A semiconductor laser with an optical absorption loss suppression layer

Abstract

This invention proposes a semiconductor laser with an optical absorption loss suppression layer, comprising, from bottom to top, 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. An optical absorption loss suppression layer is disposed between the electron blocking layer and the upper cladding layer. Both the optical absorption loss suppression layer and the electron blocking layer exhibit trends in dielectric constant variation, effective electron mass variation, and conduction band effective density of states variation. This invention sets these trends in the optical absorption loss suppression layer and the electron blocking layer to regulate the carrier distribution and stimulated emission laser field distribution, thereby distancing the internal light field away from the high absorption regions of the electron blocking layer and the upper cladding layer, and reducing the absorption loss of the light field by unionized Mg acceptors in the high absorption regions.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor optoelectronic devices, and in particular to a semiconductor laser with a light absorption loss suppression layer. BACKGROUND

[0002] Lasers are widely used in laser display, laser television, laser projector, communication, medical treatment, weapon, guidance, distance measurement, spectrum analysis, cutting, precision welding, high-density optical storage and other fields. There are many types of lasers, and the classification methods are also various. The main types of lasers include solid-state, gas, liquid, semiconductor and dye 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 service life, simple and compact structure, and small size.

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

[0004] 1) Laser is generated by stimulated radiation of carriers, with a small spectral half-width and high brightness. The output power of a single laser can reach W level, while the output power of a single nitride semiconductor 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 the nitride light-emitting diode, resulting in stronger electron leakage, more serious Auger recombination, stronger polarization effect, more serious electron-hole mismatch, and more serious efficiency decay Droop effect;

[0006] 3) Light-emitting diode is a spontaneous transition radiation without external action, from high energy level to low energy level of incoherent light, while laser is a stimulated transition radiation, the energy of the induced photon should be equal to the energy level difference of the electron transition, and the generated photon and the induced photon are homophase coherent light.

[0007] 4) Different principles: light-emitting diode is a radiation recombination under the action of external voltage, in which electron-hole transitions to quantum well or p-n junction, while laser needs to meet the lasing conditions, which must meet the carrier inversion distribution in the active region. The stimulated radiation light oscillates back and forth in the resonant cavity, propagates in the gain medium to amplify the light, and finally outputs the laser when the gain is greater than the loss and the threshold condition is met.

[0008] Nitride semiconductor lasers have the following problems: internal optical absorption losses include impurity absorption loss, carrier absorption loss, waveguide sidewall scattering loss, and quantum well absorption loss; high impurity absorption loss in optical waveguides; inherent carbon impurities in p-type semiconductors can compensate for acceptors and destroy p-type properties; low ionization rate of p-type doping (below 10%); a large number of unionized Mg acceptor impurities (above 90%) will produce a self-compensation effect and cause an increase in internal optical loss, resulting in a decrease in laser slope efficiency and an increase in threshold current. Summary of the Invention

[0009] To address one of the aforementioned technical problems, the present invention provides a semiconductor laser with an optical absorption loss suppression layer.

[0010] This invention provides a semiconductor laser with an optical absorption loss suppression layer, comprising, from bottom to top, 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. An optical absorption loss suppression layer is disposed between the electron blocking layer and the upper cladding layer. Both the optical absorption loss suppression layer and the electron blocking layer exhibit trends in dielectric constant variation, effective electron mass variation, and conduction band effective density of states variation. The peak position of the dielectric constant of the optical absorption loss suppression layer is towards the active layer and the upper cladding layer. All of these show a decreasing trend. The valley position of the dielectric constant of the electron blocking layer shows an increasing trend towards the upper cladding layer. The valley position of the effective electron mass of the light absorption loss suppression layer shows an increasing trend towards the active layer and the upper cladding layer. The peak position of the effective electron mass of the electron blocking layer shows a decreasing trend towards the upper cladding layer. The peak position of the effective conduction band state density of the light absorption loss suppression layer shows a decreasing trend towards the active layer and the upper cladding layer. The valley position of the effective conduction band state density of the electron blocking layer shows an increasing trend towards the upper cladding layer.

[0011] Preferably, the angle at which the peak position of the dielectric constant of the light absorption loss suppression layer decreases towards the active layer is α, the angle at which the peak position of the dielectric constant of the light absorption loss suppression layer decreases towards the upper coating layer is β, and the angle at which the valley position of the dielectric constant of the electron blocking layer increases towards the upper coating layer is γ, wherein: 40°≤γ≤β≤α≤90°.

[0012] Preferably, the angle at which the valley position of the effective electron mass of the light absorption loss suppression layer rises towards the active layer is θ, the angle at which the valley position of the effective electron mass of the light absorption loss suppression layer rises towards the upper coating layer is δ, and the angle at which the peak position of the effective electron mass of the electron blocking layer falls towards the upper coating layer is σ, wherein: 45°≤σ≤δ≤θ≤90°.

[0013] Preferably, the peak position of the conduction band effective state density of the optical absorption loss suppression layer decreases at an angle towards the active layer. The angle ψ for the decrease of the peak position of the conduction band effective density of states in the optical absorption loss suppression layer towards the upper cladding layer is ψ, and the angle μ for the increase of the valley position of the conduction band effective density of states in the electron blocking layer towards the upper cladding layer is μ, where:

[0014] Preferably, the dielectric constant distribution of the light absorption loss suppression layer has the function y1 = e x The cosx curve distribution; the effective electron mass distribution of the light absorption loss suppression layer has the function y2 = sinx / e x Curve distribution; the effective state density distribution of the conduction band of the optical absorption loss suppression layer has the function y3 = e x The sinx curve distribution, where x represents the depth of the light absorption loss suppression layer in the direction of the upper coating layer.

[0015] Preferably, both the light absorption loss suppression layer and the electron blocking layer exhibit trends in thermal conductivity, elastic coefficient, and coefficient of thermal expansion. The trough of the thermal conductivity of the light absorption loss suppression layer increases towards both the active layer and the upper cladding layer. The peak of the thermal conductivity of the electron blocking layer decreases towards the upper cladding layer. The peak of the elastic coefficient of the light absorption loss suppression layer decreases towards both the active layer and the upper cladding layer. The trough of the elastic coefficient of the electron blocking layer increases towards the upper cladding layer. The trough of the coefficient of thermal expansion of the light absorption loss suppression layer increases towards both the active layer and the upper cladding layer. The peak of the coefficient of thermal expansion of the electron blocking layer decreases towards the upper cladding layer.

[0016] Preferably, the angle at which the valley of the thermal conductivity of the light absorption loss suppression layer rises toward the active layer is υ, the angle at which the valley of the thermal conductivity of the light absorption loss suppression layer rises toward the upper coating layer is ρ, and the angle at which the peak of the thermal conductivity of the electron blocking layer falls toward the upper coating layer is ω, wherein: 50°≤ω≤ρ≤υ≤90°.

[0017] Preferably, the angle at which the peak position of the elastic coefficient of the light absorption loss suppression layer decreases towards the active layer is ε, the angle at which the peak position of the elastic coefficient of the light absorption loss suppression layer decreases towards the upper coating layer is η, and the angle at which the valley position of the elastic coefficient of the electron blocking layer increases towards the upper coating layer is κ, wherein: 42°≤κ≤η≤ε≤90°.

[0018] Preferably, the angle at which the trough of the thermal expansion coefficient of the light absorption loss suppression layer rises towards the active layer is ζ, the angle at which the trough of the thermal expansion coefficient of the light absorption loss suppression layer rises towards the upper coating layer is χ, and the angle at which the peak of the thermal expansion coefficient of the electron blocking layer falls towards the upper coating layer is τ, wherein: 48°≤τ≤χ≤ζ≤90°.

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

[0020] Preferably, the relationship between the decreasing angle of the peak positions of the dielectric constant, conduction band effective density of states, and elastic modulus of the light absorption loss suppression layer towards the active layer, the decreasing angle of the peak positions of the dielectric constant, conduction band effective density of states, and elastic modulus of the light absorption loss suppression layer towards the upper cladding layer, the increasing angle of the valley positions of the dielectric constant, conduction band effective density of states, and elastic modulus of the electron blocking layer towards the upper cladding layer, the increasing angle of the valley positions of the effective electron mass, thermal conductivity, and coefficient of thermal expansion of the light absorption loss suppression layer towards the active layer, the increasing angle of the valley positions of the effective electron mass, thermal conductivity, and coefficient of thermal expansion of the light absorption loss suppression layer towards the upper cladding layer, and the decreasing angle of the peak positions of the effective electron mass, thermal conductivity, and coefficient of thermal expansion of the electron blocking layer towards the upper cladding layer 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 / AlInGaN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, with a thickness of 5 nm to 1000 nm.

[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, with a thickness of 5nm to 1000nm.

[0023] Preferably, 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, with a thickness of... The thickness ranges from 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 ranging from 10 angstroms 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 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, and sapphire / SiN. x Sapphire / SiO2 / SiN x Composite substrate, sapphire / SiN x Any one of the following: SiO2 composite substrate, 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 optical field modulation layer between the electron blocking layer and the upper cladding layer of the semiconductor laser, and sets the trends of change of dielectric constant, change of effective electron mass and change of effective density of states in the conduction band of the optical absorption loss suppression layer and the electron blocking layer, thereby controlling the carrier distribution and stimulated emission laser optical field distribution of the laser, so that the internal optical field is far away from the high light absorption region of the electron blocking layer and the upper cladding layer, and reducing the absorption loss of the optical field by the unionized Mg acceptors in the high light absorption region. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0028] Figure 1 This is a schematic diagram of the structure of a semiconductor laser with an optical absorption loss suppression layer according to an embodiment of the present invention;

[0029] Figure 2 This is a SIMS secondary ion mass spectrum of the semiconductor laser with an optical absorption loss suppression layer as described in an embodiment of the present invention;

[0030] Figure 3 This is a locally magnified SIMS secondary ion mass spectrum of the semiconductor laser with an optical absorption loss suppression layer as described in an embodiment of the present invention.

[0031] Figure 4 This is a TEM lens electron microscope image of the semiconductor laser with an optical absorption loss suppression layer as described in an embodiment of the present invention;

[0032] Figure 5 This is a TEM lens image of the light absorption loss suppression layer of the semiconductor laser with the light absorption loss suppression layer described in the embodiment of the present invention;

[0033] Figure 6These are TEM images of the lower waveguide layer, active layer, and upper waveguide layer of the semiconductor laser with an optical absorption loss suppression layer as described in an embodiment of the present invention.

[0034] Figure label:

[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. Optical absorption loss suppression layer. Detailed Implementation

[0036] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0037] like Figures 1 to 6 As shown, this embodiment proposes a semiconductor laser with an optical absorption loss suppression layer, comprising, from bottom to top, 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. An optical absorption loss suppression layer 107 is also provided in this semiconductor laser.

[0038] Specifically, in this embodiment, the semiconductor laser with the light absorption loss suppression layer is provided from bottom to top as follows: substrate 100, lower cladding layer 101, lower waveguide layer 102, active layer 103, upper waveguide layer 104, electron blocking layer 105, and upper cladding layer 106. The light absorption loss suppression layer 107 is disposed between the electron blocking layer 105 and the upper cladding layer 106. Both the light absorption loss suppression layer 107 and the electron blocking layer 105 possess dielectric constant characteristics, effective electron mass characteristics, and conduction band effective density of states characteristics, and exhibit a certain variation trend towards the active layer 103 or the upper cladding layer 106, specifically manifested as follows:

[0039] In the optical absorption loss suppression layer 107, the trends of dielectric constant, effective electronic mass, and effective density of states in the conduction band are as follows:

[0040] The peak position of the dielectric constant of the light absorption loss suppression layer 107 shows a decreasing trend towards both the active layer 103 and the upper cladding layer 106.

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

[0042] The peak position of the effective density of states in the conduction band of the light absorption loss suppression layer 107 shows a decreasing trend towards the active layer 103 and the upper cladding layer 106.

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

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

[0045] The peak position of the effective electron mass of the electron blocking layer 105 decreases towards the upper coating layer 106;

[0046] The valley position of the effective density of states in the conduction band of the electron blocking layer 105 shows an upward trend towards the upper coating layer 106.

[0047] In this embodiment, an optical field modulation layer is provided between the electron blocking layer 105 and the upper cladding layer 106 of the semiconductor laser. The trends of change of dielectric constant, change of effective electron mass and change of effective density of states in conduction band are set for the optical absorption loss suppression layer 107 and the electron blocking layer 105. The carrier distribution and the laser optical field distribution of stimulated emission are controlled to keep the internal optical field away from the high light absorption region of the electron blocking layer 105 and the upper cladding layer 106, thereby reducing the absorption loss of the optical field by the unionized Mg acceptors in the high light absorption region.

[0048] Furthermore, the following relationship exists between the changing angles of the dielectric constants of the light absorption loss suppression layer 107 and the electron blocking layer 105: the angle at which the peak position of the dielectric constant of the light absorption loss suppression layer 107 decreases towards the active layer 103 is α; the angle at which the peak position of the dielectric constant of the light absorption loss suppression layer 107 decreases towards the upper cladding layer 106 is β; and the angle at which the valley position of the dielectric constant of the electron blocking layer 105 increases towards the upper cladding layer 106 is γ, where: 40°≤γ≤β≤α≤90°.

[0049] The following relationship exists between the angles of change of the effective electron mass in the light absorption loss suppression layer 107 and the electron blocking layer 105: the angle at which the valley position of the effective electron mass of the light absorption loss suppression layer 107 rises towards the active layer 103 is θ; the angle at which the valley position of the effective electron mass of the light absorption loss suppression layer 107 rises towards the upper cladding layer 106 is δ; and the angle at which the peak position of the effective electron mass of the electron blocking layer 105 falls towards the upper cladding layer 106 is σ, where: 45°≤σ≤δ≤θ≤90°.

[0050] The relationship between the change angle of the conduction band effective density of states in the light absorption loss suppression layer 107 and the electron blocking layer 105 is as follows: the angle at which the peak position of the conduction band effective density of states in the light absorption loss suppression layer 107 decreases towards the active layer 103 is... The angle of descent from the peak position of the conduction band effective density of states of the light absorption loss suppression layer 107 towards the upper cladding layer 106 is ψ, and the angle of ascent from the valley position of the conduction band effective density of states of the electron blocking layer 105 towards the upper cladding layer 106 is μ, where:

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

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

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

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

[0055] Where x is the depth of the light absorption loss suppression layer 107 in the direction of the overlay layer 106.

[0056] In some optional embodiments, both the light absorption loss suppression layer 107 and the electron blocking layer 105 possess thermal conductivity, elastic modulus, and thermal expansion coefficient characteristics, and exhibit a certain variation trend towards the active layer 103 or the upper cladding layer 106, specifically manifested as follows:

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

[0058] The location of the valley of thermal conductivity of the light absorption loss suppression layer 107 shows an upward trend towards both 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 decreasing trend towards 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 towards the active layer 103 and the upper cladding layer 106.

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

[0062] The peak position of the thermal conductivity of the electron blocking layer 105 decreases towards the upper coating layer 106;

[0063] The trough of the elastic modulus of the electron blocking layer 105 increases towards the upper coating layer 106;

[0064] The peak position of the thermal expansion coefficient of the electron blocking layer 105 decreases towards the upper coating layer 106.

[0065] Furthermore, the following relationship exists between the angles of change in thermal conductivity in the light absorption loss suppression layer 107 and the electron blocking layer 105: the angle at which the valley position of the thermal conductivity of the light absorption loss suppression layer 107 rises towards the active layer 103 is υ, the angle at which the valley position of the thermal conductivity of the light absorption loss suppression layer 107 rises towards the upper coating layer 106 is ρ, and the angle at which the peak position of the thermal conductivity of the electron blocking layer 105 falls towards the upper coating layer 106 is ω, where: 50°≤ω≤ρ≤υ≤90°.

[0066] The following relationship exists between the change angles of the elastic coefficients in the light absorption loss suppression layer 107 and the electron blocking layer 105: the angle at which the peak position of the elastic coefficient of the light absorption loss suppression layer 107 decreases towards the active layer 103 is ε; the angle at which the peak position of the elastic coefficient of the light absorption loss suppression layer 107 decreases towards the upper cladding layer 106 is η; and the angle at which the valley position of the elastic coefficient of the electron blocking layer 105 increases towards the upper cladding layer 106 is κ, where: 42°≤κ≤η≤ε≤90°.

[0067] The following relationship exists between the angles of change of the thermal expansion coefficients in the light absorption loss suppression layer 107 and the electron blocking layer 105: the angle at which the valley position of the thermal expansion coefficient of the light absorption loss suppression layer 107 rises towards the active layer 103 is ζ; the angle at which the valley position of the thermal expansion coefficient of the light absorption loss suppression layer 107 rises towards the upper cladding layer 106 is χ; and the angle at which the peak position of the thermal expansion coefficient of the electron blocking layer 105 falls towards the upper cladding layer 106 is τ, where: 48°≤τ≤χ≤ζ≤90°.

[0068] Furthermore, the relationships between the peak positions of the dielectric constant, effective density of states in the conduction band, and elastic modulus of the light absorption loss suppression layer 107 towards the active layer 103, the peak positions of the dielectric constant, effective density of states in the conduction band, and elastic modulus of the light absorption loss suppression layer 107 towards the upper cladding layer 106, the valley positions of the dielectric constant, effective density of states in the conduction band, and elastic modulus of the electron blocking layer 105 towards the upper cladding layer 106, the valley positions of the effective electron mass, thermal conductivity, and coefficient of thermal expansion of the light absorption loss suppression layer 107 towards the active layer 103, the valley positions of the effective electron mass, thermal conductivity, and coefficient of thermal expansion of the light absorption loss suppression layer 107 towards the upper cladding layer 106, and the peak positions of the effective electron mass, thermal conductivity, and coefficient of thermal expansion of the electron blocking layer 105 towards the upper cladding layer 106 are 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 as follows:

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

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

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

[0073] This embodiment controls the thermal stress between the upper cladding layer 106 and the electron blocking layer 105 by designing the change angle and distribution curve of the thermal conductivity, elastic coefficient and thermal expansion coefficient of the light absorption loss suppression layer 107. By controlling the acceptor compensation of the electron blocking layer 105 and the upper cladding layer 106 through strain control, the ionization rate of p-type doping is improved, and light absorption loss is further suppressed.

[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 / AlInGaN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, with a thickness of 5 nm to 1000 nm.

[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, with a thickness of 5 nm to 1000 nm.

[0076] In some alternative embodiments, the active layer 103 is a periodic structure consisting 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, with 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 angstroms 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 alternative 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 The substrate is any one of the following: SiO2 composite substrate 100, magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate 100.

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

[0080]

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

[0082] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A semiconductor laser having a light absorption loss suppressing layer, comprising, from bottom to top, 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, characterized in that, The light absorption loss suppression layer and the electron blocking layer have a thermal conductivity variation trend, an elastic coefficient variation trend and a thermal expansion coefficient variation trend, the valley position of the thermal conductivity of the light absorption loss suppression layer is in an upward trend in the active layer direction and the upper cladding layer direction, the peak position of the thermal conductivity of the electron blocking layer is in a downward trend in the upper cladding layer direction, the peak position of the elastic coefficient of the light absorption loss suppression layer is in a downward trend in the active layer direction and the upper cladding layer direction, the valley position of the elastic coefficient of the electron blocking layer is in an upward trend in the upper cladding layer direction, the valley position of the thermal expansion coefficient of the light absorption loss suppression layer is in an upward trend in the active layer direction and the upper cladding layer direction, and the peak position of the thermal expansion coefficient of the electron blocking layer is in a downward trend in the upper cladding layer direction.

2. The semiconductor laser having a light absorption loss suppression layer according to claim 1, characterized by, The downward angle of the peak position of the dielectric constant of the light absorption loss suppression layer in the active layer direction is α, the downward angle of the peak position of the dielectric constant of the light absorption loss suppression layer in the upper cladding layer direction is β, and the upward angle of the valley position of the dielectric constant of the electron blocking layer in the upper cladding layer direction is γ, wherein: 40°≤γ≤β≤α≤90°; The upward angle of the valley position of the electron effective mass of the light absorption loss suppression layer in the active layer direction is θ, the upward angle of the valley position of the electron effective mass of the light absorption loss suppression layer in the upper cladding layer direction is δ, and the downward angle of the peak position of the electron effective mass of the electron blocking layer in the upper cladding layer direction is σ, wherein: 45°≤σ≤δ≤θ≤90°; The downward angle of the peak position of the conduction band effective state density of the light absorption loss suppression layer in the active layer direction is φ, the downward angle of the peak position of the conduction band effective state density of the light absorption loss suppression layer in the upper cladding layer direction is ψ, and the upward angle of the valley position of the conduction band effective state density of the electron blocking layer in the upper cladding layer direction is μ, wherein: 55°≤μ≤ψ≤φ≤90°.

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

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

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

6. The semiconductor laser having a light absorption loss suppression layer according to claim 4, characterized by, The thermal conductivity distribution of the light absorption loss inhibition layer has a function y4=sinx / e x The elastic coefficient distribution of the light absorption loss inhibition layer has a function y5=e x The thermal expansion coefficient distribution of the light absorption loss inhibition layer has a function y6=sinx / e x The elastic coefficient distribution of the light absorption loss inhibition layer has a function y5=e 7. The semiconductor laser having a light absorption loss suppression layer according to claim 5, wherein The relationship between the falling angle of the peak position of the dielectric constant, the conduction band effective state density, the elastic coefficient of the light absorption loss suppression layer to the active layer direction, the falling angle of the peak position of the dielectric constant, the conduction band effective state density, the elastic coefficient of the light absorption loss suppression layer to the upper cladding layer direction, the rising angle of the valley position of the dielectric constant, the conduction band effective state density, the elastic coefficient of the electron blocking layer to the upper cladding layer direction, the rising angle of the valley position of the electron effective mass, the thermal conductivity, the thermal expansion coefficient of the light absorption loss suppression layer to the active layer direction, the rising angle of the valley position of the electron effective mass, the thermal conductivity, the thermal expansion coefficient of the light absorption loss suppression layer to the upper cladding layer direction, the falling angle of the peak position of the electron effective mass, the thermal conductivity, the thermal expansion coefficient of the electron blocking layer to the upper cladding layer direction is: 40°≤γ≤β≤α≤κ≤η≤ε≤σ≤δ≤θ≤τ≤χ≤ζ≤ω≤p≤υ≤μ≤ψ≤φ≤90°.

8. The semiconductor laser having a light absorption loss suppression layer according to claim 1, characterized by, 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, GaN / AlN superlattice, and the thickness is 5nm to 1000nm.

9. The semiconductor laser having a light absorption loss suppression layer according to claim 1, characterized by, 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, GaN / AlN superlattice, and the thickness is 5nm to 1000nm.

10. The semiconductor laser having a light absorption loss suppression layer according to claim 1, characterized by, 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, diamond, and the thickness is 10 angstrom meters to 150 angstrom meters; 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, diamond, and the thickness is 10 angstrom meters to 200 angstrom meters; 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, diamond. The substrate comprises any one of sapphire, silicon, Ge, SiC, AIN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AIN composite substrate, diamond, graphene, sapphire / SiN x , sapphire / SiO2 / SiN x composite substrate, sapphire / SiN x / SiO2 composite substrate, magnesium aluminate spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2 composite substrate.

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