second lower confinement layer 101b and the third lower confinement layer 101c to d, e and f, respectively, where 200me≤e≤f≤d≤400me, the stress distribution of the active layer is optimized; by setting the Philips ionization degrees of the first lower confinement layer 101a, the second lower confinement layer 101b and the third lower confinement layer 101c to g, h and i, respectively, where 3≤i≤g≤h≤4, the carrier distribution of the active layer is optimized, thereby further ensuring the coherence of the transverse mode, reducing the number of longitudinal modes and the inter-mode variation, and improving the longitudinal mode temporal coherence and the far-field FFP image quality.

[0055] In some embodiments, the ratio of In element content / Mg element content and the ratio of Si element content / Mg element content of the second lower confinement layer 101b have a "∩" type distribution, and the ratio of Al element content / Mg element content of the second lower confinement layer 101b has a "∪" type distribution.

[0056] The In content / Mg content ratio refers to the ratio of the mass of In contained in each of the multiple regions of the second lower confinement layer to the mass of Mg contained in each region. The second lower confinement layer can be divided into multiple regions in various ways. For example, the second lower confinement layer can be divided into n regions of equal proportion, where n ≥ 2 and n is a positive integer.

[0057] The ratio of Si element content to Mg element content refers to the ratio of the mass of Si element contained in each of the plurality of regions divided by the second lower confinement layer to the mass of Mg element contained in each region.

[0058] The “∩”-shaped distribution of the ratio of In element content / Mg element content means that the distribution of the ratio of In element content / Mg element content in each of the multiple regions divided by the second lower confinement layer is “∩”-shaped.

[0059] The "∩"-shaped distribution of the Si element content / Mg element content ratio and the "∪"-shaped distribution of the Al element content / Mg element content ratio have similar meanings to the "∩"-shaped distribution of the In element content / Mg element content ratio. Please refer to the above description for details.

[0060] In some embodiments of the present disclosure, by configuring the ratios of the In element content to the Mg element content and the Si element content to the Mg element content in the second lower confinement layer to have a ∩-shaped distribution, and configuring the ratio of the Al element content to the Mg element content to have a ∪-shaped distribution, the thermal expansion coefficient of the second lower confinement layer has an inverted ∪-shaped distribution, the elastic modulus of the second lower confinement layer has a ∪-shaped distribution, and the lattice constant of the second lower confinement layer has a positive ∩-shaped distribution. This creates an electron storage structure and a stress regulation structure, modulating the carrier and stress distribution in the active layer, lowering the threshold current of the laser and improving the slope efficiency. Furthermore, the structure suppresses the Auger non-radiative recombination efficiency, reduces the heat generated by non-radiative recombination loss and free-carrier absorption loss, reduces heat accumulation in the active layer, improves thermal conductivity and heat dissipation, and improves the aging optical decay and focus spot resolution of the laser. The aging optical decay over 1000 hours is reduced from 22% to less than 4%, and the focus spot resolution is reduced from greater than 200nm to less than 40nm.

[0061] In some embodiments, the thermal conductivity distribution and electron effective mass distribution of the second lower confinement layer 101b have a “∪” type distribution, and the Philips ionization degree distribution and electron affinity distribution of the second lower confinement layer 101b have a “∩” type distribution.

[0062] The thermal conductivity distribution refers to the distribution of the thermal conductivity of each region among the multiple regions divided by the second lower confinement layer.

[0063] The electron effective mass distribution refers to the distribution of the potential field force within each region among the multiple regions divided by the second lower confinement layer.

[0064] The Philips ionization degree distribution refers to the distribution of the Philips ionization degree within each of the multiple regions divided by the second lower confinement layer.

[0065] The electron affinity distribution refers to the distribution of the ability of each atomic center to acquire electrons within the second lower confinement layer.

[0066] In some embodiments of the present specification, by setting the thermal conductivity distribution and the electron effective mass distribution of the second lower confinement layer to a "∪"-type distribution, and setting the Philips ionization degree distribution and the electron affinity distribution to a "∩"-type distribution, the thermal expansion coefficient of the second lower confinement layer has an inverted "∪"-type distribution, the elastic modulus of the second lower confinement layer has a "∪"-type distribution, and the lattice constant of the second lower confinement layer has a positive "∩"-type distribution, thereby forming an electron storage structure and a stress regulation structure, regulating the carrier distribution and stress distribution of the active layer, reducing the threshold current of the laser and improving the slope efficiency.

[0067] In some embodiments, the thermal conductivity distribution of the second lower confinement layer 101b corresponds to the curve distribution of the first function, and the first function is y=ix 2 +jx+k(i>0).

[0068] In some embodiments, the electron effective mass distribution of the second lower confinement layer 101b corresponds to the curve distribution of the second function, and the second function is y=mx 2 +nx+o(m>0).

[0069] In some embodiments, the Philips ionization degree distribution of the second lower confinement layer 101b corresponds to a curve distribution of a third function, where the third function is y=px 2 +qx+r(p<0).

[0070] In some embodiments, the electron affinity distribution of the second lower confinement layer 101b corresponds to the curve distribution of the fourth function, and the fourth function is y=sx 2 +tx+u(s<0), where s<p<0<i≤m, j, k, n, o, q, r, t, and u are any preset values. j, k, n, o, q, r, t, and u can be preset by those skilled in the art based on experience.

[0071] In some embodiments of the present specification, by setting the thermal conductivity distribution, electron effective mass distribution, Philips ionization distribution and electron affinity distribution of the second lower confinement layer to specific function curves, the thermal conductivity distribution and electron effective mass distribution of the second lower confinement layer are closer to a "∪"-type distribution, and the Philips ionization distribution and electron affinity distribution are closer to a "∩"-type distribution, so that the thermal expansion coefficient of the second lower confinement layer has an inverted "∪"-type distribution, the elastic coefficient of the second lower confinement layer has a "∪"-type distribution, and the lattice constant of the second lower confinement layer has a positive "∩"-type distribution, forming an electron storage structure and a stress regulation structure, regulating the carrier distribution and stress distribution of the active layer, reducing the threshold current of the laser and improving the slope efficiency.

[0072] FIG6 is a TEM image of an active layer of a semiconductor laser obtained when the TEM size is 20 nm according to some embodiments of this specification.

[0073] The active layer refers to the thin layer used to generate photons and perform light amplification.

[0074] 6 , the active layer 103 is a periodic structure composed of well layers and barrier layers. In some embodiments, the periodic structure includes 1 to 3 groups of well layers and barrier layers.

[0075] The well layer refers to the region in a semiconductor laser where the electron energy is higher than the valence band but lower than the conduction band.

[0076] The barrier layer refers to the blocking layer formed by the diffusion of electrons and holes in the PN junction of a semiconductor laser.

[0077] In some embodiments, the well layer and the barrier layer are respectively composed of at least one material selected from the group consisting of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN and diamond.

[0078] In some embodiments, the thickness of the well layer is 10 angstroms to 120 angstroms, and the thickness of the barrier layer is 10 angstroms to 200 angstroms.

[0079] In some embodiments, the refractive index of the well layer is greater than or equal to the refractive index of the barrier layer.

[0080] The refractive index refers to the ratio of the propagation speed of light in a vacuum to the propagation speed of light in a medium (eg, a well layer or a barrier layer).

[0081] In some embodiments, the dielectric constant of the well layer is greater than or equal to the dielectric constant of the barrier layer.

[0082] The dielectric constant refers to the ratio of the electric field strength within a dielectric (eg, a well layer or a barrier layer) to the electric field strength outside the dielectric.

[0083] In some embodiments, the piezoelectric polarization coefficient of the well layer is greater than or equal to the piezoelectric polarization coefficient of the barrier layer.

[0084] The piezoelectric polarization coefficient can be used to characterize the degree of polarization generated in the well layer or barrier layer under the action of an external electric field.

[0085] In some embodiments of the present specification, the active layer is a periodic structure composed of a well layer and a barrier layer, the refractive index coefficient of the well layer in the active layer is greater than or equal to the refractive index coefficient of the barrier layer; the dielectric constant of the well layer in the active layer is greater than or equal to the dielectric constant of the barrier layer; the piezoelectric polarization coefficient of the well layer in the active layer is greater than or equal to the piezoelectric polarization coefficient of the barrier layer, thereby improving the photon degeneracy of the active layer and the symmetry of the conduction band and the heavy hole band of the semiconductor laser. Under the same injection current, the quasi-Fermi levels of the conduction band and the heavy hole band will enter their respective energy bands with equal probability, reducing the threshold current density required to achieve particle number inversion, making the stimulated radiation of the semiconductor laser greater than the spontaneous radiation, improving the coherence, confinement factor and slope efficiency of the transverse mode, and reducing the number of longitudinal modes and inter-mode variation, thereby improving the longitudinal mode temporal coherence and far-field FFP image quality, beam quality factor and focused spot resolution.

[0086] In some embodiments, the active layer 103 includes a first active layer and a second active layer.

[0087] The first active layer refers to a thin layer separated from the active layer. The first active layer may include a well layer and a barrier layer of the first active layer.

[0088] The second active layer refers to a thin layer separated from the first active layer and may include a well layer and a barrier layer of the second active layer.

[0089] In some embodiments, the refractive index coefficients of the well layer and the barrier layer of the first active layer are A and B, respectively, and the refractive index coefficients of the well layer and the barrier layer of the second active layer are C and D, respectively, where 2.0≤B≤D≤A≤C≤3.0. For example, the refractive index coefficients of the well layer and the barrier layer of the first active layer are A=2.8 and B=2.0, respectively, and the refractive index coefficients of the well layer and the barrier layer of the second active layer are C=3.0 and D=2.5, respectively.

[0090] In some embodiments, the dielectric constants of the well layer and the barrier layer of the first active layer are E and F, respectively, and the dielectric constants of the well layer and the barrier layer of the second active layer are G and H, respectively, where 8≤G≤E≤H≤F≤12. For example, the dielectric constants of the well layer and the barrier layer of the first active layer are E=9 and F=12, respectively, and the dielectric constants of the well layer and the barrier layer of the second active layer are G=8 and H=10, respectively.

[0091] In some embodiments, the piezoelectric polarization coefficients of the well layer and the barrier layer of the first active layer are I and J, respectively, and the piezoelectric polarization coefficients of the well layer and the barrier layer of the second active layer are K and L, respectively, where 0.7≤J≤L≤I≤K≤1.0. For example, the piezoelectric polarization coefficients of the well layer and the barrier layer of the first active layer are I=0.85 and J=0.7, respectively, and the piezoelectric polarization coefficients of the well layer and the barrier layer of the second active layer are K=1.0 and L=0.80, respectively.

[0092] In some embodiments of the present specification, by setting the dielectric constants of the well layer and the barrier layer of the first active layer to E and F, respectively, and the dielectric constants of the well layer and the barrier layer of the second active layer to G and H, respectively, where 8≤G≤E≤H≤F≤12; and setting the piezoelectric polarization coefficients of the well layer and the barrier layer of the first active layer to I and J, respectively, and the piezoelectric polarization coefficients of the well layer and the barrier layer of the second active layer to K and L, respectively, where 0.7≤J≤L≤I≤K≤1.0, the photon degeneracy of the active layer and the symmetry of the conduction band and the heavy hole band of the semiconductor laser can be further improved. Under the same injection current, the quasi-Fermi levels of the conduction band and the heavy hole band will enter their respective energy bands with equal probability, further reducing the threshold current density required to achieve population inversion, making the stimulated radiation of the laser greater than the spontaneous radiation, further improving the coherence, confinement factor and slope efficiency of the transverse mode, and further reducing the number of longitudinal modes and inter-mode variation, further improving the longitudinal mode temporal coherence and far-field FFP image quality, beam quality factor and focus spot resolution.

[0093] In some embodiments, the refractive index coefficient, dielectric constant, and piezoelectric polarization coefficient of the first active layer all exhibit a W-shaped distribution.

[0094] The W-shaped distribution of the refractive index coefficient means that, among the multiple regions divided into the first active layer, the calculated refractive index coefficient in each region has a W-shaped distribution. The first active layer can be divided into the multiple regions in various ways. For example, the first active layer can be divided into m1 regions in equal proportion, where m1 ≥ 2 and m1 is a positive integer.

[0095] The W-shaped distribution of the dielectric constant and the W-shaped distribution of the piezoelectric polarization coefficient have similar meanings to the W-shaped distribution of the refractive index coefficient. Please refer to the above description for details.

[0096] In some embodiments, the refractive index coefficient, dielectric constant, and piezoelectric polarization coefficient of the second active layer all exhibit an M-type distribution.

[0097] An M-shaped distribution of the refractive index coefficient means that, among the multiple regions divided into the second active layer, the calculated refractive index coefficient in each region has an M-shaped distribution. The second active layer can be divided into the multiple regions in various ways. For example, the second active layer can be divided into m1 regions in equal proportion, where m1 ≥ 2 and m1 is a positive integer.

[0098] The M-type distribution of the dielectric constant and the M-type distribution of the piezoelectric polarization coefficient have similar meanings to the M-type distribution of the refractive index coefficient. Please refer to the above description for details.

[0099] In some embodiments of the present specification, by having the refractive index coefficient, dielectric constant and piezoelectric polarization coefficient of the first active layer all present a W-type distribution, and the refractive index coefficient, dielectric constant and piezoelectric polarization coefficient of the second active layer all present an M-type distribution, the photon degeneracy of the active layer and the symmetry of the conduction band and heavy hole band of the semiconductor laser can be further improved. Under the same injected current, the quasi-Fermi levels of the conduction band and the heavy hole band will enter their respective energy bands with equal probability, further reducing the threshold current density required to achieve population inversion, making the stimulated radiation of the laser greater than the spontaneous radiation, further improving the coherence, confinement factor and slope efficiency of the transverse mode, and further reducing the number of longitudinal modes and inter-mode variations, further improving the longitudinal mode temporal coherence and far-field FFP image quality, beam quality factor and focused spot resolution.

[0100] Figure 7 is a TEM image of the upper and lower waveguide layers of a semiconductor laser obtained when the TEM size is 200 nm according to some embodiments of this specification. Figure 8 is a TEM image of the upper confinement layer of a semiconductor laser obtained when the TEM size is 100 nm according to some embodiments of this specification.

[0101] As shown in FIG. 7-8 , in some embodiments, the upper waveguide layer 104 may be an upper waveguide layer 104 that suppresses light absorption loss.

[0102] In some embodiments, the upper waveguide layer 104 is composed of at least one of GaN, InGaN, InN, AlInN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond.

[0103] In some embodiments, the thickness of the upper waveguide layer 104 is between 200 angstroms and 8000 angstroms.

[0104] In some embodiments, the conduction band effective state density distribution, electron affinity distribution, and breakdown field strength distribution of the upper waveguide layer 104 are all arc-shaped.

[0105] The conduction band effective density is the distribution density of crystal electrons in the unit wave vector space of the conduction band.

[0106] The conduction band effective density of states distribution refers to the distribution of the conduction band effective density of states within each of the multiple regions defined by the upper waveguide layer. The upper waveguide layer can be divided into multiple regions in various ways. For example, the upper waveguide layer can be divided into m2 regions in equal proportion, where m2 ≥ 2 and m2 is a positive integer.

[0107] The breakdown field strength refers to the maximum electric field strength that a certain area on the upper waveguide layer can withstand to avoid breakdown under the action of the electric field.

[0108] The breakdown field intensity distribution refers to the distribution of the breakdown field intensity in each of the multiple regions divided by the upper waveguide layer.

[0109] In some embodiments, the conduction band effective state density distribution corresponds to the curve distribution of the fifth function, and the fifth function is y=log v x(0<v<1).

[0110] In some embodiments, the electron affinity distribution corresponds to a curve distribution of a sixth function, where the sixth function is y=log w x(w>1).

[0111] In some embodiments, the breakdown field intensity distribution corresponds to the curve distribution of the seventh function, and the seventh function is y=log z x(z>1); wherein, 0<v<1<w<z<500.

[0112] In some embodiments of the present specification, the conduction band effective state density distribution, electron affinity energy distribution, and breakdown field strength distribution of the upper waveguide layer are arc-shaped, thereby forming an optical field isolation and confinement zone, blocking the diffusion of the optical field to the upper confinement layer, thereby reducing the impurity light absorption loss and defect light absorption loss of the upper confinement layer; at the same time, by regulating the conduction band effective state density distribution, electron affinity energy distribution, and breakdown field strength distribution of the upper waveguide layer to have an arc-shaped distribution, the refractive index dispersion can be regulated, the refractive index fluctuation of the semiconductor laser at a high carrier concentration can be reduced, the carrier light absorption loss and the waveguide structure sidewall scattering loss can be reduced, and the light absorption loss of the semiconductor laser can be reduced, thereby improving the confinement factor and optical power.

[0113] The lower waveguide layer 102 can serve as a light transmission channel on the semiconductor laser.

[0114] The upper confinement layer 105 can be used to confine the injection of electrons and holes and the propagation of light in the semiconductor laser.

[0115] In some embodiments, the lower waveguide layer 102 and the upper confinement layer 105 are respectively composed of at least one material selected from the group consisting of GaN, InGaN, InN, AlInN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond.

[0116] In some embodiments, the thickness of the lower waveguide layer 102 is between 10 angstroms and 50,000 angstroms.

[0117] In some embodiments, the thickness of the upper confinement layer 105 is between 10 angstroms and 80,000 angstroms.

[0118] The substrate 100 refers to a material base used to manufacture a semiconductor laser. For example, the substrate can be a wafer made of a semiconductor single crystal material.

[0119] In some embodiments, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, Cu, W, Mo, TiW, GaSb, InSb, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x , any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, MgO, spinel, ZrB2, diamond, LiAlO2 and LiGaO2 composite substrates.

[0120] The following is a comparison table of the variation ranges between various blue laser items of conventional lasers and the semiconductor lasers of this specification:

[0121] From the table above, we can see that compared with the traditional laser, the threshold current density of the semiconductor laser in this specification is increased from 2.4 (kA / cm 2 ) improved to 0.87(kA / cm 2 ), 1000H aging light attenuation improved from 22% to 4%, internal optical loss improved from 17.2 (cm -1 ) improved to 11.6 (cm -1 ), the focus spot resolution is reduced from more than 200nm to less than 40nm, the slope efficiency is increased from 0.8 (W / A) to 1.76 (W / A), and the beam quality factor is 3.7M 2 Reduced to 2.35M 2, the optical power is increased from 5.2W to 12.9W and the limitation factor is increased from 1.50% to 2.89%, thereby suppressing the Auger non-radiative recombination efficiency, reducing the heat generated by non-radiative recombination loss and free carrier absorption loss, reducing the heat accumulation in the active layer, improving thermal conductivity and heat dissipation, and improving the aging light decay and focused spot resolution of the semiconductor laser.

[0122] The above shows and describes the basic principles, main features, and advantages of this specification. Those skilled in the art should understand that this specification is not limited to the above-described embodiments. The above-described embodiments and descriptions are merely illustrative of the principles of this specification. Various changes and improvements may be made to this specification without departing from the spirit and scope of this specification. Such changes and improvements are intended to fall within the scope of this specification. The scope of protection claimed in this specification is defined by the appended claims and their equivalents.

[0123] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0124] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0125] Similarly, it should be noted that, in order to simplify the descriptions disclosed in this specification and thus facilitate understanding of one or more embodiments, the foregoing descriptions of embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single embodiment disclosed above.

[0126] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0127] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0128] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A semiconductor laser, comprising, from bottom to top, 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), characterized in that: The lower confinement layer (101) is composed of at least one material selected from the group consisting of AlInGaN, AlInN, AlGaN, InN, AlN, InGaN and GaN, and the thickness of the lower confinement layer (101) is x, wherein 10 angstroms ≤ x ≤ 90,000 angstroms; the lower confinement layer (101) includes a first lower confinement layer (101a), a second lower confinement layer (101b) and a third lower confinement layer (101c).

2. The semiconductor laser according to claim 1, characterized in that The thermal conductivities of the first lower confinement layer (101a), the second lower confinement layer (101b) and the third lower confinement layer (101c) are a, b and c, respectively, wherein 2.5 (10 -6 / K)≤b≤a≤c≤5.5(10 -6 / K); the electron effective masses of the first lower confinement layer (101a), the second lower confinement layer (101b) and the third lower confinement layer (101c) are d, e and f respectively, wherein 200me≤e≤f≤d≤400me; the Philips ionization degrees of the first lower confinement layer (101a), the second lower confinement layer (101b) and the third lower confinement layer (101c) are g, h and i respectively, wherein 3≤i≤g≤h≤4.

3. The semiconductor laser according to claim 1, characterized in that The ratio of In element content / Mg element content and the ratio of Si element content / Mg element content of the second lower limiting layer (101b) have a "∩" type distribution, and the ratio of Al element content / Mg element content of the second lower limiting layer (101b) has a "∪" type distribution.

4. The semiconductor laser according to claim 1, characterized in that The thermal conductivity distribution and the electron effective mass distribution of the second lower confinement layer (101b) have a "∪" type distribution, and the Philips ionization degree distribution and the electron affinity distribution of the second lower confinement layer (101b) have a "∩" type distribution.

5. The semiconductor laser according to claim 4, characterized in that The thermal conductivity distribution of the second lower confinement layer (101b) corresponds to the curve distribution of the first function, and the first function is y=ix 2 +jx+k(i>0), the electron effective mass distribution of the second lower confinement layer (101b) corresponds to the curve distribution of the second function, and the second function is y=mx 2 +nx+o(m>0), the Philips ionization degree distribution of the second lower confinement layer (101b) corresponds to the curve distribution of the third function, and the third function is y=px 2 +qx+r(p<0), the electron affinity distribution of the second lower confinement layer (101b) corresponds to the curve distribution of the fourth function, and the fourth function is y=sx 2 +tx+u(s<0), where s<p<0<i≤m, j, k, n, o, q, r, t and u are arbitrary preset values.

6. The semiconductor laser according to claim 1, characterized in that The active layer (103) is a periodic structure composed of well layers and barrier layers, and the periodic structure includes 1 to 3 groups of the well layers and barrier layers; the well layers and barrier layers are respectively GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InA The present invention is composed of at least one material selected from the group consisting of s, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN and diamond, the thickness of the well layer is 10 angstroms to 120 angstroms; the thickness of the barrier layer is 10 angstroms to 200 angstroms; the refractive index coefficient of the well layer is greater than or equal to the refractive index coefficient of the barrier layer; the dielectric constant of the well layer is greater than or equal to the dielectric constant of the barrier layer; the piezoelectric polarization coefficient of the well layer is greater than or equal to the piezoelectric polarization coefficient of the barrier layer.

7. The semiconductor laser according to claim 6, characterized in that The active layer (103) comprises a first active layer and a second active layer; the refractive index coefficients of the well layer and the barrier layer of the first active layer are A and B respectively, and the refractive index coefficients of the well layer and the barrier layer of the second active layer are C and D respectively, wherein 2.0≤B≤D≤A≤C≤3.0; the dielectric constants of the well layer and the barrier layer of the first active layer are E and F respectively, and the dielectric constants of the well layer and the barrier layer of the second active layer are G and H respectively, wherein 8≤G≤E≤H≤F≤12; the piezoelectric polarization coefficients of the well layer and the barrier layer of the first active layer are I and J respectively, and the piezoelectric polarization coefficients of the well layer and the barrier layer of the second active layer are K and L respectively, wherein 0.7≤J≤L≤I≤K≤1.

0.

8. The semiconductor laser according to claim 6, characterized in that The refractive index coefficient, dielectric constant and piezoelectric polarization coefficient of the first active layer are all in W-type distribution, and the refractive index coefficient, dielectric constant and piezoelectric polarization coefficient of the second active layer are all in M-type distribution.

9. The semiconductor laser according to claim 1, characterized in that The upper waveguide layer (104) is an upper waveguide layer (104) for suppressing light absorption loss; the upper waveguide layer (104) is composed of at least one material selected from GaN, InGaN, InN, AlInN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN and diamond, and the thickness of the upper waveguide layer (104) is 200 angstroms to 8000 angstroms; the conduction band effective state density distribution, electron affinity energy distribution and breakdown field strength distribution of the upper waveguide layer (104) are all arc-shaped distributions; the conduction band effective state density distribution corresponds to the curve distribution of the fifth function, and the fifth function is y=log v x(0<v<1); the electron affinity distribution corresponds to the curve distribution of the sixth function, and the sixth function is y=log w x(w>1); the breakdown field intensity distribution corresponds to the curve distribution of the seventh function, the seventh function is y=log z x(z>1); wherein, 0<v<1<w<z<500.

10. A semiconductor laser according to claim 1, characterized in that: The lower waveguide layer (102) and the upper confinement layer (105) are respectively made of GaN, InGaN, InN, AlInN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, The substrate (100) is composed of at least one material selected from SiC, Ga2O3, BN and diamond, the thickness of the lower waveguide layer (102) is 10 angstroms to 50,000 angstroms; the thickness of the upper confinement layer (105) is 10 angstroms to 80,000 angstroms; the substrate (100) comprises sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, Cu, W, Mo, TiW, GaSb, InSb, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x , any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, MgO, spinel, ZrB2, diamond, LiAlO2 and LiGaO2 composite substrates.

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