Nitride semiconductor laser with light beam quality regulation and control layer

Abstract

The invention discloses a nitride semiconductor laser with a light beam quality regulation and control layer, which sequentially comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper limiting layer from bottom to top, and is characterized in that the lower limiting layer comprises a first lower limiting layer, a second lower limiting layer and a third lower limiting layer; the first lower limiting layer and the third lower limiting layer are any one or any combination of AlGaN, GaN, AlInGaN and AlInN, and the second lower limiting layer is any one or any combination of InGaN, AlInGaN and AlInN; a first light beam quality regulation and control layer is arranged between the first lower limiting layer and the second lower limiting layer, a second light beam quality regulation and control layer is arranged between the second lower limiting layer and the third lower limiting layer, and the first light beam quality regulation and control layer and the second light beam quality regulation and control layer form a light beam quality regulation and control layer. Substrate mode leakage and stray light can be inhibited, the light spot divergence angle is improved, the high-order transverse mode generation probability is reduced, and the light beam quality factor and light beam convergence are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor optoelectronic devices, and in particular relates to a nitride semiconductor laser with a beam quality control layer. Background Art

[0002] Lasers are widely used in laser display, laser TV, laser projector, communication, medical treatment, weapons, guidance, ranging, spectral analysis, cutting, precision welding, high-density optical storage and other fields. There are many types of lasers, and their classification methods are also diverse, mainly solid, gas, liquid, semiconductor and dye types of lasers; compared with other types of lasers, all-solid-state semiconductor lasers have the advantages of small size, high efficiency, light weight, good stability, long life, simple and compact structure, and miniaturization. There are big differences between lasers and nitride semiconductor light-emitting diodes. 1) Lasers are generated by stimulated radiation of carriers, with a small half-width of the spectrum and high brightness. The output power of a single laser can be in the W level, while nitride semiconductor light-emitting diodes are spontaneous radiation, and the output power of a single light-emitting diode is in the mW level; 2) The current density of the laser reaches KA / cm2, 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) Light-emitting diodes The tube spontaneously radiates, without any external influence, and it is incoherent light that transitions from high energy level to low energy level, while the laser is stimulated transition radiation, and the energy of the induced photon should be equal to the difference in energy levels of the electron transition, producing photons and induced photons that are completely coherent light; 4) Different principles: Under the action of external voltage, the light-emitting diode produces radiation recombination and luminescence when electron holes transition to the quantum well or pn junction, while the laser needs the lasing conditions to be met before it can be lased. The carrier inversion distribution in the active area must be met, and the stimulated radiation light oscillates back and forth in the resonant cavity. The propagation in the gain medium amplifies the light, meets the threshold condition so that the gain is greater than the loss, and finally outputs the laser.

[0003] Nitride semiconductor lasers have the following problems: The beam quality propagation factor is the product of the laser beam waist and the far-field divergence angle, which describes the beam quality parameters and is a specific representation of the laser's high brightness and coherence. The closer the beam is to a Gaussian beam, the higher the quality. The lower confinement layer has a deviated confinement effect, the laser spot divergence angle is small, and the far-field image does not satisfy the Gaussian pattern in the c-axis direction of the laser epitaxial layer. The spot quality is poor and cannot be focused; the light field is dissipated, and the light field mode leaks to the substrate to form a standing wave, which will lead to low substrate mode suppression efficiency and poor far-field image FFP quality.

[0004] Therefore, the present invention provides a nitride semiconductor laser with a beam quality control layer to solve the problems raised by the above-mentioned background technology. Summary of the invention

[0005] In view of the problems raised by the above background technology, the purpose of the present invention is to provide a nitride semiconductor laser with a beam quality control layer, which can improve the beam quality factor and beam convergence.

[0006] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0007] A nitride semiconductor laser with a beam quality control layer comprises, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper confinement layer, wherein the lower confinement layer comprises a first lower confinement layer, a second lower confinement layer and a third lower confinement layer, wherein the first lower confinement layer and the third lower confinement layer are any one or any combination of AlGaN, GaN, AlInGaN and AlInN, and the second lower confinement layer is any one or any combination of InGaN, AlInGaN and AlInN; a first beam quality control layer is provided between the first lower confinement layer and the second lower confinement layer, a second beam quality control layer is provided between the second lower confinement layer and the third lower confinement layer, and the first beam quality control layer and the second beam quality control layer constitute a beam quality control layer.

[0008] It is further defined that the Al element concentration of the first lower limiting layer and the third lower limiting layer shows a gradual change trend toward the substrate, and the gradual change angle is 0 to 30°; the peak position of the In element concentration of the second lower limiting layer shows a sudden change trend toward the substrate, and the sudden change angle is 15 to 60°; the peak position of the In element concentration of the first beam quality control layer shows a sudden downward trend toward the substrate, and the sudden downward angle is 45 to 90°, and the valley position of the Al element concentration shows a sudden upward trend toward the substrate, and the sudden upward angle is 30 to 60°; the valley position of the In element concentration of the second beam quality control layer shows a sudden upward trend toward the substrate, and the sudden upward angle is 45 to 90°, and the peak position of the Al element concentration shows a sudden downward trend toward the substrate, and the sudden downward angle is 30 to 60°; the angle is the tangent inclination angle along the curve;

[0009] The gradual change angle of the Al element concentration of the first lower limiting layer ≤ the gradual change angle of the Al element concentration of the third lower limiting layer ≤ the sudden decrease angle of the In element concentration of the second lower limiting layer ≤ the sudden decrease angle of the Al element concentration of the second beam quality control layer ≤ the sudden increase angle of the Al element concentration of the first beam quality control layer ≤ the sudden increase angle of the In element concentration of the second beam quality control layer ≤ the sudden decrease angle of the In element concentration of the first beam quality control layer.

[0010] It is further defined that the descending angle of the refractive index peak position of the first beam quality control layer toward the substrate is a sudden descending angle, the angle is α, wherein: 45°≤α≤90°; the rising angle of the refractive index valley position of the second beam quality control layer toward the substrate is a sudden rising angle, the angle is β, wherein: 0°≤β≤45°;

[0011] The refractive index peak position of the second lower confinement layer decreases at an angle of abrupt decrease toward the substrate, and the angle is γ, wherein: 45°≤γ≤90°; the refractive index of the first lower confinement layer decreases at a gradual change angle toward the substrate, and the angle is θ, wherein: 0°≤θ≤30°;

[0012] The refractive index of the third lower limiting layer changes gradually toward the substrate at an angle of φ, wherein: 0°≤φ≤30°; the gradually changing refractive index angle of the third lower limiting layer ≤ the gradually changing refractive index angle of the first lower limiting layer ≤ the suddenly decreasing refractive index angle of the second lower limiting layer ≤ the suddenly increasing refractive index angle of the second beam quality control layer ≤ the suddenly decreasing refractive index angle of the first beam quality control layer.

[0013] It is further defined that the descending angle of the peak position of the breakdown field intensity of the first beam quality control layer toward the substrate is a sudden descending angle, the angle is ω, wherein: 45°≤ω≤90°; the rising angle of the valley position of the breakdown field intensity of the second beam quality control layer toward the substrate is a sudden rising angle, the angle is δ, wherein: 0°≤δ≤45°;

[0014] The peak position of the breakdown field strength of the second lower confinement layer has a sudden drop angle toward the substrate, the angle being ψ, where: 45°≤ψ≤90°; the breakdown field strength of the first lower confinement layer has a gradual change angle toward the substrate, the angle being ε, where: 0°≤ε≤30°; the breakdown field strength of the third lower confinement layer has a gradual change angle toward the substrate, the angle being σ, where: 0°≤σ≤30°;

[0015] The breakdown field intensity gradual change angle of the third lower limiting layer ≤ the breakdown field intensity gradual change angle of the first lower limiting layer ≤ the sudden drop angle of the breakdown field intensity of the second lower limiting layer ≤ the sudden rise angle of the breakdown field intensity of the second beam quality control layer ≤ the sudden drop angle of the breakdown field intensity of the first beam quality control layer.

[0016] It is further defined that the rising angle of the valley position of the polarization optical phonon energy of the first beam quality control layer toward the substrate is a sudden rising angle, and the angle is μ, wherein: 45°≤μ≤90°; the falling angle of the peak position of the polarization optical phonon energy of the second beam quality control layer toward the substrate is a sudden falling angle, and the angle is ρ, wherein: 0°≤ρ≤45°;

[0017] The rising angle of the valley position of the polarization phonon energy of the second lower confinement layer toward the substrate is a sudden rising angle, the angle is τ, wherein: 45°≤τ≤90°; the polarization phonon energy of the first lower confinement layer toward the substrate is a gradual changing angle, the angle is υ, wherein: 0°≤υ≤30°; the polarization phonon energy of the third lower confinement layer toward the substrate is a gradual changing angle, the angle is χ, wherein: 0°≤χ≤30°;

[0018] The slowly changing angle of polaritonic phonon energy of the third lower confinement layer is ≤ the slowly changing angle of polaritonic phonon energy of the first lower confinement layer ≤ the suddenly rising angle of polaritonic phonon energy of the second lower confinement layer ≤ the suddenly falling angle of polaritonic phonon energy of the second beam quality control layer ≤ the suddenly rising angle of polaritonic phonon energy of the first beam quality control layer.

[0019] It is further defined that the rising angle of the valley position of the longitudinal sound velocity of the first beam quality control layer toward the substrate is a sudden rising angle, the angle is κ, wherein: 45°≤κ≤90°; the falling angle of the peak position of the longitudinal sound velocity of the second beam quality control layer toward the substrate is a sudden falling angle, the angle is ζ, wherein: 0°≤ζ≤45°;

[0020] The rising angle of the valley position of the longitudinal sound velocity of the second lower limiting layer towards the substrate is a sudden rising angle, which is π, wherein: 45°≤π≤90°; the longitudinal sound velocity of the first lower limiting layer towards the substrate is a gradual changing angle, which is ν, wherein: 0°≤ν≤30°; the longitudinal sound velocity of the third lower limiting layer towards the substrate is a gradual changing angle, which is ξ, wherein: 0°≤ξ≤30°;

[0021] The slow change angle of the longitudinal sound velocity of the third lower limiting layer is ≤ the slow change angle of the longitudinal sound velocity of the first lower limiting layer ≤ the sudden rise angle of the longitudinal sound velocity of the second lower limiting layer ≤ the sudden decrease angle of the longitudinal sound velocity of the second beam quality control layer ≤ the sudden rise angle of the longitudinal sound velocity of the first beam quality control layer.

[0022] It is further defined that the sudden decrease angle of the refractive index change, the sudden decrease angle of the breakdown field intensity, the sudden increase angle of the polarization optical phonon energy, and the sudden increase angle of the longitudinal sound velocity of the first beam quality control layer have the following relationship: 45°≤μ≤κ≤α≤ω≤90°; the sudden increase angle of the refractive index change, the sudden increase angle of the breakdown field intensity, the sudden decrease angle of the polarization optical phonon energy, and the sudden decrease angle of the longitudinal sound velocity of the second beam quality control layer have the following relationship: 45°≤ρ≤ζ≤β≤δ≤90°.

[0023] It is further defined that the refractive index distribution of the first beam quality control layer has a function y=A*e x / lnx+B curve distribution, the refractive index distribution of the second beam quality control layer has the function y=C*lnx / e x +D curve distribution; the breakdown field intensity distribution of the first beam quality control layer has a function y=E*e x / lnx+F curve distribution, the breakdown field intensity distribution of the second beam quality control layer has the function y=G*lnx / e x +H curve distribution;

[0024] The radiation recombination coefficient distribution of the first beam quality control layer has a function y=J*e x / lnx+K curve distribution, the radiation recombination coefficient distribution of the second beam quality control layer has the function y=L*lnx / e x +M curve distribution; the saturated electron drift rate distribution of the first beam quality control layer has a function y=N*e x / lnx+P curve distribution, the saturated electron drift rate distribution of the second beam quality control layer has the function y=Q*lnx / e x +R curve distribution.

[0025] It is further defined that the refractive index distribution, breakdown field intensity distribution, radiation recombination coefficient distribution, and saturated electron drift rate distribution of the first beam quality control layer have the following relationship: K≤B≤F≤P; the refractive index distribution, breakdown field intensity distribution, radiation recombination coefficient distribution, and saturated electron drift rate distribution of the second beam quality control layer have the following relationship: M≤D≤H≤R.

[0026] It is further defined that the beam quality control layer is any one or any combination of InGaN, InN, AlInGaN, GaN, AlGaN, InGaN / GaN superlattice, InGaN / AlInN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, GaN / AlInN superlattice, GaN / AlGaN superlattice, InGaN / InGaN superlattice, AlInGaN / AlInGaN superlattice or any combination with GaN;

[0027] The active layer is a periodic structure composed of a well layer and a barrier layer, the number of periods is 3≥m≥1, and the well layer is any one or any combination 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 The barrier layer is any one or any combination 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, and its thickness is 10 to 200 angstroms;

[0028] The lower limiting layer, the lower waveguide layer, the upper waveguide layer and the upper limiting layer are 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, The substrate is a single crystal substrate, which is any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, sapphire / SiNx, sapphire / SiO2 / SiNx composite substrate, sapphire / SiNx / SiO2 composite substrate, magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

[0029] Beneficial effects of the present invention:

[0030] 1. This scheme arranges a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper limiting layer; designs that the Al element concentration of the first lower limiting layer and the third lower limiting layer changes slowly toward the substrate; the peak position of the In element concentration of the second lower limiting layer changes suddenly toward the substrate; the peak position of the In element concentration of the first beam quality control layer changes suddenly downward toward the substrate, and the position of the valley value of the Al element concentration changes suddenly upward toward the substrate; the valley value position of the In element concentration of the second beam quality control layer changes suddenly upward toward the substrate, and the peak position of the Al element concentration changes suddenly downward toward the substrate, thereby suppressing substrate mode leakage and stray light, improving the spot divergence angle and reducing the probability of generating high-order transverse modes, so that the far-field image satisfies the Gaussian pattern in the c-axis direction, and improving the beam quality factor and beam convergence.

[0031] 2. By designing the gradual variation angle of the Al element concentration of the first lower limiting layer ≤ the gradual variation angle of the Al element concentration of the third lower limiting layer ≤ the sudden decrease angle of the In element concentration of the second lower limiting layer ≤ the sudden decrease angle of the Al element concentration of the second beam quality control layer ≤ the sudden increase angle of the Al element concentration of the first beam quality control layer ≤ the sudden increase angle of the In element concentration of the second beam quality control layer ≤ the sudden decrease angle of the In element concentration of the first beam quality control layer, the refractive index difference and the refractive index gradient are improved, the horizontal expansion angle is improved, the mode hopping in the vertical direction is suppressed, the FFP far-field image with a low aspect ratio is achieved, and the far-field ripple field image is formed.

[0032] 3. Through the refractive index distribution, breakdown field intensity distribution, radiation recombination coefficient distribution, and saturated electron drift rate distribution of the first beam quality control layer and the second beam quality control layer, the longitudinal diffusion of the light field is controlled, carriers are effectively collected, the local confinement factor of the light field is improved, and the fast axis divergence angle and cavity surface power density are reduced, the cavity surface load is reduced, the probability of COD optical catastrophe is reduced, and the local hole burning effect caused by the increase in refractive index is suppressed, the beam distortion is reduced, and the beam quality factor is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0034] Figure 1 A SIMS secondary ion mass spectrum of an embodiment of a nitride semiconductor laser with a beam quality control layer according to the present invention;

[0035] Figure 2 It is a schematic structural diagram of an embodiment of a nitride semiconductor laser with a beam quality control layer according to the present invention;

[0036] The main component symbols are explained as follows: substrate 100; lower confinement layer 101; lower waveguide layer 102; active layer 103; upper waveguide layer 104; electron blocking layer 105; upper confinement layer 106; beam quality control layer 107, first lower confinement layer 101a, second lower confinement layer 101b, third lower confinement layer 101c, first beam quality control layer 107a, second beam quality control layer 107b. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0039] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] Embodiment 1: Figure 1 and Figure 2As shown, a nitride semiconductor laser with a beam quality control layer of the present invention 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, an electron blocking layer 105 and an upper confinement layer 106, wherein 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, wherein the first lower confinement layer 101a and the third lower confinement layer 101c are AlGaN, and the second lower confinement layer 101b is InGaN; a first beam quality control layer 107a is provided between the first lower confinement layer 101a and the second lower confinement layer 101b, a second beam quality control layer 107b is provided between the second lower confinement layer 101b and the third lower confinement layer 101c, and the first beam quality control layer 107a and the second beam quality control layer 107b constitute a beam quality control layer 107.

[0041] Preferably, the Al element concentration of the first lower limiting layer 101a and the third lower limiting layer 101c presents a gradual change trend toward the substrate 100, with a gradual change angle of 0°; the peak position of the In element concentration of the second lower limiting layer 101b presents a sudden change trend toward the substrate 100, with a sudden change angle of 15°; the peak position of the In element concentration of the first beam quality control layer 107a presents a sudden downward trend toward the substrate 100, with a sudden downward angle of 45°, and the valley position of the Al element concentration presents a sudden upward trend toward the substrate 100, with a sudden upward angle of 30°; the valley position of the In element concentration of the second beam quality control layer 107b presents a sudden upward trend toward the substrate 100, with a sudden upward angle of 45°, and the peak position of the Al element concentration presents a sudden downward trend toward the substrate 100, with a sudden downward angle of 30°; the angle is the tangent inclination angle along the curve;

[0042] The gradual change angle of the Al element concentration of the first lower limiting layer 101a ≤ the gradual change angle of the Al element concentration of the third lower limiting layer 101c ≤ the sudden decrease angle of the In element concentration of the second lower limiting layer 101b ≤ the sudden decrease angle of the Al element concentration of the second beam quality control layer 107b ≤ the sudden increase angle of the Al element concentration of the first beam quality control layer 107a ≤ the sudden increase angle of the In element concentration of the second beam quality control layer 107b ≤ the sudden decrease angle of the In element concentration of the first beam quality control layer 107a.

[0043] Preferably, the descending angle of the refractive index peak position of the first beam quality control layer 107a toward the substrate is a sudden descending angle, and the angle is α, wherein: α is 45°; the rising angle of the refractive index valley position of the second beam quality control layer 107b toward the substrate is a sudden rising angle, and the angle is β is 0°;

[0044] The refractive index peak position of the second lower confinement layer 101b decreases at a sudden drop angle toward the substrate, and the angle γ is 45°; the refractive index of the first lower confinement layer 101a decreases at a gradual drop angle toward the substrate, and the angle θ is 0°;

[0045] The refractive index of the third lower limiting layer 101c changes gradually toward the substrate, and the angle φ is 0°; the gradually changing angle of the refractive index of the third lower limiting layer 101c is ≤ the gradually changing angle of the refractive index of the first lower limiting layer 101a ≤ the sudden decrease angle of the refractive index of the second lower limiting layer 101b ≤ the sudden increase angle of the refractive index of the second beam quality control layer 107b ≤ the sudden decrease angle of the refractive index of the first beam quality control layer 107a.

[0046] Preferably, the falling angle of the peak position of the breakdown field intensity of the first beam quality control layer 107a toward the substrate 100 is a sudden falling angle, and the angle ω is 45°; the rising angle of the valley position of the breakdown field intensity of the second beam quality control layer 107b toward the substrate 100 is a sudden rising angle, and the angle δ is 0°;

[0047] The peak position of the breakdown field strength of the second lower confinement layer 101b decreases at a sudden decrease angle toward the substrate 100, and the angle ψ is 45°; the breakdown field strength of the first lower confinement layer 101a decreases at a gradual change angle toward the substrate 100, and the angle ε is 0°; the breakdown field strength of the third lower confinement layer 101c decreases at a gradual change angle toward the substrate 100, and the angle σ is 0°;

[0048] The breakdown field strength gradual change angle of the third lower confinement layer 101c ≤ the breakdown field strength gradual change angle of the first lower confinement layer 101a ≤ the sudden decrease angle of the breakdown field strength of the second lower confinement layer 101b ≤ the sudden increase angle of the breakdown field strength of the second beam quality control layer 107b ≤ the sudden decrease angle of the breakdown field strength of the first beam quality control layer 107a.

[0049] Preferably, the rising angle of the valley position of the polarization optical phonon energy of the first beam quality control layer 107a toward the substrate 100 is a sudden rising angle, and the angle μ is 45°; the falling angle of the peak position of the polarization optical phonon energy of the second beam quality control layer 107b toward the substrate 100 is a sudden falling angle, and the angle ρ is 0°;

[0050] The rising angle of the valley position of the polarization optical phonon energy of the second lower confinement layer 101b toward the substrate 100 is a sudden rising angle, and the angle τ is 45°; the polarization optical phonon energy of the first lower confinement layer 101a is a gradual changing angle toward the substrate 100, and the angle υ is 0°; the polarization optical phonon energy of the third lower confinement layer 101c is a gradual changing angle toward the substrate 100, and the angle χ is 0°;

[0051] The gradual change angle of polarization phonon energy of the third lower confinement layer 101c is ≤ the gradual change angle of polarization phonon energy of the first lower confinement layer 101a ≤ the sudden rise angle of polarization phonon energy of the second lower confinement layer 101b ≤ the sudden decrease angle of polarization phonon energy of the second beam quality control layer 107b ≤ the sudden rise angle of polarization phonon energy of the first beam quality control layer 107a.

[0052] Preferably, the rising angle of the valley position of the longitudinal sound velocity of the first beam quality control layer 107a toward the substrate 100 is a sudden rising angle, and the angle κ is 45°; the falling angle of the peak position of the longitudinal sound velocity of the second beam quality control layer 107b toward the substrate 100 is a sudden falling angle, and the angle ζ is 0°;

[0053] The rising angle of the valley position of the longitudinal sound velocity of the second lower limiting layer 101b towards the substrate 100 is a sudden rising angle, and the angle π is 45°; the longitudinal sound velocity of the first lower limiting layer 101a is a gradual changing angle towards the substrate 100, and the angle ν is 0°; the longitudinal sound velocity of the third lower limiting layer 101c is a gradual changing angle towards the substrate 100, and the angle ξ is 0°;

[0054] The gradual change angle of the longitudinal sound velocity of the third lower limiting layer 101c ≤ the gradual change angle of the longitudinal sound velocity of the first lower limiting layer 101a ≤ the sudden rise angle of the longitudinal sound velocity of the second lower limiting layer 101b ≤ the sudden decrease angle of the longitudinal sound velocity of the second beam quality control layer 107b ≤ the sudden rise angle of the longitudinal sound velocity of the first beam quality control layer 107a.

[0055] Preferably, the sudden decrease angle of the refractive index change, the sudden decrease angle of the breakdown field intensity, the sudden increase angle of the polarization optical phonon energy, and the sudden increase angle of the longitudinal sound velocity of the first beam quality control layer 107a have the following relationship: 45°≤μ≤κ≤α≤ω≤90°; the sudden increase angle of the refractive index change, the sudden increase angle of the breakdown field intensity, the sudden decrease angle of the polarization optical phonon energy, and the sudden decrease angle of the longitudinal sound velocity of the second beam quality control layer 107b have the following relationship: 45°≤ρ≤ζ≤β≤δ≤90°.

[0056] like Figure 1As shown, preferably, the refractive index distribution of the first beam quality control layer 107a has a function y=A*e x / lnx+B curve distribution, the refractive index distribution of the second beam quality control layer 107b has a function y=C*lnx / e x +D curve distribution; the breakdown field intensity distribution of the first beam quality control layer 107a has a function y=E*e x / lnx+F curve distribution, the breakdown field intensity distribution of the second beam quality control layer 107b has a function y=G*lnx / e x +H curve distribution;

[0057] The radiation recombination coefficient distribution of the first beam quality control layer 107a has a function y=J*e x / lnx+K curve distribution, the radiation recombination coefficient distribution of the second beam quality control layer 107b has a function y=L*lnx / e x +M curve distribution; the saturated electron drift velocity distribution of the first beam quality control layer 107a has a function y=N*e x / lnx+P curve distribution, the saturated electron drift rate distribution of the second beam quality control layer 107b has a function y=Q*lnx / e x +R curve distribution.

[0058] Preferably, the refractive index distribution, breakdown field intensity distribution, radiation recombination coefficient distribution, and saturated electron drift velocity distribution of the first beam quality control layer 107a have the following relationship: K≤B≤F≤P; the refractive index distribution, breakdown field intensity distribution, radiation recombination coefficient distribution, and saturated electron drift velocity distribution of the second beam quality control layer 107b have the following relationship: M≤D≤H≤R.

[0059] Preferably, the beam quality control layer 107 is any one or any combination of InGaN, InN, AlInGaN, GaN, AlGaN, InGaN / GaN superlattice, InGaN / AlInN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, GaN / AlInN superlattice, GaN / AlGaN superlattice, InGaN / InGaN superlattice, AlInGaN / AlInGaN superlattice or any combination with GaN;

[0060] The active layer 103 is a periodic structure composed of a well layer and a barrier layer, the period number is 3≥m≥1, the well layer is InGaN, and its thickness is 10 angstroms; the barrier layer is GaN, and its thickness is 10 angstroms;

[0061] The lower confinement layer 101 is a composite structure of AlGaN and InGaN, the lower waveguide layer 102 is a composite structure of GaN and InGaN, the upper waveguide layer 104 is InGaN, and the upper confinement layer 106 is a composite structure of AlGaN and GaN; the substrate 100 is a single crystal substrate, which is a GaN single crystal substrate.

[0062] Embodiment 2:

[0063] The difference between this embodiment and the first embodiment is that:

[0064] The Al element concentration of the first lower limiting layer 101a and the third lower limiting layer 101c gradually changes at an angle of 30° toward the substrate 100; the peak position of the In element concentration of the second lower limiting layer 101b suddenly changes at an angle of 60° toward the substrate 100; the peak position of the In element concentration of the first beam quality control layer 107a suddenly changes down at an angle of 90° toward the substrate 100, and the valley position of the Al element concentration suddenly changes up at an angle of 60° toward the substrate 100; the valley position of the In element concentration of the second beam quality control layer 107b suddenly changes up at an angle of 90° toward the substrate 100, and the peak position of the Al element concentration suddenly changes down at an angle of 60° toward the substrate 100;

[0065] The descending angle of the refractive index peak position of the first beam quality control layer 107a toward the substrate is a sudden descending angle, and the angle α is 90°; the rising angle of the refractive index valley position of the second beam quality control layer 107b toward the substrate is a sudden rising angle, and the angle β is 45°;

[0066] The refractive index peak position of the second lower confinement layer 101b decreases at a sudden drop angle toward the substrate, and the angle γ is 90°; the refractive index of the first lower confinement layer 101a decreases at a gradual drop angle toward the substrate, and the angle θ is 30°;

[0067] The refractive index of the third lower confinement layer 101 c changes gradually toward the substrate, and the angle φ is 30°.

[0068] The falling angle of the breakdown field intensity peak position of the first beam quality control layer 107a toward the substrate 100 is a sudden falling angle, and the angle ω is 90°; the rising angle of the breakdown field intensity valley position of the second beam quality control layer 107b toward the substrate 100 is a sudden rising angle, and the angle δ is 45°;

[0069] The peak position of the breakdown field strength of the second lower confinement layer 101b decreases at a sudden decrease angle toward the substrate 100, and the angle ψ is 90°; the breakdown field strength of the first lower confinement layer 101a decreases at a gradual change angle toward the substrate 100, and the angle ε is 30°; the breakdown field strength of the third lower confinement layer 101c decreases at a gradual change angle toward the substrate 100, and the angle σ is 30°;

[0070] The rising angle of the valley position of the polarized optical phonon energy of the first beam quality control layer 107a toward the substrate 100 is a sudden rising angle, and the angle μ is 90°; the falling angle of the peak position of the polarized optical phonon energy of the second beam quality control layer 107b toward the substrate 100 is a sudden falling angle, and the angle ρ is 45°;

[0071] The rising angle of the valley position of the polarization optical phonon energy of the second lower confinement layer 101b toward the substrate 100 is a sudden rising angle, and the angle τ is 45°; the polarization optical phonon energy of the first lower confinement layer 101a is a gradual changing angle toward the substrate 100, and the angle υ is 30°; the polarization optical phonon energy of the third lower confinement layer 101c is a gradual changing angle toward the substrate 100, and the angle χ is 30°;

[0072] The rising angle of the valley position of the longitudinal sound velocity of the first beam quality control layer 107a toward the substrate 100 is a sudden rising angle, and the angle κ is 90°; the falling angle of the peak position of the longitudinal sound velocity of the second beam quality control layer 107b toward the substrate 100 is a sudden falling angle, and the angle ζ is 45°;

[0073] The rising angle of the valley position of the longitudinal sound velocity of the second lower limiting layer 101b towards the substrate 100 is a sudden rising angle, and the angle π is 90°; the longitudinal sound velocity of the first lower limiting layer 101a is a gradual angle towards the substrate 100, and the angle ν is 30°; the longitudinal sound velocity of the third lower limiting layer 101c is a gradual angle towards the substrate 100, and the angle ξ is 30°;

[0074] The active layer 103 is a periodic structure composed of a well layer and a barrier layer. The thickness of the well layer is 150 angstroms; the thickness of the barrier layer is 200 angstroms.

[0075] The following table is a lateral comparison table of the conventional laser and the laser of the present invention:

[0076] The optical catastrophe ratio of traditional lasers is 22PPM, while the optical catastrophe ratio of the laser of the present invention is 7PPM, which is 68% lower than that of traditional lasers; the local limitation factor of the light field of traditional lasers is 1.73%, while the local limitation factor of the light field of the laser of the present invention is 2.43%, which is 40% higher than that of traditional lasers; the beam quality factor of traditional lasers is 1.87, while the beam quality factor of the laser of the present invention is 1.12, which is 67% higher than that of traditional lasers.

[0077] project Conventional laser Laser of the present invention Range of change Optical catastrophe ratio (PPM) 22 7 -68％ Light field local limitation factor 1.73％ 2.43％ 40％ <![CDATA[Beam quality factor M 2 > 1.87 1.12 67％ Focus spot resolution (nm) >200 <30

[0078] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A nitride semiconductor laser with a beam quality control layer, 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), an electron blocking layer (105) and an upper confinement layer (106), characterized in that: 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 first lower confinement layer (101a) and the third lower confinement layer (101c) are any one or any combination of AlGaN, GaN, AlInGaN and AlInN; the second lower confinement layer (101b) is any one or any combination of InGaN, AlInGaN and AlInN; a first beam quality control layer (107a) is provided between the first lower confinement layer (101a) and the second lower confinement layer (101b); a second beam quality control layer (107b) is provided between the second lower confinement layer (101b) and the third lower confinement layer (101c); the first beam quality control layer (107a) and the second beam quality control layer (107b) constitute a beam quality control layer (107).

2. The nitride semiconductor laser with a beam quality control layer according to claim 1, characterized in that: The Al element concentration of the first lower limiting layer (101a) and the third lower limiting layer (101c) presents a gradual change trend toward the substrate (100), and the gradual change angle is 0 to 30 degrees; the peak position of the In element concentration of the second lower limiting layer (101b) presents a sudden change trend toward the substrate (100), and the sudden change angle is 15 to 60 degrees; the peak position of the In element concentration of the first beam quality control layer (107a) presents a sudden downward trend toward the substrate (100), and the sudden downward angle is 4 5 to 90°, the valley value position of the Al element concentration presents a sudden upward trend towards the substrate (100), and the sudden upward angle is 30 to 60°; the valley value position of the In element concentration of the second beam quality control layer (107b) presents a sudden upward trend towards the substrate (100), and the sudden upward angle is 45 to 90°, and the peak value position of the Al element concentration presents a sudden downward trend towards the substrate (100), and the sudden downward angle is 30 to 60°; the angle is the tangent inclination angle along the curve; The gradually changing angle of the Al element concentration of the first lower limiting layer (101a) is ≤ the gradually changing angle of the Al element concentration of the third lower limiting layer (101c) ≤ the suddenly decreasing angle of the In element concentration of the second lower limiting layer (101b) ≤ the suddenly decreasing angle of the Al element concentration of the second beam quality control layer (107b) ≤ the suddenly increasing angle of the Al element concentration of the first beam quality control layer (107a) ≤ the suddenly increasing angle of the In element concentration of the second beam quality control layer (107b) ≤ the suddenly decreasing angle of the In element concentration of the first beam quality control layer (107a).

3. The nitride semiconductor laser with a beam quality control layer according to claim 1, characterized in that: The descending angle of the refractive index peak position of the first beam quality control layer (107a) toward the substrate is a sudden descending angle, the angle is α, wherein: 45°≤α≤90°; the rising angle of the refractive index valley position of the second beam quality control layer (107b) toward the substrate is a sudden rising angle, the angle is β, wherein: 0°≤β≤45°; The refractive index peak position of the second lower limiting layer (101b) decreases at a sudden decreasing angle toward the substrate, the angle being γ, wherein: 45°≤γ≤90°; the refractive index of the first lower limiting layer (101a) decreases at a gradual decreasing angle toward the substrate, the angle being θ, wherein: 0°≤θ≤30°; The refractive index of the third lower limiting layer (101c) changes gradually toward the substrate at an angle of φ, wherein: 0°≤φ≤30°; the gradually changing angle of the refractive index of the third lower limiting layer (101c) is ≤ the gradually changing angle of the refractive index of the first lower limiting layer (101a) ≤ the suddenly decreasing angle of the refractive index of the second lower limiting layer (101b) ≤ the suddenly increasing angle of the refractive index of the second beam quality control layer (107b) ≤ the suddenly decreasing angle of the refractive index of the first beam quality control layer (107a).

4. The nitride semiconductor laser with a beam quality control layer according to claim 1, characterized in that: The falling angle of the peak position of the breakdown field intensity of the first beam quality control layer (107a) toward the substrate (100) is a sudden falling angle, the angle is ω, wherein: 45°≤ω≤90°; the rising angle of the valley position of the breakdown field intensity of the second beam quality control layer (107b) toward the substrate (100) is a sudden rising angle, the angle is δ, wherein: 0°≤δ≤45°; The peak position of the breakdown field strength of the second lower confinement layer (101b) decreases at a sudden decrease angle toward the substrate (100), the angle being ψ, wherein: 45°≤ψ≤90°; the breakdown field strength of the first lower confinement layer (101a) decreases at a gradual change angle toward the substrate (100), the angle being ε, wherein: 0°≤ε≤30°; the breakdown field strength of the third lower confinement layer (101c) decreases at a gradual change angle toward the substrate (100), the angle being σ, wherein: 0°≤σ≤30°; The gradual change angle of the breakdown field intensity of the third lower confinement layer (101c) is ≤ the gradual change angle of the breakdown field intensity of the first lower confinement layer (101a) ≤ the sudden drop angle of the breakdown field intensity of the second lower confinement layer (101b) ≤ the sudden rise angle of the breakdown field intensity of the second beam quality control layer (107b) ≤ the sudden drop angle of the breakdown field intensity of the first beam quality control layer (107a).

5. The nitride semiconductor laser with a beam quality control layer according to claim 1, characterized in that: The rising angle of the valley position of the polarized optical phonon energy of the first beam quality control layer (107a) toward the substrate (100) is a sudden rising angle, and the angle is μ, wherein: 45°≤μ≤90°; the falling angle of the peak position of the polarized optical phonon energy of the second beam quality control layer (107b) toward the substrate (100) is a sudden falling angle, and the angle is ρ, wherein: 0°≤ρ≤45°; The rising angle of the valley position of the polarization optical phonon energy of the second lower confinement layer (101b) toward the substrate (100) is a sudden rising angle, the angle is τ, wherein: 45°≤τ≤90°; the polarization optical phonon energy of the first lower confinement layer (101a) is a gradual changing angle toward the substrate (100), the angle is υ, wherein: 0°≤υ≤30°; the polarization optical phonon energy of the third lower confinement layer (101c) is a gradual changing angle toward the substrate (100), the angle is χ, wherein: 0°≤χ≤30°; The slowly changing angle of polarization phonon energy of the third lower confinement layer (101c) is ≤ the slowly changing angle of polarization phonon energy of the first lower confinement layer (101a) ≤ the suddenly rising angle of polarization phonon energy of the second lower confinement layer (101b) ≤ the suddenly falling angle of polarization phonon energy of the second beam quality control layer (107b) ≤ the suddenly rising angle of polarization phonon energy of the first beam quality control layer (107a).

6. The nitride semiconductor laser with a beam quality control layer according to claim 1, characterized in that: The rising angle of the valley position of the longitudinal sound velocity of the first beam quality control layer (107a) toward the substrate (100) is a sudden rising angle, the angle being κ, wherein: 45°≤κ≤90°; the falling angle of the peak position of the longitudinal sound velocity of the second beam quality control layer (107b) toward the substrate (100) is a sudden falling angle, the angle being ζ, wherein: 0°≤ζ≤45°; The rising angle of the valley position of the longitudinal sound velocity of the second lower limiting layer (101b) toward the substrate (100) is a sudden rising angle, the angle is π, wherein: 45°≤π≤90°; the longitudinal sound velocity of the first lower limiting layer (101a) toward the substrate (100) is a gradual changing angle, the angle is ν, wherein: 0°≤ν≤30°; the longitudinal sound velocity of the third lower limiting layer (101c) toward the substrate (100) is a gradual changing angle, the angle is ξ, wherein: 0°≤ξ≤30°; The slow change angle of the longitudinal sound velocity of the third lower restriction layer (101c) is ≤ the slow change angle of the longitudinal sound velocity of the first lower restriction layer (101a) ≤ the sudden rise angle of the longitudinal sound velocity of the second lower restriction layer (101b) ≤ the sudden drop angle of the longitudinal sound velocity of the second beam quality control layer (107b) ≤ the sudden rise angle of the longitudinal sound velocity of the first beam quality control layer (107a).

7. The nitride semiconductor laser with a beam quality control layer according to claim 1, characterized in that: The sudden decrease angle of the refractive index change, the sudden decrease angle of the breakdown field intensity, the sudden increase angle of the polarization optical phonon energy, and the sudden increase angle of the longitudinal sound velocity of the first beam quality control layer (107a) have the following relationship: 45°≤μ≤κ≤α≤ω≤90°; the sudden increase angle of the refractive index change, the sudden increase angle of the breakdown field intensity, the sudden decrease angle of the polarization optical phonon energy, and the sudden decrease angle of the longitudinal sound velocity of the second beam quality control layer (107b) have the following relationship: 45°≤ρ≤ζ≤β≤δ≤90°.

8. The nitride semiconductor laser with a beam quality control layer according to claim 1, characterized in that: The refractive index distribution of the first beam quality control layer (107a) has a function y=A*e x / lnx+B curve distribution, the refractive index distribution of the second beam quality control layer (107b) has a function y=C*lnx / e x +D curve distribution; the breakdown field intensity distribution of the first beam quality control layer (107a) has a function y=E*e x / lnx+F curve distribution, the breakdown field intensity distribution of the second beam quality control layer (107b) has a function y=G*lnx / e x +H curve distribution; The radiation recombination coefficient distribution of the first beam quality control layer (107a) has a function y=J*e x / lnx+K curve distribution, the radiation recombination coefficient distribution of the second beam quality control layer (107b) has a function y=L*lnx / e x +M curve distribution; the saturated electron drift velocity distribution of the first beam quality control layer (107a) has a function y=N*e x / lnx+P curve distribution, the saturated electron drift rate distribution of the second beam quality control layer (107b) has a function y=Q*lnx / e x +R curve distribution.

9. The nitride semiconductor laser with a beam quality control layer according to claim 8, characterized in that: The refractive index distribution, breakdown field intensity distribution, radiation recombination coefficient distribution, and saturated electron drift rate distribution of the first beam quality control layer (107a) have the following relationship: K≤B≤F≤P; the refractive index distribution, breakdown field intensity distribution, radiation recombination coefficient distribution, and saturated electron drift rate distribution of the second beam quality control layer (107b) have the following relationship: M≤D≤H≤R.

10. The nitride semiconductor laser with a beam quality control layer according to claim 1, characterized in that: The beam quality control layer (107) is any one or any combination of InGaN, InN, AlInGaN, GaN, AlGaN, InGaN / GaN superlattice, InGaN / AlInN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, GaN / AlInN superlattice, GaN / AlGaN superlattice, InGaN / InGaN superlattice, AlInGaN / AlInGaN superlattice or any combination with GaN; The active layer (103) is a periodic structure composed of a well layer and a barrier layer, the number of periods is 3≥m≥1, and the well layer is any one or any 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, diamond The barrier layer is any one or any combination 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, and its thickness is 10 to 200 angstroms; The lower confinement layer (101), the lower waveguide layer (102), the upper waveguide layer (104), and the upper confinement layer (106) are 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, Si C, Ga2O3, BN, diamond, any one or any combination thereof; the substrate (100) is a single crystal substrate, which is any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, sapphire / SiNx, sapphire / SiO2 / SiNx composite substrate, sapphire / SiNx / SiO2 composite substrate, magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

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