GaN-based compound semiconductor laser element

Abstract

The GaN-based compound semiconductor laser element comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper limiting layer which are sequentially arranged from bottom to top, and an electron spin state regulation and control layer is arranged between the lower limiting layer and the lower waveguide layer. And designing piezoelectric polarization coefficient distribution of a first electron spin state regulation layer and a second electron spin state regulation layer in the electron spin state regulation layer, and a relation of piezoelectric polarization coefficients among the lower limiting layer, the lower waveguide layer, the first electron spin state regulation layer and the second electron spin state regulation layer. The performance of the semiconductor laser element can be improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor optoelectronic devices, and in particular to a GaN-based compound semiconductor laser element. 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:

[0009] 1) The large internal lattice mismatch and strain cause strong polarization effect, and the QCSE quantum confined Stark effect strongly limits the improvement of the laser lasing gain;

[0010] 2) The optical waveguide 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. A large amount of unionized Mg acceptor impurities will cause the internal optical loss to increase. In addition, the refractive index dispersion of the laser and the limiting factor decrease with the increase of wavelength, resulting in a decrease in the mode gain of the laser.

[0011] 3) Increasing the thickness of the lower confinement layer can reduce the refractive index of the confinement layer, but increasing the thickness of the lower confinement layer will limit the range of component regulation, and easily cause problems such as cracking, bending and quality degradation; at the same time, 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;

[0012] 4) The activation energy of the Mg acceptor of the p-type semiconductor is large, the ionization efficiency is low, the hole concentration is much lower than the electron concentration, and the hole mobility is much lower than the electron mobility, resulting in serious asymmetric mismatch between electrons and holes in the quantum well, electron leakage and carrier delocalization, more difficult hole transport in the quantum well, uneven carrier injection, uneven gain, broadening of the laser gain spectrum, and decreased peak gain;

[0013] 5) The step difference of the laser valence band increases, the hole transport in the quantum well becomes more difficult, the carrier injection is uneven, and the gain is uneven; after the laser is lased, the carrier concentration in the multi-quantum well active region is saturated, the bipolar conductivity effect is weakened, and the series resistance of the laser increases, resulting in an increase in the laser voltage. Summary of the invention

[0014] To solve one of the above technical problems, the present invention provides a GaN-based compound semiconductor laser element.

[0015] An embodiment of the present invention provides a GaN-based compound semiconductor laser element, comprising a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper confinement layer arranged in sequence from bottom to top, an electron spin state regulation layer is arranged between the lower confinement layer and the lower waveguide layer, the electron spin state regulation layer comprises a first electron spin state regulation layer and a second electron spin state regulation layer, the first electron spin state regulation layer is located below the second electron spin state regulation layer, the lower confinement layer, the lower waveguide layer, the first electron spin state regulation layer and the second electron spin state regulation layer all have a piezoelectric polarization coefficient distribution characteristic, and the piezoelectric polarization coefficient of the lower waveguide layer is ≥ the piezoelectric polarization coefficient of the second electron spin state regulation layer ≥ the piezoelectric polarization coefficient of the first electron spin state regulation layer ≥ the piezoelectric polarization coefficient of the lower confinement layer, and the piezoelectric polarization coefficient of the first electron spin state regulation layer has a function y1=A+Bx1 -a The curve distribution, and a is an odd number greater than 1, x1 is the depth of the first electron spin state control layer toward the second electron spin state control layer, and the piezoelectric polarization coefficient of the second electron spin state control layer has the function y2=bx22 +cx2+d curve distribution, and b<0, x2 is the depth of the second electron spin state control layer towards the lower waveguide layer.

[0016] Preferably, the lower confinement layer, the lower waveguide layer, the first electron spin state regulation layer and the second electron spin state regulation layer all have a spontaneous polarization coefficient distribution characteristic, and the spontaneous polarization coefficient of the lower waveguide layer is ≤ the spontaneous polarization coefficient of the second electron spin state regulation layer ≤ the spontaneous polarization coefficient of the first electron spin state regulation layer ≤ the spontaneous polarization coefficient of the lower confinement layer, and the spontaneous polarization coefficient of the first electron spin state regulation layer has the function y3=C+D*k x1 Curve distribution, and k>1, the spontaneous polarization coefficient of the second electron spin state control layer y4=hx2 2 +fx2+g curve distribution, and h>0.

[0017] Preferably, the lower confinement layer, the lower waveguide layer, the first electron spin state regulation layer and the second electron spin state regulation layer all have a thermal expansion coefficient distribution characteristic, and the thermal expansion coefficient of the lower waveguide layer ≤ the thermal expansion coefficient of the second electron spin state regulation layer ≤ the thermal expansion coefficient of the first electron spin state regulation layer ≤ the thermal expansion coefficient of the lower confinement layer, and the thermal expansion coefficient of the first electron spin state regulation layer has a function y5=E+F*x1e x1 Curve distribution, the thermal expansion coefficient of the second electron spin state regulation layer has a function y6 = G + e x2 +e -x2 Curved distribution.

[0018] Preferably, the lower confinement layer, the lower waveguide layer, the first electron spin state regulation layer and the second electron spin state regulation layer all have conduction band effective state density distribution characteristics, and the conduction band effective state density of the lower waveguide layer ≤ the conduction band effective state density of the second electron spin state regulation layer ≤ the conduction band effective state density of the first electron spin state regulation layer ≤ the conduction band effective state density of the lower confinement layer, and the conduction band effective state density distribution of the first electron spin state regulation layer has a function y7=H+J*x1 2 e x1 Curve distribution, the conduction band effective state density distribution of the second electron spin state regulation layer y8 = K + L * e x2 +M*x2 2 Curved distribution.

[0019] Preferably, in the spontaneous polarization coefficient distribution, piezoelectric polarization coefficient distribution, thermal expansion coefficient distribution, and conduction band effective state density distribution function of the first electron spin state regulation layer, C≤A≤E≤H;

[0020] In the spontaneous polarization coefficient distribution, piezoelectric polarization coefficient distribution, thermal expansion coefficient distribution, and conduction band effective state density distribution function of the first electron spin state regulation layer, g≤d≤G≤K.

[0021] Preferably, the first electron spin state control layer and the second electron spin state control layer are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInGaN superlattice, GaN / AlInGaN superlattice, GaN / AlN superlattice, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN.

[0022] Preferably, the thickness of the electron spin state regulation layer is 0.5 nm to 5000 nm.

[0023] Preferably, 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 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 combination, with a thickness of 10 angstroms to 100 angstroms, and 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, and BN, with a thickness of 10 angstroms to 150 angstroms.

[0024] Preferably, the lower limiting layer, the lower waveguide layer, the upper waveguide layer, and the upper limiting 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, and BN.

[0025] Preferably, the substrate comprises sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x , Sapphire / SiO2 / SiN x Any one of a composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

[0026] The beneficial effects of the present invention are as follows: the present invention sets an electron spin state regulation layer between the lower confinement layer and the lower waveguide layer of a GaN-based compound semiconductor laser element, designs the piezoelectric polarization coefficient distribution of the first electron spin state regulation layer and the second electron spin state regulation layer in the electron spin state regulation layer, and designs the relationship between the piezoelectric polarization coefficients of the lower confinement layer, the lower waveguide layer, the first electron spin state regulation layer, and the second electron spin state regulation layer. The electron spin state regulation layer allows electrons and ions to undergo spin flip relaxation through the spin conservation pathway, so that the carrier kinetic energy generates additional electron-hole pairs for relaxation, causing spin carrier multiplication, thereby increasing the exciton generation rate of the active layer, reducing the phonon-assisted relaxation rate, enhancing the Coulomb collision rate, enhancing the hole injection efficiency and the injection uniformity of carriers, accelerating the critical current of the laser population inversion, reducing the threshold current density, and suppressing the degree of electron spin polarization, thereby reducing the ratio of electrons and holes to produce opposite polarization states during the spin polarization process, enhancing the probability of electrons and holes having the same polarization spin direction, reducing the polarization effect and quantum-confined Stark effect of the active layer, and enhancing the probability of photogenerated carrier recombination. At the same time, it forms an inclined electron spin of interlayer electron hybridization, inducing ultra-long-life interlayer exciton transitions of direct momentum transitions, reducing bipolar conductivity, improving the carrier saturation problem after lasing, improving gain uniformity, reducing the excitation threshold of the laser element, enhancing the limiting factor and peak gain, and improving the optical power and slope efficiency of the laser element. 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 structural diagram of a GaN-based compound semiconductor laser element according to an embodiment of the present invention;

[0029] Figure 2 This is a SIMS secondary ion mass spectrum of the GaN-based compound semiconductor laser element described in an embodiment of the present invention.

[0030] Reference numerals:

[0031] 100, substrate, 101, lower confinement layer, 102, lower waveguide layer, 103, active layer, 104, upper waveguide layer, 105, upper confinement layer, 106, electron spin state control layer;

[0032] 106a, a first electron spin state regulating layer, 106b, a second electron spin state regulating layer. DETAILED DESCRIPTION

[0033] 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.

[0034] like Figure 1 and Figure 2 As shown, this embodiment proposes a GaN-based compound semiconductor laser element, including 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 arranged in sequence from bottom to top, and an electron spin state control layer 106 is also arranged in the GaN-based compound semiconductor laser element.

[0035] Specifically, in this embodiment, the GaN-based compound semiconductor laser element is provided with 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 in order from bottom to top. An electron spin state control layer 106 is also provided in the semiconductor laser element. The electron spin state control layer 106 is provided between the lower confinement layer 101 and the lower waveguide layer 102. The electron spin state control layer 106 is a double-layer structure, including a first electron spin state control layer 106a and a second electron spin state control layer 106b, wherein the first electron spin state control layer 106a is located below the second electron spin state control layer 106b.

[0036] In this embodiment, the lower confinement layer 101, the lower waveguide layer 102, the first electron spin state control layer 106a, and the second electron spin state control layer 106b all have piezoelectric polarization coefficient distribution characteristics, and the piezoelectric polarization coefficients in the lower confinement layer 101, the lower waveguide layer 102, the first electron spin state control layer 106a, and the second electron spin state control layer 106b have the following relationship:

[0037] The piezoelectric polarization coefficient of the lower waveguide layer 102 ≥ the piezoelectric polarization coefficient of the second electron spin state control layer 106 b ≥ the piezoelectric polarization coefficient of the first electron spin state control layer 106 a ≥ the piezoelectric polarization coefficient of the lower confinement layer 101 .

[0038] Furthermore, this embodiment also designs the distribution of piezoelectric polarization coefficients in the first electron spin state regulating layer 106a and the second electron spin state regulating layer 106b, which is specifically shown as follows:

[0039] The piezoelectric polarization coefficient of the first electron spin state control layer 106a has the function y1=A+Bx1 -a The curve distribution is as follows, and a is an odd number greater than 1, and x1 is the depth from the first electron spin state control layer 106a to the second electron spin state control layer 106b;

[0040] The piezoelectric polarization coefficient of the second electron spin state control layer 106b has the function y2=bx2 2 +cx2+d curve distribution, and b<0, x2 is the depth of the second electron spin state control layer 106b in the direction of the lower waveguide layer 102.

[0041] In this embodiment, an electron spin state control layer 106 is arranged between the lower confinement layer 101 and the lower waveguide layer 102 of the GaN-based compound semiconductor laser element, and the piezoelectric polarization coefficient distribution of the first electron spin state control layer 106a and the second electron spin state control layer 106b in the electron spin state control layer 106 is designed, as well as the relationship between the piezoelectric polarization coefficients among the lower confinement layer 101, the lower waveguide layer 102, the first electron spin state control layer 106a and the second electron spin state control layer 106b. The electron spin state control layer 106 allows electrons and ions to undergo spin flip relaxation through the spin conservation pathway, so that the carrier kinetic energy generates additional electron-hole pairs for relaxation, causing spin carrier multiplication, thereby increasing the exciton generation rate of the active layer 103, reducing the phonon-assisted relaxation rate, enhancing the Coulomb collision rate, enhancing the hole injection efficiency and the injection uniformity of carriers, accelerating the critical current of the laser's particle number inversion, reducing the threshold current density, and suppressing the degree of electron spin polarization, thereby reducing the generation of opposite polarization between electrons and holes during the spin polarization process. The ratio of states is increased, the probability of the same polarization spin direction of electrons and holes is enhanced, the polarization effect and quantum confined Stark effect of the active layer 103 are reduced, the probability of photogenerated carrier recombination is enhanced, and at the same time, the tilted electron spin of interlayer electron hybridization is formed, the ultra-long life interlayer exciton transition of inducing momentum direct transition is achieved, the bipolar conductivity is reduced, the carrier saturation problem after lasing is improved, the gain uniformity is improved, the excitation threshold of the laser element is reduced, the limitation factor and the peak gain are enhanced, and the optical power and slope efficiency of the laser element are improved.

[0042] In some optional embodiments, the lower confinement layer 101, the lower waveguide layer 102, the first electron spin state control layer 106a, and the second electron spin state control layer 106b also have a spontaneous polarization coefficient distribution characteristic, and the spontaneous polarization coefficients in the lower confinement layer 101, the lower waveguide layer 102, the first electron spin state control layer 106a, and the second electron spin state control layer 106b have the following relationship:

[0043] The spontaneous polarization coefficient of the lower waveguide layer 102 ≤ the spontaneous polarization coefficient of the second electron spin state control layer 106 b ≤ the spontaneous polarization coefficient of the first electron spin state control layer 106 a ≤ the spontaneous polarization coefficient of the lower confinement layer 101 .

[0044] Furthermore, this embodiment also designs the distribution of the spontaneous polarization coefficients in the first electron spin state regulation layer 106a and the second electron spin state regulation layer 106b, which is specifically shown as follows:

[0045] The spontaneous polarization coefficient of the first electron spin state control layer 106a has the function y3=C+D*k x1 Curve distribution, and k>1;

[0046] The spontaneous polarization coefficient of the second electron spin state control layer 106b is y4=hx2 2+fx2+g curve distribution, and h>0.

[0047] In some optional embodiments, the lower confinement layer 101, the lower waveguide layer 102, the first electron spin state control layer 106a, and the second electron spin state control layer 106b further have a thermal expansion coefficient distribution characteristic, and the thermal expansion coefficients in the lower confinement layer 101, the lower waveguide layer 102, the first electron spin state control layer 106a, and the second electron spin state control layer 106b have the following relationship:

[0048] The thermal expansion coefficient of the lower waveguide layer 102 ≤ the thermal expansion coefficient of the second electron spin state control layer 106 b ≤ the thermal expansion coefficient of the first electron spin state control layer 106 a ≤ the thermal expansion coefficient of the lower confinement layer 101 .

[0049] Furthermore, this embodiment also designs the distribution of thermal expansion coefficients in the first electron spin state regulation layer 106a and the second electron spin state regulation layer 106b, which is specifically shown as follows:

[0050] The thermal expansion coefficient of the first electron spin state control layer 106a has the function y5=E+F*x1e x1 Curve distribution;

[0051] The thermal expansion coefficient of the second electron spin state control layer 106b has the function y6=G+e x2 +e -x2 Curved distribution.

[0052] In some optional embodiments, the lower confinement layer 101, the lower waveguide layer 102, the first electron spin state control layer 106a, and the second electron spin state control layer 106b also have a conduction band effective state density distribution characteristic, and the conduction band effective state density in the lower confinement layer 101, the lower waveguide layer 102, the first electron spin state control layer 106a, and the second electron spin state control layer 106b has the following relationship:

[0053] The conduction band effective state density of the lower waveguide layer 102 ≤ the conduction band effective state density of the second electron spin state regulation layer 106 b ≤ the conduction band effective state density of the first electron spin state regulation layer 106 a ≤ the conduction band effective state density of the lower confinement layer 101 .

[0054] Furthermore, this embodiment also designs the effective state density distribution of the thermal conduction band in the first electron spin state regulation layer 106a and the second electron spin state regulation layer 106b, which is specifically shown as follows:

[0055] The conduction band effective state density distribution of the first electron spin state control layer 106a has the function y7=H+J*x1 2 e x1 Curve distribution;

[0056] The conduction band effective state density distribution y8 of the second electron spin state control layer 106b is y8=K+L*e x2 +M*x2 2 Curved distribution.

[0057] Among them, in the spontaneous polarization coefficient distribution, piezoelectric polarization coefficient distribution, thermal expansion coefficient distribution, and conduction band effective state density distribution function of the first electron spin state regulation layer 106a, C≤A≤E≤H. In the spontaneous polarization coefficient distribution, piezoelectric polarization coefficient distribution, thermal expansion coefficient distribution, and conduction band effective state density distribution function of the first electron spin state regulation layer 106a, g≤d≤G≤K.

[0058] In some optional embodiments, the first electron spin state control layer 106a and the second electron spin state control layer 106b are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInGaN superlattice, GaN / AlInGaN superlattice, GaN / AlN superlattice, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN.

[0059] In some optional embodiments, the thickness of the electron spin state control layer 106 is 0.5 nm to 5000 nm.

[0060] 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 3≥m≥1.

[0061] 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, and BN, and has a thickness of 10 to 100 angstroms.

[0062] 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, and BN, with a thickness of 10 to 150 angstroms.

[0063] In some optional embodiments, the lower confinement layer 101, the lower waveguide layer 102, the upper waveguide layer 104, and the upper confinement layer 105 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, and BN.

[0064] In some optional embodiments, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x , Sapphire / SiO2 / SiN x Any one of a composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

[0065] The following table is a parameter comparison between a conventional semiconductor laser element and the GaN-based compound semiconductor laser element proposed in this embodiment, including slope efficiency, threshold current density, optical power, and limiting factor to show the difference between the conventional semiconductor laser element and the GaN-based compound semiconductor laser element proposed in this embodiment:

[0066]

[0067]

[0068] It can be seen that the GaN-based compound semiconductor laser element proposed in this embodiment has improved slope efficiency, optical power and limitation factor, reduced threshold current density, and has obvious advantages over traditional semiconductor laser elements.

[0069] 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 compound semiconductor laser element, comprising a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper confinement layer arranged in sequence from bottom to top, characterized in that: An electron spin state regulation layer is arranged between the lower confinement layer and the lower waveguide layer, the electron spin state regulation layer includes a first electron spin state regulation layer and a second electron spin state regulation layer, the first electron spin state regulation layer is located below the second electron spin state regulation layer, the lower confinement layer, the lower waveguide layer, the first electron spin state regulation layer and the second electron spin state regulation layer all have piezoelectric polarization coefficient distribution characteristics, and the piezoelectric polarization coefficient of the lower waveguide layer ≥ the piezoelectric polarization coefficient of the second electron spin state regulation layer ≥ the piezoelectric polarization coefficient of the first electron spin state regulation layer ≥ the piezoelectric polarization coefficient of the lower confinement layer, and the piezoelectric polarization coefficient of the first electron spin state regulation layer has a function y1=A+Bx1 -a The curve distribution, and a is an odd number greater than 1, x1 is the depth of the first electron spin state control layer toward the second electron spin state control layer, and the piezoelectric polarization coefficient of the second electron spin state control layer has the function y2=bx2 2 +cx2+d curve distribution, and b<0, x2 is the depth of the second electron spin state control layer towards the lower waveguide layer.

2. The GaN-based compound semiconductor laser element according to claim 1, characterized in that: The lower confinement layer, the lower waveguide layer, the first electron spin state regulation layer and the second electron spin state regulation layer all have a spontaneous polarization coefficient distribution characteristic, and the spontaneous polarization coefficient of the lower waveguide layer is ≤ the spontaneous polarization coefficient of the second electron spin state regulation layer ≤ the spontaneous polarization coefficient of the first electron spin state regulation layer ≤ the spontaneous polarization coefficient of the lower confinement layer, and the spontaneous polarization coefficient of the first electron spin state regulation layer has the function y3=C+D*k x1 Curve distribution, and k>1, the spontaneous polarization coefficient of the second electron spin state control layer y4=hx2 2 +fx2+g curve distribution, and h>0.

3. The GaN-based compound semiconductor laser element according to claim 2, characterized in that: The lower confinement layer, the lower waveguide layer, the first electron spin state regulation layer and the second electron spin state regulation layer all have a thermal expansion coefficient distribution characteristic, and the thermal expansion coefficient of the lower waveguide layer is ≤ the thermal expansion coefficient of the second electron spin state regulation layer ≤ the thermal expansion coefficient of the first electron spin state regulation layer ≤ the thermal expansion coefficient of the lower confinement layer, and the thermal expansion coefficient of the first electron spin state regulation layer has a function y5=E+F*x1e x1 Curve distribution, the thermal expansion coefficient of the second electron spin state regulation layer has a function y6 = G + e x2 +e -x2 Curved distribution.

4. The GaN-based compound semiconductor laser element according to claim 3, characterized in that: The lower confinement layer, the lower waveguide layer, the first electron spin state regulation layer and the second electron spin state regulation layer all have conduction band effective state density distribution characteristics, and the conduction band effective state density of the lower waveguide layer ≤ the conduction band effective state density of the second electron spin state regulation layer ≤ the conduction band effective state density of the first electron spin state regulation layer ≤ the conduction band effective state density of the lower confinement layer, and the conduction band effective state density distribution of the first electron spin state regulation layer has a function y7=H+J*x1 2 e x1 Curve distribution, the conduction band effective state density distribution of the second electron spin state regulation layer y8 = K + L * e x2 +M*x2 2 Curved distribution.

5. The GaN-based compound semiconductor laser element according to claim 4, characterized in that: In the spontaneous polarization coefficient distribution, piezoelectric polarization coefficient distribution, thermal expansion coefficient distribution, and conduction band effective state density distribution function of the first electron spin state regulation layer, C≤A≤E≤H; In the spontaneous polarization coefficient distribution, piezoelectric polarization coefficient distribution, thermal expansion coefficient distribution, and conduction band effective state density distribution function of the first electron spin state regulation layer, g≤d≤G≤K.

6. The GaN-based compound semiconductor laser element according to claim 1, characterized in that: The first electron spin state control layer and the second electron spin state control layer are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInGaN superlattice, GaN / AlInGaN superlattice, GaN / AlN superlattice, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN.

7. The GaN-based compound semiconductor laser element according to claim 1, characterized in that: The thickness of the electron spin state regulation layer is 0.5 nm to 5000 nm.

8. The GaN-based compound semiconductor laser element according to claim 1, characterized in that: 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, and BN , with a thickness of 10 angstroms to 100 angstroms, and 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, and BN, with a thickness of 10 angstroms to 150 angstroms.

9. The GaN-based compound semiconductor laser element according to claim 1, characterized in that: The lower limiting layer, lower waveguide layer, upper waveguide layer, and upper limiting 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, and BN.

10. The GaN-based compound semiconductor laser element according to claim 1, characterized in that: The substrate includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x , Sapphire / SiO2 / SiN x Any one of a composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

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