A semiconductor laser element provided with a stimulated Brillouin scattering layer

Abstract

The present invention provides a semiconductor laser device provided with a stimulated Brillouin scattering layer, relating to the technical field of semiconductor optoelectronic devices. It sequentially includes a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, and an upper confinement layer from bottom to top. The upper confinement layer and the lower confinement layer are provided with stimulated Brillouin scattering layers; the stimulated Brillouin scattering layer is formed by designing the Mg / C concentration ratio, Mg / O concentration ratio, Mg / H concentration ratio, and Al concentration difference through the structure of the upper confinement layer and the lower confinement layer, so as to limit the propagation of photons and phonons, confine the phonons in the Brillouin zone in the laser, suppress phonon leakage, utilize phonons to manipulate the stimulated Brillouin scattering to reflect the spectrum of a specific wavelength, improve the Brillouin scattering gain coefficient, reduce the absorption loss and internal optical loss of the optical waveguide, improve the laser power and slope efficiency. At the same time, reduce the laser mode number, improve the photon degeneracy, and improve the coherence of the output laser.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor optoelectronic devices, and more particularly, to a semiconductor laser device provided with a stimulated Brillouin scattering 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. 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 / cm², 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 effects, and more serious electron-hole mismatch, leading to a more serious efficiency droop effect; 3) Light-emitting diodes undergo spontaneous transition radiation, which is incoherent light that transitions from a high energy level to a low energy level without external influence, while lasers are stimulated transition radiation, and the induced photon energy should be equal to the energy difference between 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 quantum wells or p-n junctions under the action of an external voltage, while lasers can only lasing when the lasing conditions are met. It must satisfy the condition of carrier population inversion 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. Nitride semiconductor lasers have the following problems: 1. The absorption loss of the optical waveguide is high. Intrinsic carbon impurities in the p-type semiconductor will compensate for acceptors, destroy the p-type, etc. The ionization rate of p-type doping is low, and a large number of un-ionized Mg acceptor impurities will cause an increase in internal optical loss. Moreover, the refractive index dispersion of the laser, the high-concentration carrier concentration fluctuation affects the refractive index of the active layer, and the confinement factor decreases with the increase of wavelength, resulting in a decrease in the mode gain of the laser; 2. The mode of the laser light wave can be divided into transverse mode and longitudinal mode; the transverse mode light intensity distribution in 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 coherence of the output light is poor; the longitudinal mode is a standing wave distribution in the propagation direction of the resonant cavity. If many longitudinal modes lase simultaneously or there are mode changes, high temporal coherence cannot be obtained. Summary of the Invention

[0003] The object of the present invention is to provide a semiconductor laser element provided with a stimulated Brillouin scattering layer, which solves the problems existing in the prior art.

[0004] A semiconductor laser element provided with a stimulated Brillouin scattering layer includes, from bottom to top in sequence, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, and an upper confinement layer. The lower confinement layer (101) and the upper confinement layer (106) form a stimulated Brillouin scattering layer (107).

[0005] As a preferred technical solution of the present invention, the Mg / C concentration ratio of the upper confinement layer of the stimulated Brillouin scattering layer tested by a SIMS secondary ion mass spectrometer is greater than or equal to the Si / C concentration ratio of the lower confinement layer.

[0006] As a preferred technical solution of the present invention, the Mg / O concentration ratio of the upper confinement layer of the stimulated Brillouin scattering layer tested by a SIMS secondary ion mass spectrometer is greater than or equal to the Si / O concentration ratio of the lower confinement layer.

[0007] As a preferred technical solution of the present invention, the Mg / H concentration ratio of the upper confinement layer of the stimulated Brillouin scattering layer tested by a SIMS secondary ion mass spectrometer is less than or equal to the Si / H concentration ratio of the lower confinement layer.

[0008] As a preferred technical solution of the present invention, the Al concentration of the upper confinement layer of the stimulated Brillouin scattering layer tested by a SIMS secondary ion mass spectrometer is less than or equal to the Al concentration of the lower confinement layer.

[0009] As a preferred technical solution of the present invention, the stimulated Brillouin scattering layer is formed by designing the structure of the upper confinement layer and the lower confinement layer to have differences in Mg / C concentration ratio, Mg / O concentration ratio, Mg / H concentration ratio, and Al concentration, so as to limit the propagation of photons and phonons, confine the phonons in the Brillouin zone in the laser, suppress phonon leakage, utilize phonons to manipulate the stimulated Brillouin scattering to reflect the spectrum of a specific wavelength, enhance the Brillouin scattering gain coefficient, reduce the absorption loss and internal optical loss of the optical waveguide, enhance the laser power and slope efficiency. At the same time, reduce the laser mode number, enhance the photon degeneracy, and enhance the coherence of the output laser.

[0010] As a preferred technical solution of the present invention, the Mg / C, Mg / O, and Mg / H concentration ratios of the upper confinement layer of the stimulated Brillouin scattering layer are all 10 to 500, and the Si / C, Si / O, and Si / H concentration ratios of the lower confinement layer are all 5 to 100.

[0011] As a preferred technical solution of the present invention, the lower confinement layer, the lower waveguide layer, the active layer, the upper waveguide layer, the electron blocking layer, and the upper confinement layer include GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2 O 3 Any one or any multiple combinations of BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP.

[0012] As a preferred technical solution of the present invention, the substrate includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiNx, sapphire / SiO2 / SiNx composite substrate, magnesium aluminate spinel MgAl 2 O 4 O, MgO, ZnO, ZrB 2 O 2 and LiGaO 2 Any one of the composite substrates.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] In the solution of the present invention:

[0015] The upper confinement layer and the lower confinement layer are provided with a stimulated Brillouin scattering layer; the stimulated Brillouin scattering layer is formed by designing the Mg / C concentration ratio, Mg / O concentration ratio, Mg / H concentration ratio, and Al concentration difference between the upper confinement layer and the lower confinement layer, so as to limit the propagation of photons and phonons, confine the phonons in the Brillouin zone in the laser, suppress phonon leakage, use phonons to manipulate the stimulated Brillouin scattering to reflect the spectrum of a specific wavelength, improve the Brillouin scattering gain coefficient, reduce the absorption loss and internal optical loss of the optical waveguide, improve the laser power and slope efficiency. At the same time, reduce the laser mode number, improve the photon degeneracy, and improve the coherence of the output laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of a semiconductor laser element provided with a stimulated Brillouin scattering layer according to the present invention.

[0017] Figure 2 It is a SIMS secondary ion mass spectrometry schematic diagram of a semiconductor laser element provided with a stimulated Brillouin scattering layer according to the present invention.

[0018] The labels in the figure are:

[0019] 100: Substrate; 101: Lower confinement layer; 102: Lower waveguide layer; 103: Active layer; 104: Upper waveguide layer, 105: Electron blocking layer, 106: Upper confinement layer, 107: Stimulated Brillouin scattering layer. DETAILED DESCRIPTION OF THE INVENTION

[0020] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0021] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0022] It should be noted that, without conflict, the embodiments in the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0023] Please refer to Figure 1-2 , this embodiment provides a technical solution: a semiconductor laser element provided with a stimulated Brillouin scattering layer, which sequentially includes a substrate 100, a lower confinement layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, an electron blocking layer 105, and an upper confinement layer 106 from bottom to top. It is characterized in that: a stimulated Brillouin scattering layer 107 is provided between the lower confinement layer 101 and the upper confinement layer 106; the Mg / C concentration ratio of the upper confinement layer of the stimulated Brillouin scattering layer 107 tested by a SIMS secondary ion mass spectrometer is greater than or equal to the Si / C concentration ratio of the lower confinement layer; the Mg / O concentration ratio of the upper confinement layer of the stimulated Brillouin scattering layer 107 tested by a SIMS secondary ion mass spectrometer is greater than or equal to the Si / O concentration ratio of the lower confinement layer; the Mg / H concentration ratio of the upper confinement layer of the stimulated Brillouin scattering layer 107 tested by a SIMS secondary ion mass spectrometer is less than or equal to the Si / H concentration ratio of the lower confinement layer; the Al concentration of the upper confinement layer of the stimulated Brillouin scattering layer 107 tested by a SIMS secondary ion mass spectrometer is less than or equal to the Al concentration of the lower confinement layer; the stimulated Brillouin scattering layer 107 is formed by designing the Mg / C concentration ratio, Mg / O concentration ratio, Mg / H concentration ratio and Al concentration difference between the upper confinement layer and the lower confinement layer, so as to limit the propagation of photons and phonons, confine the phonons in the Brillouin zone in the laser, suppress phonon leakage, use phonons to manipulate the stimulated Brillouin scattering to reflect the spectrum of a specific wavelength, enhance the Brillouin scattering gain coefficient, reduce the optical waveguide absorption loss and internal optical loss, enhance the laser power and slope efficiency. At the same time, reduce the laser mode number, enhance the photon degeneracy, and enhance the coherence of the output laser; the Mg / C, Mg / O and Mg / H concentration ratios of the upper confinement layer of the stimulated Brillouin scattering layer 107 are all 10 to 500, and the Si / C, Si / O and Si / H concentration ratios of the lower confinement layer are all 5 to 100;

[0024] The lower confinement layer 101, lower waveguide layer 102, active layer 103, upper waveguide layer 104, electron blocking layer 105, and upper confinement layer 106 include any one or any multi-element combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga 2 O 3 , BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP.

[0025] The substrate 100 includes any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiNx, sapphire / SiO2 / SiNx composite substrate, magnesium aluminate spinel MgAl 2 O 4 , MgO, ZnO, ZrB 2 , LiAlO 2 and LiGaO 2 composite substrate.

[0026] Compared with the prior art, in the present invention: the upper confinement layer and the lower confinement layer are provided with a stimulated Brillouin scattering layer; the stimulated Brillouin scattering layer is formed by designing the Mg / C concentration ratio, Mg / O concentration ratio, Mg / H concentration ratio and Al concentration difference through the structure of the upper confinement layer and the lower confinement layer, so as to limit the propagation of photons and phonons, confine the phonons in the Brillouin zone in the laser, suppress phonon leakage, utilize phonons to manipulate the stimulated Brillouin scattering to reflect the spectrum of a specific wavelength, improve the stimulated Brillouin scattering gain coefficient, reduce the optical waveguide absorption loss and internal optical loss, improve the laser power and slope efficiency. At the same time, reduce the laser mode number, improve the photon degeneracy, and improve the coherence of the output laser.

[0027] The above embodiments are only used to illustrate the present invention and do not limit the technical solutions described in the present invention. Although the present specification has described the present invention in detail with reference to the above respective embodiments, the present invention is not limited to the above specific embodiments. Therefore, any modification or equivalent replacement of the present invention; and all technical solutions and their improvements that do not depart from the spirit and scope of the invention are covered by the scope of the claims of the present invention.

Claims

1. A semiconductor laser device provided with a stimulated Brillouin scattering layer, which sequentially includes a substrate (100), a lower confinement layer (101), a lower waveguide layer (102), an active layer (103), an upper waveguide layer (104), an electron blocking layer (105), and an upper confinement layer (106) from bottom to top. It is characterized in that: The lower confinement layer (101) and the upper confinement layer (106) form a stimulated Brillouin scattering layer (107). The stimulated Brillouin scattering layer (107) is formed by designing the Mg / C concentration ratio, Mg / O concentration ratio, Mg / H concentration ratio, and Al concentration difference between the upper confinement layer (106) and the lower confinement layer (101), so as to limit the propagation of photons and phonons, confine the phonons in the Brillouin zone in the laser, suppress phonon leakage, manipulate the stimulated Brillouin scattering to reflect the spectrum of a specific wavelength by using phonons, enhance the Brillouin scattering gain coefficient, reduce the absorption loss and internal optical loss of the optical waveguide, enhance the laser power and slope efficiency. At the same time, reduce the laser mode number, enhance the photon degeneracy, and enhance the coherence of the output laser.

2. A semiconductor laser device provided with a stimulated Brillouin scattering layer as described in claim 1, wherein the Mg / C concentration ratio of the upper confinement layer of the stimulated Brillouin scattering layer (107) tested by a SIMS secondary ion mass spectrometer is greater than or equal to the Si / C concentration ratio of the lower confinement layer.

3. A semiconductor laser device provided with a stimulated Brillouin scattering layer as described in claim 1, It is characterized in that, The Mg / O concentration ratio of the upper confinement layer (106) of the stimulated Brillouin scattering layer (107) tested by a SIMS secondary ion mass spectrometer is greater than or equal to the Si / O concentration ratio of the lower confinement layer (101).

4. A semiconductor laser device provided with a stimulated Brillouin scattering layer as described in claim 1, It is characterized in that, The Mg / H concentration ratio of the upper confinement layer (106) of the stimulated Brillouin scattering layer (107) tested by a SIMS secondary ion mass spectrometer is less than or equal to the Si / H concentration ratio of the lower confinement layer (101).

5. A semiconductor laser device provided with a stimulated Brillouin scattering layer as described in claim 1, It is characterized in that, The Al concentration of the upper confinement layer (106) of the stimulated Brillouin scattering layer (107) tested by a SIMS secondary ion mass spectrometer is less than or equal to the Al concentration of the lower confinement layer (101).

6. A semiconductor laser device provided with a stimulated Brillouin scattering layer as described in claim 2, It is characterized in that, The Mg / C, Mg / O, and Mg / H concentration ratios of the upper confinement layer (106) of the stimulated Brillouin scattering layer (107) are all 10 - 500, and the Si / C, Si / O, and Si / H concentration ratios of the lower confinement layer (101) are all 5 - 100.

7. A semiconductor laser device provided with a stimulated Brillouin scattering layer as described in claim 1, It is characterized in that, The lower confinement layer (101), lower waveguide layer (102), active layer (103), upper waveguide layer (104), electron blocking layer (105), and upper confinement layer (106) include any one or any multiple combinations of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga 2 O 3 , BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP.

8. A semiconductor laser device provided with a stimulated Brillouin scattering layer as described in claim 1, It is characterized in that, The substrate (100) includes any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiNx, sapphire / SiO2 / SiNx composite substrate, magnesium aluminate spinel MgAl 2 O 4 , MgO, ZnO, ZrB 2 , LiAlO 2 and LiGaO 2 composite substrate.

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