Semiconductor laser with light absorption loss suppression layer

Abstract

The invention provides a semiconductor laser with a light absorption loss suppression layer, which 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, and is characterized in that the light absorption loss suppression layer is arranged between the electron blocking layer and the upper coating layer; the light absorption loss suppression layer and the electron blocking layer both have a dielectric constant change trend, an electron effective mass change trend and a conduction band effective state density change trend. The dielectric constant change trend, the electron effective mass change trend and the conduction band effective state density change trend in the light absorption loss suppression layer and the electron blocking layer are set, and the carrier distribution of the laser and the laser light field distribution of stimulated radiation are regulated and controlled, so that the internal light field is far away from the highlight absorption area of the electron blocking layer and the upper coating layer; and the absorption loss of a non-ionized Mg acceptor in a high light absorption area to a light field is reduced.

Description

Technical Field

[0001] The present application relates to the field of semiconductor optoelectronic devices, and in particular to a semiconductor laser having a light absorption loss suppression 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: internal optical absorption losses of the laser include impurity absorption losses, carrier absorption losses, waveguide structure sidewall scattering losses, and quantum well absorption losses; optical waveguide impurity absorption losses are high, inherent carbon impurities in p-type semiconductors will compensate for acceptors and destroy the p-type, the p-type doping has a low ionization rate (less than 10%), and a large amount of unionized Mg acceptor impurities (more than 90%) will produce a self-compensation effect and cause an increase in internal optical losses, resulting in a decrease in the laser slope efficiency and an increase in the threshold current. Summary of the invention

[0009] To solve one of the above technical problems, the present invention provides a semiconductor laser having a light absorption loss suppression layer.

[0010] An embodiment of the present invention provides a semiconductor laser with a light absorption loss suppression 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 a light absorption loss suppression layer is arranged between the electron blocking layer and the upper cladding layer, wherein both the light absorption loss suppression layer and the electron blocking layer have a dielectric constant variation trend, an electron effective mass variation trend and a conduction band effective state density variation trend, and the peak position of the dielectric constant of the light absorption loss suppression layer is toward the active layer and the upper cladding layer. Both show a downward trend, the valley position of the dielectric constant of the electron blocking layer shows an upward trend toward the upper cladding layer, the valley position of the electron effective mass of the light absorption loss suppression layer shows an upward trend toward the active layer and the upper cladding layer, the peak position of the electron effective mass of the electron blocking layer shows a downward trend toward the upper cladding layer, the peak position of the conduction band effective state density of the light absorption loss suppression layer shows a downward trend toward the active layer and the upper cladding layer, and the valley position of the conduction band effective state density of the electron blocking layer shows an upward trend toward the upper cladding layer.

[0011] Preferably, the peak position of the dielectric constant of the light absorption loss suppression layer has a decreasing angle α toward the active layer, the peak position of the dielectric constant of the light absorption loss suppression layer has a decreasing angle β toward the upper cladding layer, and the valley position of the dielectric constant of the electron blocking layer has a rising angle γ toward the upper cladding layer, wherein: 40°≤γ≤β≤α≤90°.

[0012] Preferably, the rising angle of the valley position of the electron effective mass of the light absorption loss suppression layer toward the active layer is θ, the rising angle of the valley position of the electron effective mass of the light absorption loss suppression layer toward the upper cladding layer is δ, and the descending angle of the peak position of the electron effective mass of the electron blocking layer toward the upper cladding layer is σ, wherein: 45°≤σ≤δ≤θ≤90°.

[0013] Preferably, the peak position of the conduction band effective state density of the light absorption loss suppression layer decreases at an angle of The descending angle of the peak position of the conduction band effective state density of the light absorption loss suppression layer toward the upper cladding layer is ψ, and the rising angle of the valley position of the conduction band effective state density of the electron blocking layer toward the upper cladding layer is μ, wherein:

[0014] Preferably, the dielectric constant distribution of the light absorption loss suppression layer has a function y1=e x cosx curve distribution; the electron effective mass distribution of the light absorption loss suppression layer has a function y2 = sinx / e x Curve distribution; the conduction band effective state density distribution of the light absorption loss suppression layer has a function y3=e x sinx curve distribution, x is the depth of the light absorption loss suppression layer toward the upper cladding layer.

[0015] Preferably, the light absorption loss suppression layer and the electron blocking layer both have a trend of changing thermal conductivity, a trend of changing elastic coefficient and a trend of changing thermal expansion coefficient. The valley position of the thermal conductivity of the light absorption loss suppression layer shows an upward trend toward the active layer and the upper cladding layer, the peak position of the thermal conductivity of the electron blocking layer shows a downward trend toward the upper cladding layer, the peak position of the elastic coefficient of the light absorption loss suppression layer shows a downward trend toward the active layer and the upper cladding layer, the valley position of the elastic coefficient of the electron blocking layer shows an upward trend toward the upper cladding layer, the valley position of the thermal expansion coefficient of the light absorption loss suppression layer shows an upward trend toward the active layer and the upper cladding layer, and the peak position of the thermal expansion coefficient of the electron blocking layer shows a downward trend toward the upper cladding layer.

[0016] Preferably, the rising angle of the valley position of the thermal conductivity of the light absorption loss suppression layer toward the active layer is υ, the rising angle of the valley position of the thermal conductivity of the light absorption loss suppression layer toward the upper cladding layer is ρ, and the descending angle of the peak position of the thermal conductivity of the electron blocking layer toward the upper cladding layer is ω, wherein: 50°≤ω≤ρ≤υ≤90°.

[0017] Preferably, the descending angle of the peak position of the elastic coefficient of the light absorption loss suppression layer toward the active layer is ε, the descending angle of the peak position of the elastic coefficient of the light absorption loss suppression layer toward the upper cladding layer is η, and the rising angle of the valley position of the elastic coefficient of the electron blocking layer toward the upper cladding layer is κ, wherein: 42°≤κ≤η≤ε≤90°.

[0018] Preferably, the rising angle of the valley position of the thermal expansion coefficient of the light absorption loss suppression layer toward the active layer is ζ, the rising angle of the valley position of the thermal expansion coefficient of the light absorption loss suppression layer toward the upper cladding layer is χ, and the descending angle of the peak position of the thermal expansion coefficient of the electron blocking layer toward the upper cladding layer is τ, wherein: 48°≤τ≤χ≤ζ≤90°.

[0019] Preferably, the thermal conductivity distribution of the light absorption loss suppression layer has a function y4=sinx / e x Curve distribution; the elastic coefficient distribution of the light absorption loss suppression layer has a function y5 = e x cosx curve distribution; the thermal expansion coefficient distribution of the optical absorption loss suppression layer has a function y6 = sinx / e x Curved distribution.

[0020] Preferably, the dielectric constant, conduction band effective state density, and elastic coefficient of the light absorption loss suppression layer have a descending angle toward the active layer, the dielectric constant, conduction band effective state density, and elastic coefficient of the light absorption loss suppression layer have a descending angle toward the upper cladding layer, the dielectric constant, conduction band effective state density, and elastic coefficient of the electron blocking layer have a rising angle toward the upper cladding layer, the electron effective mass, thermal conductivity, and the valley position of the thermal expansion coefficient of the light absorption loss suppression layer have a rising angle toward the active layer, the electron effective mass, thermal conductivity, and the valley position of the thermal expansion coefficient of the light absorption loss suppression layer have a rising angle toward the upper cladding layer, and the electron effective mass, thermal conductivity, and the peak position of the thermal expansion coefficient of the electron blocking layer have a descending angle toward the upper cladding layer. The relationship is as follows:

[0021] Preferably, the light absorption loss suppression layer is any one or any combination of AlGaN, InGaN, GaN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and has a thickness of 5nm to 1000nm.

[0022] Preferably, the upper waveguide layer and the lower waveguide layer are any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and have a thickness of 5nm to 1000nm.

[0023] Preferably, the active layer is a periodic structure composed of a well layer and a barrier layer, 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, and the thickness is 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, with a thickness of 10 to 200 angstroms.

[0024] Preferably, the lower cladding layer, electron blocking layer and 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.

[0025] Preferably, the substrate comprises 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.

[0026] The beneficial effects of the present invention are as follows: the present invention sets a light field regulation layer between the electron blocking layer and the upper cladding layer of the semiconductor laser, and sets the dielectric constant variation trend, the electron effective mass variation trend and the conduction band effective state density variation trend in the light absorption loss suppression layer and the electron blocking layer, regulates the laser carrier distribution and the laser light field distribution of stimulated radiation, keeps the internal light field away from the high light absorption region of the electron blocking layer and the upper cladding layer, and reduces the absorption loss of the light field by the unionized Mg acceptor in the high light absorption region. 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 semiconductor laser with a light absorption loss suppression layer according to an embodiment of the present invention;

[0029] Figure 2 This is a SIMS secondary ion mass spectrum of a semiconductor laser with a light absorption loss suppression layer according to an embodiment of the present invention;

[0030] Figure 3 A locally enlarged SIMS secondary ion mass spectrum of a semiconductor laser with a light absorption loss suppression layer according to an embodiment of the present invention;

[0031] Figure 4 This is a TEM lens electron microscope image of a semiconductor laser with a light absorption loss suppression layer according to an embodiment of the present invention;

[0032] Figure 5 This is a TEM lens electron microscope image of the light absorption loss suppression layer of the semiconductor laser having the light absorption loss suppression layer according to the embodiment of the present invention;

[0033] Figure 6This is a TEM lens electron microscope image of the lower waveguide layer, active layer and upper waveguide layer of the semiconductor laser with a light absorption loss suppression layer according to an embodiment of the present invention.

[0034] Reference numerals:

[0035] 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, 107. light absorption loss suppression layer. DETAILED DESCRIPTION

[0036] 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.

[0037] like Figures 1 to 6 As shown, this embodiment provides a semiconductor laser with a light absorption loss suppression layer, comprising 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. A light absorption loss suppression layer 107 is also provided in the semiconductor laser with a light absorption loss suppression layer.

[0038] Specifically, in this embodiment, the semiconductor laser with a light absorption loss suppression 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 light absorption loss suppression layer 107 is provided between the electron blocking layer 105 and the upper cladding layer 106. The light absorption loss suppression layer 107 and the electron blocking layer 105 both have dielectric constant characteristics, electron effective mass characteristics and conduction band effective state density characteristics, and also present a certain change trend in the direction toward the active layer 103 or the upper cladding layer 106, which is specifically manifested as follows:

[0039] In the light absorption loss suppression layer 107, the variation trends of the dielectric constant, the electron effective mass and the conduction band effective state density are as follows:

[0040] The peak position of the dielectric constant of the light absorption loss suppression layer 107 shows a downward trend toward the active layer 103 and the upper cladding layer 106;

[0041] The valley position of the electron effective mass of the light absorption loss suppression layer 107 shows an upward trend toward the active layer 103 and the upper cladding layer 106;

[0042] The peak position of the conduction band effective state density of the light absorption loss suppression layer 107 shows a downward trend toward the active layer 103 and the upper cladding layer 106;

[0043] In the electron blocking layer 105, the variation trends of the dielectric constant, the electron effective mass and the conduction band effective state density are as follows:

[0044] The valley position of the dielectric constant of the electron blocking layer 105 shows an upward trend toward the upper cladding layer 106;

[0045] The peak position of the electron effective mass of the electron blocking layer 105 shows a downward trend toward the upper cladding layer 106;

[0046] The valley position of the conduction band effective state density of the electron blocking layer 105 shows an upward trend toward the upper cladding layer 106 .

[0047] In this embodiment, a light field control layer is arranged between the electron blocking layer 105 and the upper cladding layer 106 of the semiconductor laser, and the dielectric constant variation trend, the electron effective mass variation trend and the conduction band effective state density variation trend in the light absorption loss suppression layer 107 and the electron blocking layer 105 are set to control the laser carrier distribution and the laser light field distribution of stimulated radiation, so as to keep the internal light field away from the high light absorption area of ​​the electron blocking layer 105 and the upper cladding layer 106, and reduce the absorption loss of the unionized Mg acceptor to the light field in the high light absorption area.

[0048] Furthermore, the change angles of the dielectric constants in the light absorption loss suppression layer 107 and the electron blocking layer 105 have the following relationship: the decreasing angle of the peak position of the dielectric constant of the light absorption loss suppression layer 107 toward the active layer 103 is α, the decreasing angle of the peak position of the dielectric constant of the light absorption loss suppression layer 107 toward the upper cladding layer 106 is β, and the increasing angle of the valley position of the dielectric constant of the electron blocking layer 105 toward the upper cladding layer 106 is γ, wherein: 40°≤γ≤β≤α≤90°.

[0049] The relationship between the changing angles of the effective mass of electrons in the light absorption loss suppression layer 107 and the electron blocking layer 105 is as follows: the rising angle of the valley position of the effective mass of electrons in the light absorption loss suppression layer 107 toward the active layer 103 is θ, the rising angle of the valley position of the effective mass of electrons in the light absorption loss suppression layer 107 toward the upper cladding layer 106 is δ, and the descending angle of the peak position of the effective mass of electrons in the electron blocking layer 105 toward the upper cladding layer 106 is σ, wherein: 45°≤σ≤δ≤θ≤90°.

[0050] The change angles of the conduction band effective state density in the light absorption loss suppression layer 107 and the electron blocking layer 105 have the following relationship: the descending angle of the peak position of the conduction band effective state density of the light absorption loss suppression layer 107 toward the active layer 103 is The peak position of the conduction band effective state density of the light absorption loss suppression layer 107 has a descending angle of ψ toward the upper cladding layer 106, and the valley position of the conduction band effective state density of the electron blocking layer 105 has a rising angle of μ toward the upper cladding layer 106, wherein:

[0051] In some optional embodiments, the dielectric constant distribution, the electron effective mass distribution and the conduction band effective state density distribution in the light absorption loss suppression layer 107 are specifically expressed as follows:

[0052] The dielectric constant distribution of the light absorption loss suppression layer 107 has a function y1=e x cosx curve distribution;

[0053] The electron effective mass distribution of the light absorption loss suppression layer 107 has a function y2=sinx / e x Curve distribution;

[0054] The conduction band effective state density distribution of the light absorption loss suppression layer 107 has a function y3=e x sinx curve distribution;

[0055] Here, x is the depth of the light absorption loss suppression layer 107 in the direction of the upper cladding layer 106 .

[0056] In some optional embodiments, the light absorption loss suppression layer 107 and the electron blocking layer 105 both have thermal conductivity characteristics, elastic coefficient characteristics and thermal expansion coefficient characteristics, and also show a certain change trend in the direction toward the active layer 103 or the upper cladding layer 106, which is specifically manifested as follows:

[0057] In the light absorption loss suppression layer 107, the variation trends of thermal conductivity, elastic coefficient and thermal expansion coefficient are as follows:

[0058] The valley position of the thermal conductivity of the light absorption loss suppression layer 107 shows an upward trend toward the active layer 103 and the upper cladding layer 106;

[0059] The peak position of the elastic coefficient of the light absorption loss suppression layer 107 shows a downward trend toward the active layer 103 and the upper cladding layer 106;

[0060] The valley position of the thermal expansion coefficient of the light absorption loss suppression layer 107 tends to rise toward the active layer 103 and the upper cladding layer 106;

[0061] In the electron blocking layer 105, the variation trends of thermal conductivity, elastic coefficient and thermal expansion coefficient are as follows:

[0062] The peak position of the thermal conductivity of the electron blocking layer 105 shows a decreasing trend toward the upper cladding layer 106;

[0063] The valley position of the elastic coefficient of the electron blocking layer 105 shows an upward trend toward the upper cladding layer 106;

[0064] The peak position of the thermal expansion coefficient of the electron blocking layer 105 shows a decreasing trend toward the upper cladding layer 106 .

[0065] Furthermore, the changing angles of thermal conductivity in the light absorption loss suppression layer 107 and the electron blocking layer 105 have the following relationship: the rising angle of the valley position of the thermal conductivity of the light absorption loss suppression layer 107 toward the active layer 103 is υ, the rising angle of the valley position of the thermal conductivity of the light absorption loss suppression layer 107 toward the upper cladding layer 106 is ρ, and the descending angle of the peak position of the thermal conductivity of the electron blocking layer 105 toward the upper cladding layer 106 is ω, wherein: 50°≤ω≤ρ≤υ≤90°.

[0066] The relationship between the changing angles of the elastic coefficients in the light absorption loss suppression layer 107 and the electron blocking layer 105 is as follows: the decreasing angle of the peak position of the elastic coefficient of the light absorption loss suppression layer 107 toward the active layer 103 is ε, the decreasing angle of the peak position of the elastic coefficient of the light absorption loss suppression layer 107 toward the upper cladding layer 106 is η, and the increasing angle of the valley position of the elastic coefficient of the electron blocking layer 105 toward the upper cladding layer 106 is κ, wherein: 42°≤κ≤η≤ε≤90°.

[0067] The relationship between the changing angles of the thermal expansion coefficients in the light absorption loss suppression layer 107 and the electron blocking layer 105 is as follows: the rising angle of the valley position of the thermal expansion coefficient of the light absorption loss suppression layer 107 toward the active layer 103 is ζ, the rising angle of the valley position of the thermal expansion coefficient of the light absorption loss suppression layer 107 toward the upper cladding layer 106 is χ, and the descending angle of the peak position of the thermal expansion coefficient of the electron blocking layer 105 toward the upper cladding layer 106 is τ, wherein: 48°≤τ≤χ≤ζ≤90°.

[0068] Furthermore, the relationship between the descending angle of the peak position of the dielectric constant, conduction band effective state density, and elastic coefficient of the light absorption loss suppression layer 107 toward the active layer 103, the descending angle of the peak position of the dielectric constant, conduction band effective state density, and elastic coefficient of the light absorption loss suppression layer 107 toward the upper cladding layer 106, the rising angle of the valley position of the dielectric constant, conduction band effective state density, and elastic coefficient of the electron blocking layer 105 toward the upper cladding layer 106, the rising angle of the valley position of the electron effective mass, thermal conductivity, and thermal expansion coefficient of the light absorption loss suppression layer 107 toward the active layer 103, the rising angle of the valley position of the electron effective mass, thermal conductivity, and thermal expansion coefficient of the light absorption loss suppression layer 107 toward the upper cladding layer 106, and the descending angle of the peak position of the electron effective mass, thermal conductivity, and thermal expansion coefficient of the electron blocking layer 105 toward the upper cladding layer 106 is as follows:

[0069] In some optional embodiments, the thermal conductivity distribution, elastic coefficient distribution and thermal expansion coefficient distribution in the light absorption loss suppression layer 107 are specifically expressed as follows:

[0070] The thermal conductivity distribution of the light absorption loss suppression layer 107 has a function y4=sinx / e x Curve distribution;

[0071] The elastic coefficient distribution of the light absorption loss suppression layer 107 has a function y5=e x cosx curve distribution;

[0072] The thermal expansion coefficient distribution of the light absorption loss suppression layer 107 has a function y6=sinx / e x Curved distribution.

[0073] This embodiment designs the change angle and distribution curve of the thermal conductivity, elastic coefficient and thermal expansion coefficient of the light absorption loss suppression layer 107, regulates the thermal stress between the upper cladding layer 106 and the electron blocking layer 105, and regulates the acceptor compensation of the electron blocking layer 105 and the upper cladding layer 106 through strain, thereby improving the ionization rate of p-type doping and further suppressing light absorption loss.

[0074] In some optional embodiments, the light absorption loss suppression layer 107 is any one or any combination of AlGaN, InGaN, GaN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, with a thickness of 5nm to 1000nm.

[0075] In some optional embodiments, the upper waveguide layer 104 and the lower waveguide layer 102 are any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and have a thickness of 5 nm to 1000 nm.

[0076] In some optional embodiments, the active layer 103 is a periodic structure composed of a well layer and a barrier layer. 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, and has a thickness of 10 angstroms to 150 angstroms. 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, with a thickness of 10 to 200 angstroms.

[0077] In some optional embodiments, the lower cladding layer 101, the electron blocking layer 105, and the upper cladding layer 106 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.

[0078] In some optional embodiments, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate 100, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate 100, diamond, graphene, sapphire / SiN x , Sapphire / SiO2 / SiN x Composite substrate 100, sapphire / SiN x / SiO2 composite substrate 100, any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrates 100.

[0079] The following table compares the internal optical losses of a conventional semiconductor laser and a semiconductor laser with a light absorption loss suppression layer proposed in this embodiment:

[0080]

[0081] It can be seen that the semiconductor laser with the light absorption loss suppression layer proposed in this embodiment reduces the internal optical loss compared with the traditional semiconductor laser, and has obvious advantages over the traditional semiconductor laser.

[0082] 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 semiconductor laser having a light absorption loss suppression 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: A light absorption loss suppression layer is arranged between the electron blocking layer and the upper cladding layer. Both the light absorption loss suppression layer and the electron blocking layer have a dielectric constant variation trend, an electron effective mass variation trend and a conduction band effective state density variation trend. The peak position of the dielectric constant of the light absorption loss suppression layer shows a downward trend toward the active layer and the upper cladding layer, the valley position of the dielectric constant of the electron blocking layer shows an upward trend toward the upper cladding layer, the valley position of the electron effective mass of the light absorption loss suppression layer shows an upward trend toward the active layer and the upper cladding layer, the peak position of the electron effective mass of the electron blocking layer shows a downward trend toward the upper cladding layer, the peak position of the conduction band effective state density of the light absorption loss suppression layer shows a downward trend toward the active layer and the upper cladding layer, and the valley position of the conduction band effective state density of the electron blocking layer shows an upward trend toward the upper cladding layer.

2. The semiconductor laser having a light absorption loss suppression layer according to claim 1, characterized in that: The peak position of the dielectric constant of the light absorption loss suppression layer decreases at an angle α toward the active layer, the peak position of the dielectric constant of the light absorption loss suppression layer decreases at an angle β toward the upper cladding layer, and the valley position of the dielectric constant of the electron blocking layer increases at an angle γ toward the upper cladding layer, wherein: 40°≤γ≤β≤α≤90°; The rising angle of the valley position of the electron effective mass of the light absorption loss suppression layer toward the active layer is θ, the rising angle of the valley position of the electron effective mass of the light absorption loss suppression layer toward the upper cladding layer is δ, and the falling angle of the peak position of the electron effective mass of the electron blocking layer toward the upper cladding layer is σ, wherein: 45°≤σ≤δ≤θ≤90°; The descending angle of the peak position of the conduction band effective state density of the light absorption loss suppression layer toward the active layer is The descending angle of the peak position of the conduction band effective state density of the light absorption loss suppression layer toward the upper cladding layer is ψ, and the rising angle of the valley position of the conduction band effective state density of the electron blocking layer toward the upper cladding layer is μ, wherein:

3. The semiconductor laser having a light absorption loss suppression layer according to claim 2, characterized in that: The dielectric constant distribution of the light absorption loss suppression layer has a function y1=e x cosx curve distribution; the electron effective mass distribution of the light absorption loss suppression layer has a function y2 = sinx / e x Curve distribution; the conduction band effective state density distribution of the light absorption loss suppression layer has a function y3=e x The sinx curve is distributed, where x is the depth of the light absorption loss suppression layer toward the upper cladding layer.

4. The semiconductor laser having a light absorption loss suppression layer according to claim 2, characterized in that: The light absorption loss suppression layer and the electron blocking layer both have a trend of changing thermal conductivity, a trend of changing elastic coefficient and a trend of changing thermal expansion coefficient. The valley position of the thermal conductivity of the light absorption loss suppression layer shows an upward trend toward the active layer and the upper cladding layer, the peak position of the thermal conductivity of the electron blocking layer shows a downward trend toward the upper cladding layer, the peak position of the elastic coefficient of the light absorption loss suppression layer shows a downward trend toward the active layer and the upper cladding layer, the valley position of the elastic coefficient of the electron blocking layer shows an upward trend toward the upper cladding layer, the valley position of the thermal expansion coefficient of the light absorption loss suppression layer shows an upward trend toward the active layer and the upper cladding layer, and the peak position of the thermal expansion coefficient of the electron blocking layer shows a downward trend toward the upper cladding layer.

5. The semiconductor laser having a light absorption loss suppression layer according to claim 4, characterized in that: The rising angle of the valley position of the thermal conductivity of the light absorption loss suppression layer toward the active layer is υ, the rising angle of the valley position of the thermal conductivity of the light absorption loss suppression layer toward the upper cladding layer is ρ, and the falling angle of the peak position of the thermal conductivity of the electron blocking layer toward the upper cladding layer is ω, wherein: 50°≤ω≤ρ≤υ≤90°; The descending angle of the peak position of the elastic coefficient of the light absorption loss suppression layer toward the active layer is ε, the descending angle of the peak position of the elastic coefficient of the light absorption loss suppression layer toward the upper cladding layer is η, and the rising angle of the valley position of the elastic coefficient of the electron blocking layer toward the upper cladding layer is κ, wherein: 42°≤κ≤η≤ε≤90°; The rising angle of the valley position of the thermal expansion coefficient of the light absorption loss suppression layer toward the active layer is ζ, the rising angle of the valley position of the thermal expansion coefficient of the light absorption loss suppression layer toward the upper cladding layer is χ, and the descending angle of the peak position of the thermal expansion coefficient of the electron blocking layer toward the upper cladding layer is τ, wherein: 48°≤τ≤χ≤ζ≤90°.

6. The semiconductor laser having a light absorption loss suppression layer according to claim 4, characterized in that: The thermal conductivity distribution of the light absorption loss suppression layer has a function y4=sinx / e x Curve distribution; the elastic coefficient distribution of the light absorption loss suppression layer has a function y5 = e x cosx curve distribution; the thermal expansion coefficient distribution of the optical absorption loss suppression layer has a function y6 = sinx / e x Curved distribution.

7. The semiconductor laser having a light absorption loss suppression layer according to claim 5, characterized in that: The relationship between the descending angle of the peak position of the dielectric constant, conduction band effective state density, and elastic coefficient of the light absorption loss suppression layer toward the active layer, the descending angle of the peak position of the dielectric constant, conduction band effective state density, and elastic coefficient of the light absorption loss suppression layer toward the upper cladding layer, the rising angle of the valley position of the dielectric constant, conduction band effective state density, and elastic coefficient of the electron blocking layer toward the upper cladding layer, the rising angle of the valley position of the electron effective mass, thermal conductivity, and thermal expansion coefficient of the light absorption loss suppression layer toward the active layer, the rising angle of the valley position of the electron effective mass, thermal conductivity, and thermal expansion coefficient of the light absorption loss suppression layer toward the upper cladding layer, and the descending angle of the peak position of the electron effective mass, thermal conductivity, and thermal expansion coefficient of the electron blocking layer toward the upper cladding layer is:

8. The semiconductor laser having a light absorption loss suppression layer according to claim 1, characterized in that: The light absorption loss suppression layer is any one or any combination of AlGaN, InGaN, GaN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and has a thickness of 5nm to 1000nm.

9. The semiconductor laser having a light absorption loss suppression layer according to claim 1, characterized in that: The upper waveguide layer and the lower waveguide layer are any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and have a thickness of 5nm to 1000nm.

10. The semiconductor laser having a light absorption loss suppression 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 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 150 angstroms; 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, with a thickness of 10 angstroms to 200 angstroms; The lower cladding 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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