A GaN-based semiconductor laser with a limiting factor enhancement layer

Abstract

The present invention discloses a GaN-based semiconductor laser with a confinement factor enhancement layer, which sequentially includes 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 from bottom to top. There is a confinement factor enhancement layer between the electron blocking layer and the upper cladding layer, and the confinement factor enhancement layer includes a first confinement factor enhancement layer and a second confinement factor enhancement layer; the thickness of the confinement factor enhancement layer is 5-1000 nm. The present invention designs the refractive index coefficient, electron mobility, breakdown field strength, and electron affinity change angles and change curves of the first confinement factor enhancement layer and the second confinement factor enhancement layer, regulates the effective refractive index difference to achieve a high kink level, realizes a far-field FFP image with a low aspect ratio, reduces the horizontal divergence angle, reduces stray light and leakage light, reduces the far-field FFP image of local interference, and improves the optical confinement effect and the beam quality factor.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor optoelectronic devices, and in particular to a GaN-based semiconductor laser with a confinement factor enhancement layer. Background Art

[0002] Lasers are widely used in the fields of laser display, laser TV, laser projector, communication, medical treatment, weapons, guidance, ranging, spectral analysis, cutting, precision welding, high-density optical storage, etc. There are many types of lasers and various classification methods. The main types 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 life, simple and compact structure, and miniaturization.

[0003] There are significant differences between lasers and nitride semiconductor light-emitting diodes. 1) Laser is generated by stimulated emission of carriers, with a relatively small spectral full width at half maximum, high brightness, and the output power of a single laser can be in the watt level, while nitride semiconductor light-emitting diodes are spontaneous emission, and the output power of a single light-emitting diode is in the milliwatt level. 2) The operating current density of lasers reaches KA / cm 2 , which is more than two orders of magnitude higher than that of nitride light-emitting diodes, resulting in stronger electron leakage, more serious Auger recombination, stronger polarization effect, and more serious electron-hole mismatch, leading to a more serious efficiency droop effect. 3) Light-emitting diodes are spontaneous transition radiation, and without external action, they are incoherent light that transitions from a high energy level to a low energy level, while lasers are stimulated transition radiation, and the induced photon energy should be equal to the energy difference between the electron transitions, generating completely identical coherent light of photons and induced photons. 4) The principles are different: light-emitting diodes generate radiative recombination luminescence when electrons and holes transition to the active layer or p-n junction under the action of an external voltage, while lasers can only lasing when the lasing conditions are met. It must satisfy the carrier population inversion distribution in the active region, and the stimulated radiation light oscillates back and forth in the resonant cavity. The propagation in the gain medium amplifies the light, satisfies the threshold condition that the gain is greater than the loss, and finally outputs laser light.

[0004] Nitride semiconductor lasers have the following problems: the refractive index dispersion of lasers, the high-concentration carrier concentration fluctuations affect the refractive index of the active layer, the confinement factor decreases with the increase of wavelength, resulting in a reduction in the mode gain of the laser. There is dissipation in the optical field of the confinement layer, and the optical field mode leaks to the substrate to form a standing wave, which leads to low substrate mode suppression efficiency and poor far-field image FFP quality. Summary of the Invention

[0005] The present invention proposes a GaN-based semiconductor laser with a confinement factor enhancement layer, designs the refractive index coefficient, electron mobility, breakdown field strength, and the variation angles and curves of the electron affinity of the first confinement factor enhancement layer and the second confinement factor enhancement layer, regulates the effective refractive index difference to achieve a high kink level, realizes a far-field FFP image with a low aspect ratio, reduces the horizontal divergence angle, reduces stray light and leakage light, reduces the far-field FFP image of local interference, and improves the optical confinement effect and the beam quality factor.

[0006] A GaN-based semiconductor laser with a confinement factor enhancement layer provided by the present invention sequentially includes 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 from bottom to top. There is a confinement factor enhancement layer between the electron blocking layer and the upper cladding layer. The confinement factor enhancement layer includes a first confinement factor enhancement layer and a second confinement factor enhancement layer; the confinement factor enhancement 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 has a thickness of 5 - 1000 nm.

[0007] Preferably, the rising angle of the valley position of the refractive index coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer is α, the descending angle of the peak position of the refractive index coefficient of the second confinement factor enhancement layer in the direction of the active layer is β, and the descending angle of the peak position of the refractive index coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer is γ, where: 45° ≤ γ ≤ β ≤ α ≤ 90°;

[0008] The rising angle of the valley position of the electron mobility of the first confinement factor enhancement layer in the direction of the upper cladding layer is θ, the descending angle of the peak position of the electron mobility of the second confinement factor enhancement layer in the direction of the active layer is δ, and the descending angle of the peak position of the electron mobility of the second confinement factor enhancement layer in the direction of the upper cladding layer is σ, where: 70° ≤ σ ≤ δ ≤ θ ≤ 90°;

[0009] The rising angle of the valley position of the breakdown field strength of the first confinement factor enhancement layer in the direction of the upper cladding layer is φ, the descending angle of the peak position of the breakdown field strength of the second confinement factor enhancement layer in the direction of the active layer is ψ, and the descending angle of the peak position of the breakdown field strength of the second confinement factor enhancement layer in the direction of the upper cladding layer is μ, where: 60° ≤ μ ≤ ψ ≤ φ ≤ 90°;

[0010] The upward rising angle of the valley position of the electron affinity of the first confinement factor enhancement layer in the direction of the upper cladding layer is υ, the downward falling angle of the peak position of the electron affinity of the second confinement factor enhancement layer in the direction of the active layer is ρ, and the downward falling angle of the peak position of the electron affinity of the second confinement factor enhancement layer in the direction of the upper cladding layer is ω, where: 65° ≤ ω ≤ ρ ≤ υ ≤ 90°.

[0011] Preferably, the upward rising angle of the valley position of the Phillips ionization degree of the first confinement factor enhancement layer in the direction of the upper cladding layer is ε, the downward falling angle of the peak position of the Phillips ionization degree of the second confinement factor enhancement layer in the direction of the active layer is η, and the downward falling angle of the peak position of the Phillips ionization degree of the second confinement factor enhancement layer in the direction of the upper cladding layer is κ, where: 48° ≤ κ ≤ η ≤ ε ≤ 90°;

[0012] The upward rising angle of the valley position of the spontaneous polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer is ζ, the downward falling angle of the peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer is χ, and the downward falling angle of the peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer is ν, where: 55° ≤ ν ≤ χ ≤ ζ ≤ 90°;

[0013] The downward falling angle of the peak position of the piezoelectric polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer is τ, the upward rising angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer is λ, and the upward rising angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer is ξ, where: 50° ≤ ξ ≤ λ ≤ τ ≤ 90°.

[0014] Preferably, the upward rising angles of the refractive index coefficient, electron mobility, breakdown field strength, electron affinity, Phillips ionization degree, and valley position of the spontaneous polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer, the downward falling angles of the refractive index coefficient, electron mobility, breakdown field strength, electron affinity, Phillips ionization degree, and peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer, the downward falling angles of the refractive index coefficient, electron mobility, breakdown field strength, electron affinity, Phillips ionization degree, and peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer, the downward falling angle of the peak position of the piezoelectric polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer, the upward rising angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer, and the upward rising angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer have the following relationship: 45° ≤ γ ≤ β ≤ α ≤ κ ≤ η ≤ ε ≤ ξ ≤ λ ≤ τ ≤ ν ≤ χ ≤ ζ ≤ μ ≤ ψ ≤ φ ≤ ω ≤ ρ ≤ υ ≤ σ ≤ δ ≤ θ ≤ 90°.

[0015] Preferably, the refractive index coefficient of the first confinement factor enhancement layer has a curve distribution in the first quadrant of the function y = x -A (A > 1, odd number) of the function y = x -B (B > 1, odd number) of the function y = x -C (C > 1, odd number) of the function y = x -D (D > 1, odd number) of the function y = x -E (E > 1, odd number) of the function y = x -F (F > 1, odd number) of the function y = x x Curve distribution.

[0016] Preferably, the refractive index coefficient of the second confinement factor enhancement layer has a curve distribution of the function y = Gx 2 + Hx + I (G < 0); the electron mobility of the second confinement factor enhancement layer has a curve distribution of the function y = Jx 2 + Kx + L (J < 0); the breakdown field strength of the second confinement factor enhancement layer has a curve distribution of the function y = Mx 2 + Nx + O (M < 0); the electron affinity of the second confinement factor enhancement layer has a curve distribution of the function y = Px 2 + Qx + R (P < 0); the Philips ionization degree of the second confinement factor enhancement layer has a curve distribution of the function y = Sx 2 + Tx + U (S < 0); where: G ≤ S ≤ M ≤ P ≤ J < 0; the spontaneous polarization coefficient of the second confinement factor enhancement layer has a curve distribution in the fourth quadrant of the function y = x / sinx; the piezoelectric polarization coefficient of the second confinement factor enhancement layer has a curve distribution of the function y = x 2 - sinx curve distribution.

[0017] Preferably, the active layer is a periodic structure composed of well layers and barrier layers, where the number of periods satisfies 3≥m≥1. 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, with a thickness of 10 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, diamond, with a thickness of 10 to 200 angstroms.

[0018] 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, GaN / AlN superlattice, with a thickness of 5 to 1000 nm.

[0019] Preferably, 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.

[0020] Preferably, the substrate includes any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, 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

[0021] Compared with the prior art, a GaN-based semiconductor laser with a confinement factor enhancement layer provided by an embodiment of the present invention has the following beneficial effects: designing the refractive index coefficient, electron mobility, breakdown field strength, and the change angles and curves of electron affinity of the first confinement factor enhancement layer and the second confinement factor enhancement layer, regulating the effective refractive index difference to achieve a high kink level, realizing a far-field FFP image with a low aspect ratio, reducing the horizontal divergence angle, reducing stray light and leakage light, reducing the far-field FFP image of local interference, and enhancing the optical confinement effect and beam quality factor; at the same time, designing the change angles and curves of the Philip ionization degree, spontaneous polarization coefficient, and piezoelectric polarization coefficient of the first confinement factor enhancement layer and the second confinement factor enhancement layer, regulating the polarization field and electric field of the laser, enhancing the localization of carriers, reducing the free carrier absorption loss, enhancing the relaxation oscillation frequency, reducing the influence of high-concentration carrier concentration fluctuations on the confinement factor, and enhancing the mode gain, confinement factor, and responsivity of the laser. Description of the Drawings

[0022] Figure 1 is a schematic structural diagram of a GaN-based semiconductor laser with a confinement factor enhancement layer according to an embodiment of the present invention;

[0023] Figure 2 is a SIMS secondary ion mass spectrometry diagram of the structure of a GaN-based semiconductor laser with a confinement factor enhancement layer according to an embodiment of the present invention;

[0024] Figure 3 is a SIMS secondary ion mass spectrometry diagram of the structure of a GaN-based semiconductor laser with a confinement factor enhancement layer according to an embodiment of the present invention;

[0025] Figure 4 is a TEM lens electron microscopy diagram of a GaN-based semiconductor laser with a confinement factor enhancement layer according to an embodiment of the present invention;

[0026] Figure 5It is a TEM lens electron micrograph (partial enlarged view) of a GaN-based semiconductor laser with a confinement factor enhancement layer according to an embodiment of the present invention;

[0027] Figure 6 It is a TEM lens electron micrograph (partial enlarged view) of a GaN-based semiconductor laser with a confinement factor enhancement layer according to an embodiment of the present invention;

[0028] Reference numerals: 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: confinement factor enhancement layer. Detailed implementation manners

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0030] To solve the above problems, a GaN-based semiconductor laser with a confinement factor enhancement layer provided in the embodiments of the present application will be introduced and described in detail through the following specific embodiments.

[0031] Refer to Figure 1-6 , a GaN-based semiconductor laser with a confinement factor enhancement layer provided by the present invention includes, 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. There is a confinement factor enhancement layer 107 between the electron blocking layer 105 and the upper cladding layer 106. The confinement factor enhancement layer 107 includes a first confinement factor enhancement layer and a second confinement factor enhancement layer; the confinement factor enhancement 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, GaN / AlN superlattice, and has a thickness of 5 - 1000 nm.

[0032] The upward rising angle of the valley position of the refractive index coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer 106 is α, the downward falling angle of the peak position of the refractive index coefficient of the second confinement factor enhancement layer in the direction of the active layer 103 is β, and the downward falling angle of the peak position of the refractive index coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer 106 is γ, where: 45° ≤ γ ≤ β ≤ α ≤ 90°;

[0033] The upward rising angle of the valley position of the electron mobility of the first confinement factor enhancement layer in the direction of the upper cladding layer 106 is θ, the downward falling angle of the peak position of the electron mobility of the second confinement factor enhancement layer in the direction of the active layer 103 is δ, and the downward falling angle of the peak position of the electron mobility of the second confinement factor enhancement layer in the direction of the upper cladding layer 106 is σ, where: 70° ≤ σ ≤ δ ≤ θ ≤ 90°;

[0034] The upward rising angle of the valley position of the breakdown field strength of the first confinement factor enhancement layer in the direction of the upper cladding layer 106 is φ, the downward falling angle of the peak position of the breakdown field strength of the second confinement factor enhancement layer in the direction of the active layer 103 is ψ, and the downward falling angle of the peak position of the breakdown field strength of the second confinement factor enhancement layer in the direction of the upper cladding layer 106 is μ, where: 60° ≤ μ ≤ ψ ≤ φ ≤ 90°;

[0035] The upward rising angle of the valley position of the electron affinity of the first confinement factor enhancement layer in the direction of the upper cladding layer 106 is υ, the downward falling angle of the peak position of the electron affinity of the second confinement factor enhancement layer in the direction of the active layer 103 is ρ, and the downward falling angle of the peak position of the electron affinity of the second confinement factor enhancement layer in the direction of the upper cladding layer 106 is ω, where: 65° ≤ ω ≤ ρ ≤ υ ≤ 90°.

[0036] The upward rising angle of the valley position of the Phillips ionization degree of the first confinement factor enhancement layer in the direction of the upper cladding layer 106 is ε, the downward falling angle of the peak position of the Phillips ionization degree of the second confinement factor enhancement layer in the direction of the active layer 103 is η, and the downward falling angle of the peak position of the Phillips ionization degree of the second confinement factor enhancement layer in the direction of the upper cladding layer 106 is κ, where: 48° ≤ κ ≤ η ≤ ε ≤ 90°;

[0037] The upward rising angle of the valley position of the spontaneous polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer 106 is ζ, the downward falling angle of the peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer 103 is χ, and the downward falling angle of the peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer 106 is ν, where: 55° ≤ ν ≤ χ ≤ ζ ≤ 90°;

[0038] The downward angle of the peak position of the piezoelectric polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer 106 is τ, the upward angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer 103 is λ, and the upward angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer 106 is ξ, where: 50° ≤ ξ ≤ λ ≤ τ ≤ 90°.

[0039] In summary, the upward angle of the valley position of the refractive index coefficient, electron mobility, breakdown field strength, electron affinity, Phillips ionization degree, and spontaneous polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer 106, the downward angle of the peak position of the refractive index coefficient, electron mobility, breakdown field strength, electron affinity, Phillips ionization degree, and spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer 103, the downward angle of the peak position of the refractive index coefficient, electron mobility, breakdown field strength, electron affinity, Phillips ionization degree, and spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer 106, the downward angle of the peak position of the piezoelectric polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer 106, the upward angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer 103, and the upward angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer have the following relationship: 45° ≤ γ ≤ β ≤ α ≤ κ ≤ η ≤ ε ≤ ξ ≤ λ ≤ τ ≤ ν ≤ χ ≤ ζ ≤ μ ≤ ψ ≤ φ ≤ ω ≤ ρ ≤ υ ≤ σ ≤ δ ≤ θ ≤ 90°.

[0040] The refractive index coefficient of the first confinement factor enhancement layer has a curve distribution of the function y = x -A (A > 1, odd number) in the first quadrant; the electron mobility of the first confinement factor enhancement layer has a curve distribution of the function y = x -B (B > 1, odd number) in the first quadrant; the breakdown field strength of the first confinement factor enhancement layer has a curve distribution of the function y = x -C (C > 1, odd number) in the first quadrant; the electron affinity of the first confinement factor enhancement layer has a curve distribution of the function y = x -D (D > 1, odd number) in the first quadrant; the Phillips ionization degree of the first confinement factor enhancement layer has a curve distribution of the function y = x -E (E > 1, odd number) in the first quadrant; the spontaneous polarization coefficient of the first confinement factor enhancement layer has a curve distribution of the function y = x -F (F > 1, odd number) in the first quadrant; where: 1 < B ≤ D ≤ C ≤ F ≤ E ≤ A; the piezoelectric polarization coefficient of the first confinement factor enhancement layer has a curve distribution of the function y = lnx / e x Curve distribution.

[0041] The refractive index coefficient of the second confinement factor enhancement layer has a curve distribution of the function y = Gx 2 + Hx + I (G < 0); the electron mobility of the second confinement factor enhancement layer has a curve distribution of the function y = Jx 2 + Kx + L (J < 0); the breakdown field strength of the second confinement factor enhancement layer has a curve distribution of the function y = Mx 2 + Nx + O (M < 0); the electron affinity of the second confinement factor enhancement layer has a curve distribution of the function y = Px 2 + Qx + R (P < 0); the Phillips ionization degree of the second confinement factor enhancement layer has a curve distribution of the function y = Sx 2 + Tx + U (S < 0); where: G ≤ S ≤ M ≤ P ≤ J < 0; the spontaneous polarization coefficient of the second confinement factor enhancement layer has a curve distribution in the fourth quadrant of the function y = x / sinx; the piezoelectric polarization coefficient of the second confinement factor enhancement layer has a curve distribution of the function y = x 2 - sinx curve distribution.

[0042] The present invention designs the change angles and change curves of the refractive index coefficient, electron mobility, breakdown field strength, and electron affinity of the first confinement factor enhancement layer and the second confinement factor enhancement layer, regulates the effective refractive index difference to achieve a high kink level, realizes a far-field FFP image with a low aspect ratio, reduces the horizontal divergence angle, reduces stray light and leakage light, reduces the far-field FFP image with local interference, and improves the optical confinement effect and the beam quality factor.

[0043] The present invention designs the change angles and change curves of the Phillips ionization degree, spontaneous polarization coefficient, and piezoelectric polarization coefficient of the first confinement factor enhancement layer and the second confinement factor enhancement layer, regulates the polarization field and electric field of the laser, improves the localization of carriers, reduces the free carrier absorption loss, enhances the relaxation oscillation frequency, reduces the influence of high-concentration carrier concentration fluctuations on the confinement factor, and improves the mode gain, confinement factor, and responsivity of the laser.

[0044] Specifically, as shown in the following table, compare the data of the traditional laser and the laser of the present invention.

[0045] Blue laser - project Traditional laser Laser of the present invention Variation range <![CDATA[Beam quality factor M 2 > 1.89 1.14 66％ Limiting factor 1.50％ 2.31％ 54％ Horizontal divergence angle 20～50° 5～25°

[0046] In the present invention, the active layer 103 is a periodic structure composed of well layers and barrier layers, with the number of periods 3≥m≥1. 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, with a thickness of 10 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, diamond, with a thickness of 10 to 200 angstroms.

[0047] In the present invention, 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, GaN / AlN superlattice, with a thickness of 5 to 1000 nm.

[0048] In the present invention, 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, diamond.

[0049] In the present invention, the substrate 100 includes any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, 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

[0050] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A GaN-based semiconductor laser with a limiting factor enhancement layer, which sequentially includes 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) from bottom to top, and is characterized in that, There is a confinement factor enhancement layer (107) between the electron blocking layer (105) and the upper cladding layer (106), and the confinement factor enhancement layer (107) includes a first confinement factor enhancement layer and a second confinement factor enhancement layer; the confinement factor enhancement 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, GaN / AlN superlattice, with a thickness of 5 - 1000 nm; The rising angle of the valley position of the refractive index coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer (106) is α, the falling angle of the peak position of the refractive index coefficient of the second confinement factor enhancement layer in the direction of the active layer (103) is β, and the falling angle of the peak position of the refractive index coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer (106) is γ, where: 45° ≤ γ ≤ β ≤ α ≤ 90°; The rising angle of the valley position of the electron mobility of the first confinement factor enhancement layer in the direction of the upper cladding layer (106) is θ, the falling angle of the peak position of the electron mobility of the second confinement factor enhancement layer in the direction of the active layer (103) is δ, and the falling angle of the peak position of the electron mobility of the second confinement factor enhancement layer in the direction of the upper cladding layer (106) is σ, where: 70° ≤ σ ≤ δ ≤ θ ≤ 90°; The rising angle of the valley position of the breakdown field strength of the first confinement factor enhancement layer in the direction of the upper cladding layer (106) is φ, the falling angle of the peak position of the breakdown field strength of the second confinement factor enhancement layer in the direction of the active layer (103) is ψ, and the falling angle of the peak position of the breakdown field strength of the second confinement factor enhancement layer in the direction of the upper cladding layer (106) is μ, where: 60° ≤ μ ≤ ψ ≤ φ ≤ 90°; The rising angle of the valley position of the electron affinity of the first confinement factor enhancement layer in the direction of the upper cladding layer (106) is υ, the falling angle of the peak position of the electron affinity of the second confinement factor enhancement layer in the direction of the active layer (103) is ρ, and the falling angle of the peak position of the electron affinity of the second confinement factor enhancement layer in the direction of the upper cladding layer (106) is ω, where: 65° ≤ ω ≤ ρ ≤ υ ≤ 90°; The rising angle of the valley position of the Phillips ionization degree of the first confinement factor enhancement layer in the direction of the upper cladding layer (106) is ε, the falling angle of the peak position of the Phillips ionization degree of the second confinement factor enhancement layer in the direction of the active layer (103) is η, and the falling angle of the peak position of the Phillips ionization degree of the second confinement factor enhancement layer in the direction of the upper cladding layer (106) is κ, where: 48° ≤ κ ≤ η ≤ ε ≤ 90°; The upward rising angle of the valley position of the spontaneous polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer (106) is ζ, the downward falling angle of the peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer (103) is χ, and the downward falling angle of the peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer (106) is ν, where: 55° ≤ ν ≤ χ ≤ ζ ≤ 90°; The downward falling angle of the peak position of the piezoelectric polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer (106) is τ, the upward rising angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer (103) is λ, and the upward rising angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer (106) is ξ, where: 50° ≤ ξ ≤ λ ≤ τ ≤ 90°.

2. A GaN-based semiconductor laser having a limiting factor enhancement layer according to any one of claims 1, wherein, The refractive index coefficient, electron mobility, breakdown field strength, electron affinity, Philips ionization degree, and the upward rising angle of the valley position of the spontaneous polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer (106), the refractive index coefficient, electron mobility, breakdown field strength, electron affinity, Philips ionization degree, and the downward falling angle of the peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer (103), the refractive index coefficient, electron mobility, breakdown field strength, electron affinity, Philips ionization degree, and the downward falling angle of the peak position of the spontaneous polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer (106), the downward falling angle of the peak position of the piezoelectric polarization coefficient of the first confinement factor enhancement layer in the direction of the upper cladding layer (106), the upward rising angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the active layer (103), and the upward rising angle of the valley position of the piezoelectric polarization coefficient of the second confinement factor enhancement layer in the direction of the upper cladding layer have the following relationship: 45° ≤ γ ≤ β ≤ α ≤ κ ≤ η ≤ ε ≤ ξ ≤ λ ≤ τ ≤ ν ≤ χ ≤ ζ ≤ μ ≤ ψ ≤ φ ≤ ω ≤ ρ ≤ υ ≤ σ ≤ δ ≤ θ ≤ 90°.

3. The GaN-based semiconductor laser with a limiting factor enhancement layer according to claim 1, characterized in that, The refractive index coefficient of the first confinement factor enhancement layer has a function y = x -A (A > 1, odd number) in the first quadrant curve distribution; the electron mobility of the first confinement factor enhancement layer has a function y = x -B (B > 1, odd number) in the first quadrant curve distribution; the breakdown field strength of the first confinement factor enhancement layer has a function y = x -C (C > 1, odd number) in the first quadrant curve distribution; the electron affinity of the first confinement factor enhancement layer has a function y = x -D (D > 1, odd number) in the first quadrant curve distribution; the Phillips ionization degree of the first confinement factor enhancement layer has a function y = x -E (E > 1, odd number) in the first quadrant curve distribution; the spontaneous polarization coefficient of the first confinement factor enhancement layer has a function y = x -F (F > 1, odd number) in the first quadrant curve distribution; where: 1 < B ≤ D ≤ C ≤ F ≤ E ≤ A; the piezoelectric polarization coefficient of the first confinement factor enhancement layer has a function y = lnx / e x Curve distribution.

4. The GaN-based semiconductor laser with a limiting factor enhancement layer according to claim 1, characterized in that, The refractive index coefficient of the second confinement factor enhancement layer has a curve distribution of the function y = Gx 2 + Hx + I (G < 0); the electron mobility of the second confinement factor enhancement layer has a curve distribution of the function y = Jx 2 + Kx + L (J < 0); the breakdown field strength of the second confinement factor enhancement layer has a curve distribution of the function y = Mx 2 + Nx + O (M < 0); the electron affinity of the second confinement factor enhancement layer has a curve distribution of the function y = Px 2 + Qx + R (P < 0); the Phillips ionization degree of the second confinement factor enhancement layer has a curve distribution of the function y = Sx 2 + Tx + U (S < 0); where: G ≤ S ≤ M ≤ P ≤ J < 0; the spontaneous polarization coefficient of the second confinement factor enhancement layer has a curve distribution in the fourth quadrant of the function y = x / sinx; the piezoelectric polarization coefficient of the second confinement factor enhancement layer has a curve distribution of the function y = x 2 - sinx curve distribution.

5. The GaN-based semiconductor laser with a limiting factor enhancement layer according to claim 1, characterized in that, The active layer (103) is a periodic structure composed of well layers and barrier layers, where the number of periods satisfies 3≥m≥1. 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, with a thickness of 10 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, diamond, with a thickness of 10 to 200 angstroms.

6. The GaN-based semiconductor laser with a limiting factor enhancement layer according to claim 1, characterized in that 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, GaN / AlN superlattice, with a thickness of 5 to 1000 nm.

7. The GaN-based semiconductor laser with a limiting factor enhancement layer according to claim 1, characterized in that, 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, diamond.

8. The GaN-based semiconductor laser with a limiting factor enhancement layer according to claim 1, characterized in that, The substrate (100) includes any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, graphene, sapphire / SiN x composite substrate, 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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