A semiconductor laser element

Abstract

The present invention discloses a semiconductor laser element, which comprises, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer. A dark exciton resonance layer is provided between the lower confinement layer and the lower waveguide layer. The dark exciton resonance layer comprises a first dark exciton resonance layer, a second dark exciton resonance layer, and a third dark exciton resonance layer. The specific electron effective mass distribution and refractive index distribution of the dark exciton resonance layer of the present invention enhance the strong coupling effect between dark excitons and photons, reduce the effective mass of exciton polaritons and increase the group velocity, enhance the dipole resonance intensity and the nonlinear effect of exciton polaritons, enhance the coherence of dark exciton polaritons, reduce the laser mode number, increase the photon degeneracy, improve the output laser coherence, and improve 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 semiconductor laser element. Background Art

[0002] Lasers are widely used in laser displays, laser televisions, laser projectors, communications, medical treatment, weaponry, guidance, rangefinders, spectral analysis, cutting, precision welding, high-density optical storage, and other fields. There are many different types of lasers, classified in various ways, including solid-state, gas, liquid, semiconductor, and dye lasers. Compared with other types of lasers, all-solid-state semiconductor lasers offer advantages such as small size, high efficiency, light weight, excellent stability, long life, simple and compact structure, and miniaturization.

[0003] There are significant differences between lasers and nitride semiconductor light-emitting diodes.

[0004] Laser is generated by stimulated emission of carriers, with a small spectral half-width and high brightness. The output power of a single laser can be in the W level, while nitride semiconductor light-emitting diodes emit spontaneous radiation, and the output power of a single light-emitting diode is in the mW level.

[0005] The current density of the laser is up to KA / cm 2 , 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] 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. The energy of the induced photon should be equal to the difference in the energy levels of the electron transition, producing the same coherent light as the photon and the induced photon.

[0007] The principles are different: under the action of external voltage, light-emitting diodes produce radiative recombination and light emission when electrons and holes jump to quantum wells or pn junctions, while lasers require that lasing conditions are met before they can be emitted. The carrier inversion distribution in the active area must be met, and the stimulated radiation light oscillates back and forth in the resonant cavity. The propagation in the gain medium amplifies the light, and the threshold condition is met so that the gain is greater than the loss, and finally the laser is output.

[0008] Nitride semiconductor lasers have the following problems:

[0009] The optical waveguide has high absorption loss. Intrinsic carbon impurities in p-type semiconductors will compensate for acceptors and destroy the p-type. The ionization rate of p-type doping is low, and a large amount of unionized Mg acceptor impurities will lead to increased internal optical losses. In addition, the refractive index dispersion of the laser and the high concentration carrier concentration fluctuations affect the refractive index of the active layer. The confinement factor decreases with increasing wavelength, resulting in a decrease in the mode gain of the laser.

[0010] Laser lightwave patterns can be categorized as transverse modes and longitudinal and transverse modes. The transverse mode intensity distribution within the cross-section perpendicular to the optical axis is determined by the waveguide structure of the semiconductor laser. If the transverse mode is complex and unstable, the output light will have poor coherence. The longitudinal mode exhibits a standing wave distribution in the propagation direction of the resonant cavity. If many longitudinal modes are simultaneously emitted or there are inter-mode variations, high temporal coherence cannot be achieved. Summary of the Invention

[0011] The present invention provides a semiconductor laser element. The specific electron effective mass distribution and refractive index distribution of the dark exciton resonance layer enhance the strong coupling effect between dark excitons and photons, reduce the effective mass of exciton polaritons and increase the group velocity, enhance the dipole resonance intensity and the nonlinear effect of exciton polaritons, enhance the coherence of dark exciton polaritons, reduce the laser mode number, increase the photon degeneracy, improve the output laser coherence, and improve the beam quality factor.

[0012] The present invention provides a semiconductor laser element, which comprises, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer, wherein a dark exciton resonance layer is provided between the lower confinement layer and the lower waveguide layer.

[0013] The dark exciton resonance layer is any one 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, or any combination thereof;

[0014] The dark exciton resonance layer includes a first dark exciton resonance layer, a second dark exciton resonance layer and a third dark exciton resonance layer.

[0015] Preferably, the spontaneous polarization coefficient distribution of the first dark exciton resonance layer has a first quadrant curve distribution of the function y1=A+B*x / lnx; the spontaneous polarization coefficient distribution of the second dark exciton resonance layer has a linear function distribution; the spontaneous polarization coefficient distribution of the third dark exciton resonance layer has a y2=C+D*xe xCurved distribution.

[0016] Preferably, the spontaneous polarization coefficient of the first dark exciton resonance layer is a, the spontaneous polarization coefficient of the second dark exciton resonance layer is b, and the spontaneous polarization coefficient of the third dark exciton resonance layer is c, wherein: -0.5≤a≤b≤c≤-0.01.

[0017] Preferably, the electron affinity energy distribution of the first dark exciton resonance layer has a curve distribution of function y3=E+F*lnx / x; the electron affinity energy distribution of the second dark exciton resonance layer has a linear function distribution; and the electron affinity energy distribution of the third dark exciton resonance layer has a second four-quadrant curve distribution of y4=G+H*cosx / x.

[0018] Preferably, the electron affinity of the first dark exciton resonance layer is d, the electron affinity of the second dark exciton resonance layer is e, and the electron affinity of the third dark exciton resonance layer is f, wherein: 0.1≤e≤d≤f≤10.

[0019] Preferably, the electron effective mass distribution of the first dark exciton resonance layer has a function y5=J+K*lnx / e x Curve distribution; the electron effective mass distribution of the second dark exciton resonance layer has a linear function distribution; the electron effective mass distribution of the third dark exciton resonance layer has y6=L+M*e x / x 2 Second quadrant curve distribution.

[0020] Preferably, the electron effective mass of the first dark exciton resonance layer is g, the electron effective mass of the second dark exciton resonance layer is h, and the electron effective mass of the third dark exciton resonance layer is i, wherein: 0.01≤i≤h≤g≤5.

[0021] Preferably, the refractive index coefficient distribution of the first dark exciton resonance layer has a function y7=N+P*sinx / x 2 The first quadrant curve distribution; the refractive index coefficient distribution of the second dark exciton resonance layer has a linear function distribution; the refractive index coefficient distribution of the third dark exciton resonance layer has y8=Q+R*x 2 e x Curved distribution.

[0022] Preferably, the refractive index coefficient distribution of the first dark exciton resonance layer is j, the refractive index coefficient distribution of the second dark exciton resonance layer is k, and the refractive index coefficient distribution of the third dark exciton resonance layer is l, wherein: 1≤j≤k≤l≤10.

[0023] Preferably, the active layer is a periodic structure composed of a well layer and a barrier layer, the number of periods is 3 ≥ m ≥ 1, and the well layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN A method of manufacturing a silicon-based substrate having a thickness of 10 to 100 angstroms, wherein the barrier layer is any one 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, or any combination thereof, with a thickness of 10 to 150 angstroms.

[0024] Preferably, the lower confinement layer, the lower waveguide layer, the upper waveguide layer and the upper confinement layer are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN.

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

[0026] Compared with the prior art, the semiconductor laser element provided by the embodiment of the present invention has the following beneficial effects:

[0027] 1. The spontaneous polarization coefficient distribution of the waveguide layer under the excitation of the dark exciton resonance layer induces the dark excitons to generate out-of-plane transition dipoles, thereby enhancing the dark exciton resonance and laser emission, and improving the photoelectric conversion efficiency coupled with the dark excitons, thereby improving the luminous power and slope efficiency of the laser.

[0028] 2. The specific electron affinity energy distribution of the dark exciton resonance layer induces anti-Stokes laser radiation, balances dispersion and self-phase modulation, balances laser gain and uniform loss, reduces group velocity dispersion and high-order dispersion of the waveguide layer, reduces optical waveguide absorption loss and internal optical loss, and improves laser power and slope efficiency.

[0029] 3. The specific electron effective mass distribution and refractive index distribution of the dark exciton resonance layer enhance the strong coupling effect between dark excitons and photons, reduce the effective mass of exciton polaritons and increase the group velocity, enhance the dipole resonance intensity and the nonlinear effect of exciton polaritons, enhance the coherence of dark exciton polaritons, reduce the laser mode number, increase the photon degeneracy, improve the output laser coherence, and improve the beam quality factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic structural diagram of a semiconductor laser element provided by the present invention.

[0031] Figure 2 This is a SIMS secondary ion mass spectrum of a semiconductor laser element provided by the present invention.

[0032] In the figure, markings are as follows: 100: substrate; 101: lower confinement layer; 102: lower waveguide layer; 103: active layer; 104: upper waveguide layer, 105: upper confinement layer, 106: dark exciton resonance layer, 106a: first dark exciton resonance layer, 106b: second dark exciton resonance layer, 106c: third dark exciton resonance layer. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] In order to solve the above problems, a semiconductor laser element provided in an embodiment of the present application will be introduced and explained in detail through the following specific embodiments.

[0035] Reference Figure 1-2 The present invention provides a semiconductor laser element, which comprises, from bottom to top, a substrate 100, a lower confinement layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, and an upper confinement layer 105. A dark exciton resonance layer 106 is provided between the lower confinement layer 101 and the lower waveguide layer 102. The dark exciton resonance layer 106 is made of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGa Any one or any combination of InP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond; the dark exciton resonance layer 106 includes a first dark exciton resonance layer 106a, a second dark exciton resonance layer 106b, and a third dark exciton resonance layer 106c.

[0036] The spontaneous polarization coefficient distribution of the first dark exciton resonance layer 106a has a first quadrant curve distribution of the function y1=A+B*x / lnx; the spontaneous polarization coefficient distribution of the second dark exciton resonance layer 106b has a linear function distribution; the spontaneous polarization coefficient distribution of the third dark exciton resonance layer 106c has a y2=C+D*xe x curve distribution; the spontaneous polarization coefficient of the first dark exciton resonance layer 106a is a, the spontaneous polarization coefficient of the second dark exciton resonance layer 106b is b, and the spontaneous polarization coefficient of the third dark exciton resonance layer 106c is c, wherein: -0.5≤a≤b≤c≤-0.01.

[0037] The electron affinity distribution of the first dark exciton resonance layer 106a has a curve distribution of the function y3=E+F*lnx / x; the electron affinity distribution of the second dark exciton resonance layer 106b has a linear function distribution; the electron affinity distribution of the third dark exciton resonance layer 106c has a second four-quadrant curve distribution of y4=G+H*cosx / x; the electron affinity of the first dark exciton resonance layer 106a is d, the electron affinity of the second dark exciton resonance layer 106b is e, and the electron affinity of the third dark exciton resonance layer 106c is f, wherein: 0.1≤e≤d≤f≤10.

[0038] The electron effective mass distribution of the first dark exciton resonance layer 106a has a function y5=J+K*lnx / e xCurve distribution; the electron effective mass distribution of the second dark exciton resonance layer 106b has a linear function distribution; the electron effective mass distribution of the third dark exciton resonance layer 106c has y6=L+M*e x / x 2 The second quadrant curve distribution: The electron effective mass of the first dark exciton resonance layer 106a is g, the electron effective mass of the second dark exciton resonance layer 106b is h, and the electron effective mass of the third dark exciton resonance layer 106c is i, wherein: 0.01≤i≤h≤g≤5.

[0039] The refractive index coefficient distribution of the first dark exciton resonance layer 106a has a function y7=N+P*sinx / x 2 The first quadrant curve distribution; the refractive index coefficient distribution of the second dark exciton resonance layer 106b has a linear function distribution; the refractive index coefficient distribution of the third dark exciton resonance layer 106c has y8=Q+R*x 2 e x The refractive index coefficient of the first dark exciton resonance layer 106a is distributed as j, the refractive index coefficient of the second dark exciton resonance layer 106b is distributed as k, and the refractive index coefficient of the third dark exciton resonance layer 106c is distributed as l, wherein: 1≤j≤k≤l≤10.

[0040] The following table specifically shows a comparison of data between the conventional laser and the laser of the present invention.

[0041]

[0042] In the present invention, the active layer 103 is a periodic structure composed of a well layer and a barrier layer, the period number is 3 ≥ m ≥ 1, and the well layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN. The barrier layer is any one 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 150 angstroms.

[0043] In the present invention, the lower confinement layer 101, the lower waveguide layer 102, the upper waveguide layer 104, and the upper confinement layer 105 are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN.

[0044] In the present invention, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, sapphire / SiN x Composite substrate, sapphire / SiO2 / SiN x Any one of a composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, and a LiAlO2 / LiGaO2 composite substrate.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A semiconductor laser element, comprising, from bottom to top, a substrate (100), a lower confinement layer (101), a lower waveguide layer (102), an active layer (103), an upper waveguide layer (104), and an upper confinement layer (105), characterized in that: A dark exciton resonance layer (106) is provided between the lower confinement layer (101) and the lower waveguide layer (102). The dark exciton resonance layer (106) is any one 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, or any combination thereof; The dark exciton resonance layer (106) comprises a first dark exciton resonance layer (106a), a second dark exciton resonance layer (106b) and a third dark exciton resonance layer (106c).

2. The semiconductor laser element according to claim 1, wherein: The spontaneous polarization coefficient distribution of the first dark exciton resonance layer (106a) has a first quadrant curve distribution of the function y1=A+B*x / lnx; the spontaneous polarization coefficient distribution of the second dark exciton resonance layer (106b) has a linear function distribution; the spontaneous polarization coefficient distribution of the third dark exciton resonance layer (106c) has a first quadrant curve distribution of the function y1=A+B*x / lnx; x Curved distribution.

3. The semiconductor laser element according to claim 2, characterized in that: The spontaneous polarization coefficient of the first dark exciton resonance layer (106a) is a, the spontaneous polarization coefficient of the second dark exciton resonance layer (106b) is b, and the spontaneous polarization coefficient of the third dark exciton resonance layer (106c) is c, wherein: -0.5≤a≤b≤c≤-0.

01.

4. The semiconductor laser element according to claim 1, wherein: The electron affinity energy distribution of the first dark exciton resonance layer (106a) has a function y3=E+F*lnx / x curve distribution; the electron affinity energy distribution of the second dark exciton resonance layer (106b) has a linear function distribution; and the electron affinity energy distribution of the third dark exciton resonance layer (106c) has a second four-quadrant curve distribution of y4=G+H*cosx / x.

5. The semiconductor laser element according to claim 4, characterized in that: The electron affinity of the first dark exciton resonance layer (106a) is d, the electron affinity of the second dark exciton resonance layer (106b) is e, and the electron affinity of the third dark exciton resonance layer (106c) is f, wherein: 0.1≤e≤d≤f≤10.

6. The semiconductor laser element according to claim 1, characterized in that: The electron effective mass distribution of the first dark exciton resonance layer (106a) has a function y5=J+K*lnx / e x curve distribution; the electron effective mass distribution of the second dark exciton resonance layer (106b) has a linear function distribution; the electron effective mass distribution of the third dark exciton resonance layer (106c) has y6=L+M*e x / x 2 Second quadrant curve distribution.

7. The semiconductor laser element according to claim 6, characterized in that: The electron effective mass of the first dark exciton resonance layer (106a) is g, the electron effective mass of the second dark exciton resonance layer (106b) is h, and the electron effective mass of the third dark exciton resonance layer (106c) is i, wherein: 0.01≤i≤h≤g≤5.

8. The semiconductor laser element according to claim 1, wherein: The refractive index coefficient distribution of the first dark exciton resonance layer (106a) has a function y7=N+P*sinx / x 2 The first quadrant curve distribution; the refractive index coefficient distribution of the second dark exciton resonance layer (106b) has a linear function distribution; the refractive index coefficient distribution of the third dark exciton resonance layer (106c) has y8=Q+R*x 2 e x Curved distribution.

9. The semiconductor laser element according to claim 8, characterized in that: The refractive index coefficient distribution of the first dark exciton resonance layer (106a) is j, the refractive index coefficient distribution of the second dark exciton resonance layer (106b) is k, and the refractive index coefficient distribution of the third dark exciton resonance layer (106c) is l, wherein: 1≤j≤k≤l≤10.

10. The semiconductor laser element according to claim 1, characterized in that: The active layer (103) is a periodic structure composed of a well layer and a barrier layer, the number of periods is 3≥m≥1, and the well layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN A method of manufacturing a silicon-based substrate having a thickness of 10 to 100 angstroms, wherein the barrier layer is any one 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, or any combination thereof, with a thickness of 10 to 150 angstroms.

11. The semiconductor laser element according to claim 1, characterized in that: The lower confinement layer (101), the lower waveguide layer (102), the upper waveguide layer (104), and the upper confinement layer (105) are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN.

12. The semiconductor laser element according to claim 1, characterized in that: The substrate (100) includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, sapphire / SiN x Composite substrate, sapphire / SiO2 / SiN x Any one of a composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, and a LiAlO2 / LiGaO2 composite substrate.

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