GaN-based semiconductor laser chip with kink-inhibiting upper waveguide layer

Abstract

The invention provides a GaN-based semiconductor laser chip with a kink-inhibiting upper waveguide layer. The GaN-based semiconductor laser chip comprises a substrate, a lower coating layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper coating layer which are sequentially arranged from bottom to top. By designing the refractive index coefficient of the upper waveguide layer, the descending angle of the peak position of hole mobility in the direction of the upper coating layer and the ascending angle of the valley position in the direction of the active layer, the carrier limiting effect of the upper waveguide layer is enhanced, the leakage of electrons to one side of the upper waveguide layer is reduced, the permeation and expansion of carriers to a passive region are inhibited, and the performance of the device is improved. The radiation mode shape distortion is inhibited, the radiation recombination loss is reduced, the radiation recombination efficiency and the external differential component efficiency of a fundamental mode are improved, the threshold current density and the kink critical current are reduced, and the slope efficiency and the optical power of the laser are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor optoelectronic devices, and in particular to a GaN-based semiconductor laser chip with a kink-suppressing upper waveguide 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 the classification methods are also diverse, mainly including 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.

[0003] There are big differences between lasers and nitride semiconductor light-emitting diodes:

[0004] 1) Laser is generated by stimulated radiation of carriers, the spectrum half-width is small, the brightness is very high, and the output power of a single laser can be in the W level, while nitride semiconductor light-emitting diodes are spontaneously radiated, and the output power of a single light-emitting diode is in the mW level;

[0005] 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;

[0006] 3) The spontaneous transition radiation of the light-emitting diode is incoherent light that transitions from a high energy level to a low energy level without any external influence, while the laser is stimulated transition radiation, and the energy of the induced photon should be equal to the difference in the energy level of the electron transition, producing the same coherent light as the photon and the induced photon;

[0007] 4) Different principles: When an external voltage is applied to a light-emitting diode, electron holes jump to a quantum well or a pn junction to generate radiative recombination light, while a laser can only emit when the lasing conditions are met. The carrier distribution in the active region must be reversed, and the stimulated radiation light oscillates back and forth in the resonant cavity. The propagation in the gain medium amplifies the light, and the threshold condition is met so that the gain is greater than the loss, and finally the laser is output.

[0008] Nitride semiconductor lasers have the following problems: high defect density, high impurity concentration, high stress and other crystal quality problems, which restrict the improvement of laser performance and reliability; material inhomogeneity or structural inhomogeneity causes minority carrier disturbance in the active region, and the lateral distribution shape concentrated on the base side mode reduces the carrier concentration in the center of the active region, causing the local gain distribution to flatten, weakening the junction plane waveguide effect and changing the mode distribution, enhancing the penetration and diffusion of carriers into the passive region, and ultimately leading to increased radiation loss, reduced base mode gain, and kinking of emission characteristics. At the same time, the optical mode moves relative to the center along the junction plane, and the radiation self-focusing effect also causes kinking of the PI curve. As the current increases, the imaginary and real parts of the refractive index change, causing the shape of the radiation mode spectrum to be distorted, the external differential quantum efficiency of the base side mode decreases, and the emission characteristics begin to bend, causing the kink critical current to decrease. Summary of the invention

[0009] To solve one of the above technical problems, the present invention provides a GaN-based semiconductor laser chip having a kink-suppressed upper waveguide layer.

[0010] The embodiment of the present invention provides a GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer, comprising a substrate, a lower cladding layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper cladding layer arranged in sequence from bottom to top, wherein the upper waveguide layer has a refractive index coefficient distribution characteristic and a hole mobility distribution characteristic;

[0011] The descending angle of the peak position of the refractive index coefficient of the upper waveguide layer toward the upper cladding layer is α, and the rising angle of the valley position of the refractive index coefficient of the upper waveguide layer toward the active layer is β, wherein: 25°≤α≤β≤90°;

[0012] The peak position of the hole mobility of the upper waveguide layer has a descending angle σ toward the upper cladding layer, and the valley position of the hole mobility of the upper waveguide layer has a rising angle υ toward the active layer, wherein 15°≤σ≤υ≤90°.

[0013] Preferably, the refractive index of the upper waveguide layer has a function y 1 =A+B*(a x +1) / (a x -1) curve distribution, where 0<a<1, x is the depth of the upper waveguide layer toward the electron blocking layer.

[0014] Preferably, the hole mobility of the upper waveguide layer has a function y 2 =J+K*lnx+x curve distribution.

[0015] Preferably, the upper waveguide layer also has deformation potential distribution characteristics, separation energy distribution characteristics and transverse sound velocity distribution characteristics;

[0016] The rising angle of the valley position of the deformation potential of the upper waveguide layer toward the upper cladding layer is γ, the rising angle of the valley position of the separation energy of the upper waveguide layer toward the upper cladding layer is θ, and the rising angle of the valley position of the transverse sound velocity of the upper waveguide layer toward the upper cladding layer is δ, wherein: 15°≤δ≤γ≤θ≤σ≤90°;

[0017] The peak position of the deformation potential of the upper waveguide layer decreases at an angle toward the active layer of The descending angle of the peak position of the separation energy of the upper waveguide layer toward the active layer is ψ, and the descending angle of the peak position of the transverse sound velocity of the upper waveguide layer toward the active layer is μ, wherein:

[0018] Preferably, the relationship between the deformation potential, separation energy, rising angle of the valley position of the transverse sound velocity toward the upper cladding layer and the descending angle of the peak position toward the active layer of the upper waveguide layer, the refractive index coefficient of the upper waveguide layer, the descending angle of the peak position of the hole mobility toward the upper cladding layer and the rising angle of the valley position toward the active layer is:

[0019] Preferably, the deformation potential of the upper waveguide layer has a function y 3 =C+D*(b x +1) / (b x -1) curve distribution, where b>1.

[0020] Preferably, the separation energy of the upper waveguide layer has a function y 4 =E+F*(c x +1) / (c x -1) Curve distribution, where c>1, A≤C≤E.

[0021] Preferably, the transverse acoustic velocity of the upper waveguide layer has a function y 5 =G+H*cosx / xThe first four-quadrant curve distribution, where J≤G.

[0022] Preferably, the upper waveguide layer is any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, and has a thickness of 10 nm to 1000 nm.

[0023] Preferably, the active layer is a periodic structure composed of a well layer and a barrier layer, and the well layer of the active layer is 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, Ga 2 O 3 , BN, diamond, any one or any combination thereof, with a thickness of 10 angstroms to 100 angstroms, and the barrier layer of the active layer is 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, Ga 2 O 3 , BN, diamond or any combination thereof, with a thickness of 10 angstroms to 200 angstroms.

[0024] Preferably, the lower cladding layer, the lower waveguide layer, the electron blocking layer, and the upper cladding 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, Ga 2 O 3 , BN, diamond or any combination thereof.

[0025] Preferably, the substrate comprises sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO 2 Composite substrates, Mo, TiW, CuW, Cu, sapphire / AlN composite substrates, diamond, graphene, sapphire / SiN x , Sapphire / SiO 2 / SiN x Composite substrate, sapphire / SiNx / SiO 2 Composite substrate, magnesium aluminum spinel MgAl 2 O 4 、MgO、ZnO、ZrB 2 、LiAlO 2 and LiGaO 2 Any type of composite substrate.

[0026] The beneficial effects of the present invention are as follows: the GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer proposed by the present invention enhances the carrier confinement effect of the upper waveguide layer by designing the refractive index coefficient of the upper waveguide layer, the descending angle of the peak position of the hole mobility toward the upper cladding layer, and the rising angle of the valley position toward the active layer, reduces the leakage of electrons toward one side of the upper waveguide layer, suppresses the penetration and expansion of carriers into the passive region, suppresses the distortion of the radiation mode shape, reduces the radiation recombination loss, improves the radiation recombination efficiency and the external differential quantum efficiency of the fundamental mode, reduces the threshold current density and the kink critical current, and improves the slope efficiency and optical power of the laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0028] Figure 1 A schematic diagram of the structure of a GaN-based semiconductor laser chip with a kink-suppressing upper waveguide layer according to an embodiment of the present invention;

[0029] Figure 2 This is a structural SIMS secondary ion mass spectrum of a GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to an embodiment of the present invention;

[0030] Figure 3 It is a partial enlarged view of the SIMS secondary ion mass spectrum of the structure of the GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to an embodiment of the present invention;

[0031] Figure 4 This is a TEM lens electron microscope image of a GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to an embodiment of the present invention;

[0032] Figure 5 This is a TEM lens electron microscope image of the upper cladding layer of the GaN-based semiconductor laser chip with a kink-suppressing upper waveguide layer according to an embodiment of the present invention;

[0033] Figure 6This is a TEM lens electron microscope image of the active layer of the GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to an embodiment of the present invention;

[0034] Figure 7 This is a TEM lens electron microscope image of the lower cladding layer of the GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to an embodiment of the present invention;

[0035] Figure 8 This is a TEM lens electron microscope image of the lower cladding layer and substrate of the GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to an embodiment of the present invention.

[0036] Reference numerals:

[0037] 100. substrate, 101. lower cladding layer, 102. lower waveguide layer, 103. active layer, 104. upper waveguide layer, 105. electron blocking layer, 106. upper cladding layer. DETAILED DESCRIPTION

[0038] In order to make the technical solutions and advantages in the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0039] like Figures 1 to 8 As shown, this embodiment provides a GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer, including a substrate 100, a lower cladding layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, an electron blocking layer 105 and an upper cladding layer 106 arranged in sequence from bottom to top.

[0040] Specifically, in this embodiment, the GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer is provided with a substrate 100, a lower cladding layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, an electron blocking layer 105, and an upper cladding layer 106 in order from bottom to top. The upper waveguide layer 104 has a refractive index distribution characteristic and a hole mobility distribution characteristic, so that the upper waveguide layer 104 becomes a kink-suppressed upper waveguide layer.

[0041] More specifically, in this embodiment, the refractive index coefficient and the hole mobility in the upper waveguide layer 104 have a certain change trend in the direction of the upper cladding layer 106 and the direction of the active layer 103, which is specifically manifested as follows:

[0042] The variation trend of the refractive index coefficient toward the upper cladding layer 106 and the active layer 103 is:

[0043] The peak position of the refractive index coefficient of the upper waveguide layer 104 shows a decreasing trend toward the upper cladding layer 106;

[0044] The valley position of the refractive index coefficient of the upper waveguide layer 104 shows an upward trend toward the active layer 103;

[0045] Furthermore, the descending angle of the peak position of the refractive index coefficient of the upper waveguide layer 104 toward the upper cladding layer 106 is α, and the rising angle of the valley position of the refractive index coefficient of the upper waveguide layer 104 toward the active layer 103 is β, wherein: 25°≤α≤β≤90°.

[0046] The variation trend of hole mobility toward the upper cladding layer 106 and the active layer 103 is:

[0047] The peak position of the hole mobility of the upper waveguide layer 104 shows a decreasing trend toward the upper cladding layer 106;

[0048] The valley position of the hole mobility of the upper waveguide layer 104 shows an upward trend toward the active layer 103;

[0049] Furthermore, the peak position of the hole mobility of the upper waveguide layer 104 has a decreasing angle σ toward the upper cladding layer 106 , and the valley position of the hole mobility of the upper waveguide layer 104 has a rising angle υ toward the active layer 103 , wherein 15°≤σ≤υ≤90°.

[0050] In this embodiment, by designing the refractive index coefficient of the upper waveguide layer 104, the descending angle of the peak position of the hole mobility toward the upper cladding layer 106, and the rising angle of the valley position toward the active layer 103, the carrier confinement effect of the upper waveguide layer 104 is enhanced, the leakage of electrons toward one side of the upper waveguide layer 104 is reduced, the penetration and expansion of carriers into the passive region is suppressed, the shape distortion of the radiation mode is suppressed, the radiation recombination loss is reduced, the radiation recombination efficiency and the external differential quantum efficiency of the fundamental mode are improved, the threshold current density and the kink critical current are reduced, and the slope efficiency and optical power of the laser are improved.

[0051] In some optional embodiments, the refractive index of the upper waveguide layer 104 has a function y 1 =A+B*(a x +1) / (a x -1) curve distribution, wherein 0<a<1, and x is the depth from the upper waveguide layer 104 to the electron blocking layer 105.

[0052] In some optional embodiments, the hole mobility of the upper waveguide layer 104 has a function y 2 =J+K*lnx+x curve distribution.

[0053] In some optional embodiments, the upper waveguide layer 104 also has deformation potential distribution characteristics, separation energy distribution characteristics and transverse sound velocity distribution characteristics, and the deformation potential, separation energy and transverse sound velocity in the upper waveguide layer 104 also have certain change trends in the direction of the upper cladding layer 106 and the direction of the active layer 103, which are specifically manifested as follows:

[0054] The variation trend of the deformation potential toward the upper cladding layer 106 and the active layer 103 is:

[0055] The valley position of the deformation potential of the upper waveguide layer 104 shows an upward trend toward the upper cladding layer 106;

[0056] The peak position of the deformation potential of the upper waveguide layer 104 shows a downward trend toward the active layer 103 .

[0057] The variation trend of the separation energy toward the upper cladding layer 106 and the active layer 103 is:

[0058] The valley position of the separation energy of the upper waveguide layer 104 shows an upward trend toward the upper cladding layer 106;

[0059] The peak position of the separation energy of the upper waveguide layer 104 shows a downward trend toward the active layer 103 .

[0060] The variation trend of the transverse sound velocity toward the cladding layer 106 and the active layer 103 is:

[0061] The valley position of the transverse acoustic velocity of the upper waveguide layer 104 shows an upward trend toward the upper cladding layer 106;

[0062] The peak position of the transverse acoustic velocity of the upper waveguide layer 104 shows a downward trend toward the active layer 103 .

[0063] Furthermore, the rising angle of the valley position of the deformation potential of the upper waveguide layer 104 toward the upper cladding layer 106 is γ, the rising angle of the valley position of the separation energy of the upper waveguide layer 104 toward the upper cladding layer 106 is θ, and the rising angle of the valley position of the transverse sound velocity of the upper waveguide layer 104 toward the upper cladding layer 106 is δ, wherein: 15°≤δ≤γ≤θ≤σ≤90°.

[0064] The peak position of the deformation potential of the upper waveguide layer 104 decreases at an angle toward the active layer 103. The descending angle of the peak position of the separation energy of the upper waveguide layer 104 toward the active layer 103 is ψ, and the descending angle of the peak position of the transverse sound velocity of the upper waveguide layer 104 toward the active layer 103 is μ, where:

[0065] Furthermore, the relationship between the deformation potential, separation energy, rising angle of the valley position of the transverse sound velocity toward the upper cladding layer 106 and the descending angle of the peak position toward the active layer 103 of the upper waveguide layer 104, the descending angle of the peak position of the hole mobility toward the upper cladding layer 106 and the rising angle of the valley position toward the active layer 103 is as follows:

[0066] This embodiment controls the rising angle of the valley position of the deformation potential, separation energy, and transverse sound velocity of the upper waveguide layer 104 toward the upper cladding layer 106, and the descending angle of the peak position toward the active layer 103, thereby suppressing the spontaneous polarization and strain inhomogeneity, suppressing the change of the laser in the propagation direction in the high-order transverse mode, suppressing the transition of the radiation mode from the fundamental mode to the high-order mode, and suppressing the kink of the PI curve. At the same time, the uniformity of the point defects of the waveguide layer is reduced, the uniformity of the crystal quality and structure of the waveguide layer is improved, the disturbance of the minority carriers injected into the active region is reduced, the change from the TE mode to the TM mode is suppressed, the relative movement of the optical mode along the junction plane and the radiation self-focusing effect are suppressed, and the discontinuity of the laser PI curve and the internal light absorption loss are suppressed.

[0067] In some optional embodiments, the deformation potential of the upper waveguide layer 104 has a function y 3 =C+D*(b x +1) / (b x -1) curve distribution, where b>1.

[0068] In some optional embodiments, the separation energy of the upper waveguide layer 104 has a function y 4 =E+F*(c x +1) / (c x -1) Curve distribution, where c>1, A≤C≤E.

[0069] In some optional embodiments, the transverse acoustic velocity of the upper waveguide layer 104 has a function y 5 =G+H*cosx / xThe first four-quadrant curve distribution, where J≤G.

[0070] In some optional embodiments, the upper waveguide layer 104 is any one or any combination of InGaN, GaN, InN, AlInGaN, and AlInN, and has a thickness of 10 nm to 1000 nm.

[0071] In some optional embodiments, the active layer 103 is a periodic structure composed of a well layer and a barrier layer, and the number of periods is 1 to 5. In this embodiment, the period of the active layer 103 is 2, including a first active layer 103a and a second active layer 103b.

[0072] Specifically, the well layer of the active layer 103 is GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, I nGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga 2 O 3 , BN, diamond or any combination thereof, with a thickness of 10 angstroms to 100 angstroms.

[0073] The barrier layer of the active layer 103 is GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InG aAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga 2 O 3 , BN, diamond or any combination thereof, with a thickness of 10 angstroms to 200 angstroms.

[0074] In some optional embodiments, the lower cladding layer 101, the lower waveguide layer 102, the electron blocking layer 105, and the upper cladding 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, SiC, Ga 2 O 3 , BN, diamond or any combination thereof.

[0075] In some optional embodiments, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO 2 Composite substrates, Mo, TiW, CuW, Cu, sapphire / AlN composite substrates, diamond, graphene, sapphire / SiN x , Sapphire / SiO2 / SiN x Composite substrate, sapphire / SiN x / SiO 2 Composite substrate, magnesium aluminum spinel MgAl 2 O 4 、MgO、ZnO、ZrB 2 、LiAlO 2 and LiGaO 2 Any type of composite substrate.

[0076] The following table is a parameter comparison between a conventional semiconductor laser element and a GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer proposed in this embodiment, including slope efficiency, threshold current density, optical power, internal optical loss, kink Kink critical current, and optical catastrophe ratio, showing the difference between a conventional semiconductor laser element and a GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer proposed in this embodiment:

[0077]

[0078] It can be seen that the GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer proposed in this embodiment has improved slope efficiency and optical power, reduced threshold current density, internal optical loss and optical catastrophe ratio, and significantly improved kink Kink critical current compared with traditional semiconductor laser elements. It has obvious advantages over traditional semiconductor laser elements.

[0079] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer, comprising a substrate, a lower cladding layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper cladding layer arranged in sequence from bottom to top, characterized in that: The upper waveguide layer has a refractive index distribution characteristic and a hole mobility distribution characteristic; The descending angle of the peak position of the refractive index coefficient of the upper waveguide layer toward the upper cladding layer is α, and the rising angle of the valley position of the refractive index coefficient of the upper waveguide layer toward the active layer is β, wherein: 25°≤α≤β≤90°; The peak position of the hole mobility of the upper waveguide layer has a descending angle σ toward the upper cladding layer, and the valley position of the hole mobility of the upper waveguide layer has a rising angle υ toward the active layer, wherein 15°≤σ≤υ≤90°.

2. The GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to claim 1, characterized in that: The refractive index of the upper waveguide layer has the function y1=A+B*(a x +1) / (a x -1) curve distribution, where 0<a<1, x is the depth of the upper waveguide layer toward the electron blocking layer.

3. The GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to claim 2, characterized in that: The hole mobility of the upper waveguide layer has a curve distribution of function y2=J+K*lnx+x.

4. The GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to claim 3, characterized in that: The upper waveguide layer also has deformation potential distribution characteristics, separation energy distribution characteristics and transverse sound velocity distribution characteristics; The rising angle of the valley position of the deformation potential of the upper waveguide layer toward the upper cladding layer is γ, the rising angle of the valley position of the separation energy of the upper waveguide layer toward the upper cladding layer is θ, and the rising angle of the valley position of the transverse sound velocity of the upper waveguide layer toward the upper cladding layer is δ, wherein: 15°≤δ≤γ≤θ≤σ≤90°; The peak position of the deformation potential of the upper waveguide layer decreases at an angle toward the active layer of The descending angle of the peak position of the separation energy of the upper waveguide layer toward the active layer is ψ, and the descending angle of the peak position of the transverse sound velocity of the upper waveguide layer toward the active layer is μ, wherein:

5. The GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to claim 4, characterized in that: The relationship between the deformation potential, separation energy, rising angle of the valley position of the transverse sound velocity toward the upper cladding layer and the descending angle of the peak position toward the active layer of the upper waveguide layer, the refractive index coefficient of the upper waveguide layer, the descending angle of the peak position of the hole mobility toward the upper cladding layer and the rising angle of the valley position toward the active layer is:

6. The GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to claim 4, characterized in that: The deformation potential of the upper waveguide layer has the function y3=C+D*(b x +1) / (b x -1) curve distribution, where b>1.

7. The GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to claim 6, characterized in that: The separation energy of the upper waveguide layer has the function y4=E+F*(c x +1) / (c x -1) Curve distribution, where c>1, A≤C≤E.

8. The GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to claim 4, characterized in that: The transverse acoustic velocity of the upper waveguide layer has a first four-quadrant curve distribution of function y5=G+H*cosx / x, wherein J≤G.

9. The GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to claim 1, characterized in that: The upper waveguide layer is any one or any combination of InGaN, GaN, InN, AlInGaN, and AlInN, and has a thickness of 10 nm to 1000 nm.

10. The GaN-based semiconductor laser chip with a kink-suppressed upper waveguide layer according to claim 1, characterized in that: The active layer is a periodic structure composed of a well layer and a barrier layer. The well layer of the active 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 has a thickness of 1 0 angstroms to 100 angstroms, the barrier layer of the active 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 the thickness is 10 angstroms to 200 angstroms; The lower cladding layer, the lower waveguide layer, the electron blocking layer, and the upper cladding layer are 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 substrate includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, graphene, sapphire / SiN x , Sapphire / SiO2 / SiN x Composite substrate, sapphire / SiN x Any one of a / SiO2 composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

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