Semiconductor laser, laser light source, and laser projection apparatus

Abstract

The embodiment of the utility model provides a semiconductor laser, a laser light source and laser projection equipment, and relates to the technical field of laser projection. The semiconductor laser comprises an N-type substrate, an N-type limiting layer, an N-type waveguide layer, an N-side barrier layer, a quantum well layer, a P-side barrier layer, a P-type waveguide layer and a P-type limiting layer, the N-type limiting layer and the P-type limiting layer form an asymmetric limiting layer structure, and the N-type waveguide layer and the P-type waveguide layer form an asymmetric waveguide layer structure; and the thickness of the N-side barrier layer is different from that of the P-side barrier layer. The embodiment of the utility model is used for improving the performance of the semiconductor laser.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of laser projection technology, and more specifically, to a semiconductor laser, a laser light source, and a laser projection device. Background Art

[0002] Laser display technology is known as a "revolution in the history of human vision" because of its advantages such as good monochromaticity, wide color gamut, long life, high brightness and low power consumption. Compared with the LED light source and blue laser excited phosphor light source in traditional projection TVs, laser light source is a very efficient light source that can make up for the low electro-optical efficiency of LED light source, low conversion efficiency of blue laser excited phosphor, poor heat dissipation characteristics and difficulty in application to large-size projection. It is also the only display technology that fully meets the international standard BT.2020 for ultra-high-definition display.

[0003] Semiconductor lasers are used as laser light sources in laser display technology due to their advantages such as wide output band coverage, high output power, small size and long life. With the continuous development of laser display technology, higher requirements are placed on the performance of semiconductor lasers (such as output power, electro-optical conversion efficiency and beam quality). At present, semiconductor lasers use a single asymmetric epitaxial structure (asymmetric waveguide layer structure) or a double asymmetric epitaxial structure (asymmetric waveguide layer structure and asymmetric confinement layer structure) to improve their performance, but the performance improvement is limited and still cannot meet user requirements. Utility Model Content

[0004] The exemplary embodiments of the present application provide a semiconductor laser, a laser light source, and a laser projection device for improving the performance of the semiconductor laser.

[0005] The technical solutions provided by the embodiments of this application are as follows:

[0006] In a first aspect, an embodiment of the present application provides a semiconductor laser, comprising an N-type substrate and an N-type confinement layer, an N-type waveguide layer, an N-side barrier layer, a quantum well layer, a P-side barrier layer, a P-type waveguide layer and a P-type confinement layer sequentially stacked on the N-type substrate;

[0007] The N-type confinement layer and the P-type confinement layer form an asymmetric confinement layer structure, and the N-type waveguide layer and the P-type waveguide layer form an asymmetric waveguide layer structure;

[0008] The N-side barrier layer and the P-side barrier layer have different thicknesses.

[0009] In a second aspect, an embodiment of the present application provides a laser light source, including a base plate, a tube wall, at least one semiconductor laser as described in the first aspect, and a collimating lens group;

[0010] The tube wall and the semiconductor laser are both located on the bottom plate, and the tube wall is arranged around the semiconductor laser. The collimating lens group is used for collimating the laser emitted by the semiconductor laser.

[0011] In a third aspect, an embodiment of the present application provides a laser projection device, including: a display control component, a laser light source driving component, the laser light source as described in the second aspect, a light valve, and a lens;

[0012] The display control component is connected to the laser light source driving component and the light valve respectively, and the laser light source driving component is also connected to the laser light source.

[0013] It can be seen from the above technical solutions that the semiconductor laser, laser light source and laser projection equipment provided by the embodiments of the present application, the N-type confinement layer and the P-type confinement layer constitute an asymmetric confinement layer structure, and the N-type waveguide layer and the P-type waveguide layer constitute an asymmetric waveguide layer structure. On the basis of adopting the above-mentioned dual asymmetric epitaxial structure, the thickness of the N-side barrier layer and the P-side barrier layer are further designed to be different to form an asymmetric barrier layer structure, thereby obtaining a semiconductor laser with a multi-asymmetric epitaxial structure. In this way, under the condition of maintaining the low series resistance, low optical loss and low carrier leakage of the semiconductor laser with a dual asymmetric epitaxial structure, by designing the thickness of the N-side barrier layer and the P-side barrier layer to be different, the threshold current of the semiconductor laser can be reduced or the divergence angle of the vertical far field can be reduced, thereby improving the electro-optical conversion efficiency or beam quality of the semiconductor laser, thereby further improving the performance of the semiconductor laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the implementation methods in the embodiments of the present application or the related technologies, the following is a brief introduction to the drawings required for use in the embodiments or the related technology descriptions. Obviously, the drawings described below are some embodiments of the present application, and a person skilled in the art can also obtain other drawings based on these drawings.

[0015] Figure 1 A schematic diagram showing the distribution of the light field and refractive index of a semiconductor laser with an asymmetric waveguide layer structure in an epitaxial structure in the related art is shown;

[0016] Figure 2 A schematic diagram showing the distribution of the optical field and refractive index of a semiconductor laser with a double asymmetric epitaxial structure in the related art is shown;

[0017] Figure 3 A schematic diagram of the structure of a semiconductor laser in some embodiments is shown;

[0018] Figure 4A schematic diagram showing the distribution of the optical field and refractive index of a semiconductor laser in an epitaxial structure in some embodiments is shown;

[0019] Figure 5 A schematic diagram showing optical power-current curves of semiconductor lasers with different epitaxial structures in some embodiments;

[0020] Figure 6 A schematic diagram showing a photoelectric conversion efficiency-current curve of semiconductor lasers with different epitaxial structures in some embodiments;

[0021] Figure 7 A schematic diagram showing the structure of another semiconductor laser in some embodiments is shown;

[0022] Figure 8 A schematic diagram of the structure of a laser light source in some embodiments is shown;

[0023] Fig. 9 A schematic diagram showing the structure of another laser light source in some embodiments is shown;

[0024] Fig.10 A structural block diagram of a laser projection device in some embodiments is shown. DETAILED DESCRIPTION

[0025] In order to make the purpose and implementation method of the present application clearer, the exemplary implementation method of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0026] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their common and usual meanings.

[0027] The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0028] Light absorption in semiconductor lasers is proportional to the doping concentration of the doped region, and the loss of photons absorbed by holes in P-type materials is greater than the loss of photons absorbed by electrons in N-type materials. In a symmetrical waveguide structure, light absorption by carriers in the P-type highly doped region is the main reason for the formation of internal losses and the reduction of electro-optical conversion efficiency. In related technologies, an asymmetric waveguide layer structure is used to transform the light field distribution of a conventional symmetrical waveguide layer structure into an asymmetric light field distribution, so that the light field is distributed as much as possible in the N-type region, reducing the overlap ratio of the light field and the P-type region of the semiconductor laser, thereby minimizing the light loss caused by free carrier absorption and scattering in the P-type region to obtain a higher electro-optical conversion efficiency. Figure 1 The figure shows the distribution of the light field (Wave Intensity) and refractive index (Real Index) of a semiconductor laser with an asymmetric waveguide layer structure in the epitaxial structure. The horizontal axis Distance represents the distance of the epitaxial structure of the semiconductor laser along the lateral direction. The serial numbers represent the film layers of the epitaxial structure, including: ① buffer layer; ② N-type confinement layer; ③ N-type waveguide layer; ④ N-side barrier layer; ⑤ quantum well layer; ⑥ P-side barrier layer; ⑦ P-type waveguide layer; ⑧ P-type confinement layer; ⑨ Ohmic contact layer. The N-side barrier layer, quantum well layer and P-side barrier layer constitute the active region. Figure 1 It can be seen that the use of an asymmetric waveguide layer structure can cause the light field to shift toward the N-type region, but there is still a large overlap between the light field and the P-type confinement layer, resulting in problems of carrier leakage and light loss. In response to this, the related technology uses a dual asymmetric epitaxial structure of an asymmetric confinement layer structure and an asymmetric waveguide layer structure to cause the light field to continue to shift toward the N-type region, reduce the overlap between the light field and the P-type confinement layer, and thereby reduce series resistance, carrier leakage, and light loss. Figure 2 The distribution of the light field (Wave Intensity) and refractive index (Real Index) of the semiconductor laser with a dual asymmetric epitaxial structure in the epitaxial structure is shown. Figure 2 It can be seen that compared with Figure 1 , the spot energy distributed in the active area is reduced, the light confinement is weakened, resulting in a decrease in the optical confinement factor, that is, a decrease in the modal gain, which in turn leads to an increase in the threshold current of the semiconductor laser and a decrease in the electro-optical conversion efficiency. At the same time, the divergence angle of the semiconductor laser with a double asymmetric epitaxial structure in the vertical far field is not ideal, and it is impossible to output a high-quality beam, which leads to higher requirements for the collimator.

[0029] In response to the above technical problems, the inventors have found that, based on the above-mentioned semiconductor laser with a dual asymmetric epitaxial structure, by setting the thickness of the N-side barrier layer and the P-side barrier layer to be different, the vertical mode expansion (i.e., light field distribution) of the active region and the divergence angle of the vertical far field can be adjusted while maintaining the low series resistance, low optical loss and low carrier leakage of the semiconductor laser with a dual asymmetric epitaxial structure. When the thickness of the N-side barrier layer is greater than the thickness of the P-side barrier layer, the light confinement can be enhanced, the optical confinement factor can be increased, and the electro-optical conversion efficiency of the semiconductor laser can be improved. When the thickness of the N-side barrier layer is less than the thickness of the P-side barrier layer, the divergence angle of the vertical far field can be reduced, and the beam quality can be improved. Based on this, the embodiment of the present application provides a semiconductor laser, Figure 3 FIG. 4 shows a schematic diagram of the structure of a semiconductor laser in some embodiments. Figure 3 As shown, the semiconductor laser includes an N-type substrate 11 and an N-type confinement layer 12, an N-type waveguide layer 13, an N-side barrier layer 14, a quantum well layer 15, a P-side barrier layer 16, a P-type waveguide layer 17 and a P-type confinement layer 18 which are sequentially stacked on the N-type substrate 11;

[0030] The N-type confinement layer 12 and the P-type confinement layer 18 constitute an asymmetric confinement layer structure, and the N-type waveguide layer 13 and the P-type waveguide layer 17 constitute an asymmetric waveguide layer structure;

[0031] The N-side barrier layer 14 and the P-side barrier layer 16 have different thicknesses.

[0032] Among them, the N-type confinement layer 12 and the P-type confinement layer 18 constitute an asymmetric confinement layer structure, which means that the thickness and / or composition of the N-type confinement layer 12 and the P-type confinement layer 18 are different; the N-type waveguide layer 13 and the P-type waveguide layer 17 constitute an asymmetric waveguide layer structure, which means that the thickness and / or composition of the N-type waveguide layer 13 and the P-type waveguide layer 17 are different.

[0033] Specifically, in some embodiments, the thickness δn of the N-side barrier layer 14 is greater than the thickness δp of the P-side barrier layer 16 . Figure 4 The diagram shows the distribution of the optical field and refractive index of the semiconductor laser in the epitaxial structure provided by the embodiment of the present application. Figure 2 and Figure 4 In the embodiment of the present application, by setting the thickness δn of the N-side barrier layer 14 to be greater than the thickness δp of the P-side barrier layer 16, the light field distribution in the active region can be adjusted while maintaining the low series resistance, low optical loss and low carrier leakage of the semiconductor laser with a dual asymmetric epitaxial structure, so that the light spot energy in the active region is increased and the light confinement is enhanced, thereby increasing the optical confinement factor of the active region and improving the modal gain, thereby reducing the threshold current of the semiconductor laser and improving the electro-optical conversion efficiency.

[0034] Table 1 Comparison of optical confinement factors and threshold currents of semiconductor lasers with different epitaxial structures

[0035]

[0036] Figure 5 A schematic diagram showing light power (Lightpower)-current (Current) curves of semiconductor lasers with different epitaxial structures in some embodiments; Figure 6 The following is a schematic diagram of the photoelectric conversion efficiency (WPE)-current (Current) curve of semiconductor lasers with different epitaxial structures in some embodiments. Figure 5 and Figure 6 The optical confinement factor of the semiconductor laser with the MAE-HPLD structure provided in the embodiment of the present application is larger than that of the semiconductor laser with the AW-HPLD and DWE-HPLD structures. The threshold current of the semiconductor laser with the MAE-HPLD structure is significantly lower than that of the semiconductor laser with the AW-HPLD and DWE-HPLD structures. Moreover, when the current is high, there is no power saturation phenomenon (see Figure 5 ), and thus the semiconductor laser with MAE-HPLD structure provided in the embodiment of the present application can significantly improve the electro-optical conversion efficiency (see Figure 6 ).

[0037] Additionally, in some embodiments, Figure 7 FIG. 2 shows a schematic diagram of the structure of another semiconductor laser in some embodiments. Different from the above embodiments, Figure 7 The thickness δn of the N-side barrier layer 14 in the semiconductor laser shown is less than the thickness δp of the P-side barrier layer 16. Compared with the case where the thickness δn of the N-side barrier layer 14 is greater than the thickness δp of the P-side barrier layer 16, the present embodiment sets the thickness δn of the N-side barrier layer 14 to be less than the thickness δp of the P-side barrier layer 16, thereby reducing the optical confinement factor and increasing the threshold current, but reducing the divergence angle of the vertical far field, thereby improving the beam quality and improving the luminous brightness of the semiconductor laser; accordingly, since the divergence angle of the vertical far field is reduced, the requirements for the collimating lens are reduced, and the design difficulty of laser beam collimation is reduced.

[0038] It should be noted that Figure 3Only the main film layers involved in the technical solution of the present application are schematically shown. In some embodiments, the semiconductor laser may also include a buffer layer, an electrode contact layer (such as an ohmic contact layer), an N-side electrode and a P-side electrode, etc. Optionally, when preparing the epitaxial structure, a buffer layer, an N-type confinement layer 12, an N-type waveguide layer 13, an N-side barrier layer 14, a quantum well layer 15, a P-side barrier layer 16, a P-type waveguide layer 17, a P-type confinement layer 18 and an electrode contact layer may be sequentially deposited on an N-type substrate 11 by metal organic chemical vapor deposition (MOCVD). Among them, the N-type confinement layer 12 and the P-type confinement layer 18 are used to improve the carrier confinement capability of the semiconductor laser, thereby improving the utilization rate of the carriers; the N-type waveguide layer 13 and the P-type waveguide layer 17 are used to reduce the waveguide to expand the light spot and reduce the divergence angle of the light beam in the vertical direction. The materials and thicknesses of the buffer layer, N-type confinement layer 12, N-type waveguide layer 13, N-side barrier layer 14, quantum well layer 15, P-side barrier layer 16, P-type waveguide layer 17, P-type confinement layer 18 and electrode contact layer can be set according to actual needs.

[0039] The semiconductor laser provided in the embodiment of the present application is applicable to various types of base semiconductor lasers, including but not limited to GaAs-based, GaN-based and InP-based, which are not limited in the present application. At the same time, the semiconductor laser can be applicable to semiconductor lasers of different colors such as red light semiconductor lasers, green light semiconductor lasers and blue light semiconductor lasers. Taking the red light semiconductor laser as an example, the material of the N-type substrate 11 is GaAs; the material of the buffer layer is GaAs, with a thickness of 0.25 to 0.5 μm; the material of the N-type confinement layer 12 is Al x1 Ga 1-x1 P, with a thickness of 0.9 to 1.1 μm; the material of the N-type waveguide layer 13 is (AI x2 Ga 1-x2 ) y1 In 1-y1 P, with a thickness of 100 to 200 nm; the material of the N-side barrier layer 14 is (AI x4 Ga 1-x4 ) y2 In 1-y2 P, with a thickness of 10 to 200 nm; the material of the quantum well layer 15 is Ga x3 In 1-x3 P, thickness is 7-13nm; the material of P-side barrier layer 16 is (AI x4 Ga 1-x4 ) y2 In 1-y2 P, thickness is 10-100nm; the material of the P-type waveguide layer 17 is (AI x5 Ga 1-x5 ) y3 In 1-y3P, thickness is 100-200nm; the material of the P-type confinement layer 18 is AI x6 Ga 1-x6 P, with a thickness of 0.5-0.7 μm; the electrode contact layer is a highly doped GaAs ohmic contact layer with a thickness of 0.15-0.5 μm. Among them, 0.48≤x1≤0.52, 0.4≤x2≤0.9, 0.4≤y1≤0.6, 0.35≤x3≤0.55, 0.3≤x4≤0.62, 0.4≤y2≤0.6, 0.4≤x5≤0.9, 0.4≤y3≤0.6, 0.48≤x6≤0.52, 0.2≤x7≤0.8.

[0040] In some embodiments, the P-side electrode is a P-type ohmic contact electrode. Specifically, Ti / Pt / Au can be sputtered on the surface of the ohmic contact layer 26 using a magnetron sputtering device to improve the ohmic contact condition, and then annealed to form a P-type ohmic contact electrode. The N-side electrode is an N-type contact electrode.

[0041] In the semiconductor laser provided by the embodiment of the present application, the N-type confinement layer and the P-type confinement layer constitute an asymmetric confinement layer structure, and the N-type waveguide layer and the P-type waveguide layer constitute an asymmetric waveguide layer structure. On the basis of adopting the above-mentioned dual asymmetric epitaxial structure, the thickness of the N-side barrier layer and the P-side barrier layer are further designed to be different to form an asymmetric barrier layer structure, thereby obtaining a semiconductor laser with a multi-asymmetric epitaxial structure. In this way, under the condition of maintaining the low series resistance, low optical loss and low carrier leakage of the semiconductor laser with a dual asymmetric epitaxial structure, by designing the thickness of the N-side barrier layer and the P-side barrier layer to be different, the threshold current of the semiconductor laser can be reduced or the divergence angle of the vertical far field can be reduced, thereby improving the electro-optical conversion efficiency or beam quality of the semiconductor laser, thereby further improving the performance of the semiconductor laser.

[0042] In some embodiments, reference Figure 3, the thickness δn of the N-side barrier layer 14 and the thickness δp of the P-side barrier layer 16 satisfy the following relationship: α=δn / (δn+δp), wherein α is greater than 0.5 and less than 0.8. Since α is equal to the thickness of the N-side barrier layer 14 divided by the sum of the thickness of the N-side barrier layer 14 and the thickness of the P-side barrier layer 16, when α is greater than 0.5, the thickness δn of the N-side barrier layer 14 is greater than the thickness δp of the P-side barrier layer 16, and the electro-optical conversion efficiency of the semiconductor laser can be improved. At the same time, considering that if α is greater than or equal to 0.8, the optical confinement factor will be too large, causing nonlinear effects of the semiconductor laser, such as light filaments and self-focusing effects, thereby affecting the output characteristics of the semiconductor laser. Therefore, by setting α to be less than 0.8, the ratio of the thickness δn of the N-side barrier layer 14 to the thickness δp of the P-side barrier layer 16 is limited to avoid the nonlinear effects of the semiconductor laser caused by the excessive optical confinement factor, thereby ensuring the output characteristics of the semiconductor laser.

[0043] In some embodiments, reference Figure 7 , the thickness δn of the N-side barrier layer 14 and the thickness δp of the P-side barrier layer 16 satisfy the following relationship: α=δn / (δn+δp), where α is greater than 0.3 and less than 0.5. Based on the above analysis, when α is less than 0.5, the thickness δn of the N-side barrier layer 14 is less than the thickness δp of the P-side barrier layer 16, and the divergence angle of the vertical far field of the semiconductor laser can be reduced at this time, thereby improving the beam quality. At the same time, considering that if α is less than or equal to 0.3, the optical confinement factor will be too small, causing the threshold current to increase significantly, greatly reducing the electro-optical conversion efficiency of the semiconductor laser. Therefore, by setting α to be greater than 0.3 to limit the ratio of the thickness δn of the N-side barrier layer 14 to the thickness δp of the P-side barrier layer 16, the divergence angle of the vertical far field of the semiconductor laser can be reduced to improve the beam quality while ensuring that the semiconductor laser has good electro-optical conversion efficiency.

[0044] In some embodiments, the thickness of the P-side barrier layer is 10 nm to 100 nm.

[0045] The thicker the barrier layer, the deeper the potential well can be, thereby more effectively limiting the lateral (vertical) movement of carriers in the quantum well layer. This makes it more difficult for carriers to tunnel out of the barrier layer, thereby increasing the carrier density in the quantum well layer, which is beneficial to improving the gain coefficient. At the same time, a thicker barrier layer will cause more light to be reflected in the quantum well layer without penetrating the barrier, thus increasing the optical confinement factor. In addition, when the thickness of the N-side barrier layer and the thickness of the P-side barrier layer are set based on the above α, the thickness difference between the N-side barrier layer and the P-side barrier layer can be increased by increasing the thickness of the P-side barrier layer. The greater the thickness difference, the more obvious the offset of the light field, thereby making the threshold current more significantly reduced, effectively improving the electro-optical conversion efficiency of the semiconductor laser.

[0046] In some embodiments, the N-side barrier layer and the P-side barrier layer are compositionally graded barrier layers. Specifically, the N-side barrier layer and the P-side barrier layer are made of the same material, but one or more components thereof gradually change in a direction away from the quantum well layer, so that the refractive index of the N-side barrier layer and the P-side barrier layer gradually increases in a direction away from the quantum well layer, thereby adjusting the bandgap width and barrier height of the barrier layer and the quantum well layer to limit carriers.

[0047] In some embodiments, the thickness of the N-type confinement layer is greater than that of the P-type confinement layer, and the thickness of the N-type waveguide layer is greater than that of the P-type waveguide layer. Since the optical absorption of carriers in the P-type high-doped region is the main reason for the formation of internal loss and the reduction of electro-optical conversion efficiency, by reducing the thickness of the P-type confinement layer and the P-type waveguide layer, the optical loss caused by the absorption and scattering of free carriers in the P-type doped region can be minimized, and the series resistance can be reduced, thereby improving the electro-optical conversion efficiency of the semiconductor laser.

[0048] An embodiment of the present application also provides a laser light source, including a base plate, a tube wall, at least one semiconductor laser provided in an embodiment of the present application, and a collimating lens group; the tube wall and the semiconductor laser are both located on the base plate, and the tube wall is arranged around the semiconductor laser, and the collimating lens group is used to collimate the laser emitted by the semiconductor laser.

[0049] In some embodiments, the laser light source may be a top-emitting laser light source. Figure 8 As shown, the laser light source includes: a bottom plate 1, a tube wall 2, at least one semiconductor laser 3, at least one reflection prism 4, a heat sink 5, a transparent sealing glass 6 and a collimator lens group 7. Among them, the semiconductor laser 3 is welded on the heat sink 5, the tube wall 2, the semiconductor laser 3 and the reflection prism 4 are all fixed on the bottom plate 1, the semiconductor laser 3 and the reflection prism 4 are surrounded by the tube wall 2, the transparent sealing glass 6 is sealed on the tube wall 2, and the collimator lens group 7 covers the transparent sealing glass 6. The reflection prism 4 is arranged one by one with the semiconductor laser 3, and the reflection prism 4 is used to reflect the laser emitted by the semiconductor laser 3 to the collimator lens group 7. The laser emitted by the semiconductor laser 3 is reflected in the direction away from the bottom plate 1 through the reflection prism 4, and the reflected laser is emitted perpendicular to the bottom plate 1 through the collimator lens group 7. In this embodiment, the bottom plate 1 and the tube wall 2 constitute a tube shell, and the material of the tube shell can be metal or ceramic. The collimating lens group 7 may include a plurality of collimating lenses, and the collimating lenses are arranged in a one-to-one correspondence with the semiconductor lasers 3 , and are used to collimate the laser light emitted by each semiconductor laser 3 .

[0050] In some embodiments, the laser light source may be a side-emitting laser light source, which does not require a reflecting prism. Fig. 9As shown, the laser light source includes: a bottom plate 1, a tube wall 2, at least one semiconductor laser 3, a heat sink 5, a collimator lens group 7 and a sealing cover 8. The semiconductor laser 3 is welded on the heat sink 5, the tube wall 2 and the semiconductor laser 3 are both fixed on the bottom plate 1, and the tube wall 2 is a transparent material, the semiconductor laser 3 is surrounded by the tube wall 2, the sealing cover 8 is sealed on the tube wall 2, and the collimator lens group 7 is located on one side of the tube wall 2. The laser emitted by the semiconductor laser 3 directly passes through the tube wall 2 and then is emitted parallel to the bottom plate 1 through the collimator lens group 7.

[0051] The laser light source provided in this embodiment includes the semiconductor laser provided in the embodiment of the present application, and has corresponding functions and beneficial effects, which will not be described in detail here.

[0052] In addition, the embodiment of the present application also provides a laser projection device, Fig.10 FIG. 4 shows a block diagram of a laser projection device in some embodiments. Fig.10 As shown, the laser projection device includes: a display control component 10, a laser light source driving component 20, a laser light source 30, a light valve 40 and a lens 50; the display control component 10 is respectively connected to the laser light source driving component 20 and the light valve 40, and the laser light source driving component 20 is also connected to the laser light source 30.

[0053] The laser light source driving assembly 20 is one or more, and the laser light source 30 includes a semiconductor laser corresponding to the laser light source driving assembly 20, which may include a blue light semiconductor laser, a red light semiconductor laser, and a green light semiconductor laser. The display control assembly 10 may include a digital light processing chip (DLPC). For example, the digital light processing chip may be a DLPC 3437. The light valve 40 may be a digital micro-mirror device (DMD). The light valve 40 is used to modulate the laser light beam emitted from the laser light source 30 to generate an image beam, and to direct the image beam to the lens 50 so that the image beam is projected through the lens 50 to form an image.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0055] For the convenience of explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are to better explain the principles and practical applications, so that those skilled in the art can better use the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. A semiconductor laser, characterized in that: It includes an N-type substrate and an N-type confinement layer, an N-type waveguide layer, an N-side barrier layer, a quantum well layer, a P-side barrier layer, a P-type waveguide layer and a P-type confinement layer sequentially stacked on the N-type substrate; The N-type confinement layer and the P-type confinement layer form an asymmetric confinement layer structure, and the N-type waveguide layer and the P-type waveguide layer form an asymmetric waveguide layer structure; The N-side barrier layer and the P-side barrier layer have different thicknesses.

2. The semiconductor laser according to claim 1, characterized in that The thickness of the N-side barrier layer is greater than the thickness of the P-side barrier layer.

3. The semiconductor laser according to claim 2, characterized in that The thickness δn of the N-side barrier layer and the thickness δp of the P-side barrier layer satisfy the following relationship: α=δn / (δn+δp), wherein α is greater than 0.5 and less than 0.

8.

4. The semiconductor laser according to claim 1, characterized in that The thickness of the N-side barrier layer is smaller than the thickness of the P-side barrier layer.

5. The semiconductor laser according to claim 4, characterized in that The thickness δn of the N-side barrier layer and the thickness δp of the P-side barrier layer satisfy the following relationship: α=δn / (δn+δp), wherein α is greater than 0.3 and less than 0.

5.

6. The semiconductor laser according to any one of claims 2 to 5, characterized in that: The thickness of the P-side barrier layer is 10 nm to 100 nm.

7. The semiconductor laser according to claim 1, characterized in that The N-side barrier layer and the P-side barrier layer are compositionally graded barrier layers.

8. The semiconductor laser according to claim 1, characterized in that The thickness of the N-type confinement layer is greater than that of the P-type confinement layer, and the thickness of the N-type waveguide layer is greater than that of the P-type waveguide layer.

9. A laser light source, characterized in that: It comprises a bottom plate, a tube wall, at least one semiconductor laser as claimed in any one of claims 1 to 8, and a collimating lens group; The tube wall and the semiconductor laser are both located on the bottom plate, and the tube wall is arranged around the semiconductor laser. The collimating lens group is used for collimating the laser emitted by the semiconductor laser.

10. A laser projection device, characterized in that: include: A display control component, a laser light source driving component, a laser light source as claimed in claim 9, a light valve and a lens; The display control component is connected to the laser light source driving component and the light valve respectively, and the laser light source driving component is also connected to the laser light source.

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