Semiconductor laser
By plating a high-transparency high-reverse film on the body Bragg grating and setting it inclinedly, the problem of insufficient anti-reverse ability of semiconductor lasers is solved, and a smaller size and lower cost design is achieved, while ensuring the stability and temperature of the laser wavelength stability.
Patent Information
- Application Number
- CN202411370881.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-01-07
AI Technical Summary
In the pursuit of smaller size, lower weight and higher reliability, existing semiconductor lasers have insufficient anti-high-reflection capabilities, resulting in reduced performance, and increasing anti-high-reflection to improve stability will increase cost and volume.
The high-transmissive high-reflection film is coated outside the body Bragg grating and set inclined to allow the light reflected by the high-transmissive high-reflection film to emit light outside the semiconductor laser chip, improving the resistance to high-reflection capability, avoiding additional high-reflection mirrors, reducing costs and size.
It improves the high-reverse resistance resistance of semiconductor lasers, reduces size and cost, and ensures the stability of laser wavelength and temperature stability, and improves overall performance.
Smart Images
Figure CN119275713A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor lasers, and in particular to a semiconductor laser. Background Art
[0002] Semiconductor lasers have the advantages of small size, high efficiency, long life, and strong stability. With the widespread application of lasers in industrial processing, military, medical, laser radar and other fields, semiconductor lasers are increasingly used as pump sources and seed sources for fiber lasers and solid-state lasers. In particular, wavelength-locked semiconductor lasers are widely used in the fields of fiber lasers and solid-state lasers due to their excellent wavelength stability and narrow linewidth.
[0003] With the rapid development of the laser field, the market has higher requirements for power, brightness and other indicators, as well as the size and reliability of semiconductor laser pump sources. Especially in the field of military equipment, there are extremely high requirements for the size, weight and reliability of lasers, and semiconductor laser pump sources or seed sources, which are the source of laser power, also pursue smaller size, lower weight, higher reliability and cost. Summary of the invention
[0004] The main purpose of the present invention is to provide a semiconductor laser, aiming to solve the problem of how to reduce the size of the semiconductor laser.
[0005] To achieve the above object, the semiconductor laser proposed in the present invention comprises:
[0006] Semiconductor laser chips;
[0007] A fast axis collimator, which is arranged on the light-emitting side of the semiconductor laser chip;
[0008] A slow axis collimator, which is arranged on the light-emitting side of the fast axis collimator;
[0009] A volume Bragg grating, wherein the surface of the volume Bragg grating is coated with a high-transmittance and high-reflection film, the wavelength band of the transmitted light of the high-transmittance and high-reflection film is adapted to the wavelength band of the light emitted by the semiconductor laser chip, the high-transmittance and high-reflection film can reflect light of a preset wavelength band, the preset wavelength band is different from the wavelength band of the light emitted by the semiconductor laser chip, and the volume Bragg grating is tilted so that the light reflected by the high-transmittance and high-reflection film is emitted to an area outside the semiconductor laser chip;
[0010] The outgoing light of the slow axis collimator can pass through the volume Bragg grating, or the volume Bragg grating is arranged between the fast axis collimator and the slow axis collimator.
[0011] In one embodiment, a plurality of grating structures are evenly arranged inside the volume Bragg grating, and an angle between each of the grating structures and an extension direction of the volume Bragg grating is 4.84° to 5.84°.
[0012] In one embodiment, the incident angle of the volume Bragg grating is 5° to 11°.
[0013] In one implementation, the preset wavelength band is 1020 nm to 1200 nm.
[0014] In one embodiment, the semiconductor laser further comprises a reflecting mirror and a focusing mirror, wherein the reflecting mirror is arranged on the light-emitting side of the slow-axis collimating mirror, and the focusing mirror is arranged on the light-emitting side of the reflecting mirror;
[0015] The volume Bragg grating is arranged between the slow axis collimator and the reflector, or the volume Bragg grating is arranged between the fast axis collimator and the slow axis collimator.
[0016] In one embodiment, the number of the semiconductor laser chips is multiple, and the multiple semiconductor laser chips are arranged in sequence along a first direction, the fast-axis collimator is consistent with the number of the semiconductor laser chips and is arranged one-to-one, the slow-axis collimator is consistent with the number of the semiconductor laser chips and is arranged one-to-one, the volume Bragg grating is consistent with the number of the semiconductor laser chips and is arranged one-to-one, and the reflector is consistent with the number of the semiconductor laser chips and is arranged one-to-one.
[0017] In one embodiment, the semiconductor laser further comprises a reflecting mirror and a focusing mirror, wherein the reflecting mirror is arranged on the light emitting side of the slow axis collimating mirror, the focusing mirror is arranged on the light emitting side of the reflecting mirror, and the volume Bragg grating is arranged between the reflecting mirror and the focusing mirror.
[0018] In one embodiment, the number of the semiconductor laser chips is multiple, and the multiple semiconductor laser chips are arranged in sequence along a first direction. The fast-axis collimator is consistent with the number of the semiconductor laser chips and is arranged one-to-one. The slow-axis collimator is consistent with the number of the semiconductor laser chips and is arranged one-to-one. The reflector is consistent with the number of the semiconductor laser chips and is arranged one-to-one. The multiple reflectors form a reflector group, and the volume Bragg grating is located between the reflector group and the focusing mirror.
[0019] In one embodiment, the semiconductor laser further comprises a focusing mirror, wherein the focusing mirror is arranged on the light-emitting side of the slow-axis collimating mirror, and the volume Bragg grating is arranged between the slow-axis collimating mirror and the focusing mirror.
[0020] In one embodiment, the semiconductor laser further comprises a focusing mirror, wherein the focusing mirror is arranged on the light-emitting side of the slow-axis collimating mirror, and the volume Bragg grating is arranged between the slow-axis collimating mirror and the fast-axis collimating mirror.
[0021] The technical solution of the present invention is to coat a high-transmittance and high-reflection film on the outside of the volume Bragg grating, and the volume Bragg grating is tilted so that the light reflected by the high-transmittance and high-reflection film is basically not reflected to the semiconductor laser chip, thereby improving the anti-high-reflection ability of the semiconductor laser. Therefore, there is no need to add an additional anti-high-reflection mirror, which not only reduces the cost but also reduces the size of the semiconductor laser. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.
[0023] Figure 1 A schematic structural diagram of an embodiment of a semiconductor laser provided by the present invention having multiple semiconductor laser chips;
[0024] Figure 2 A schematic structural diagram of another embodiment of a semiconductor laser device provided by the present invention having multiple semiconductor laser chips;
[0025] Figure 3 A schematic structural diagram of another embodiment of a semiconductor laser provided by the present invention having multiple semiconductor laser chips;
[0026] Figure 4 A schematic structural diagram of an embodiment of a semiconductor laser device provided by the present invention having a single semiconductor laser chip;
[0027] Figure 5 A schematic structural diagram of another embodiment of a semiconductor laser device provided by the present invention having a single semiconductor laser chip;
[0028] Figure 6 A schematic structural diagram of another embodiment of a semiconductor laser device provided by the present invention having a single semiconductor laser chip;
[0029] Figure 7 A schematic structural diagram of an embodiment of a volume Bragg grating provided by the present invention;
[0030] Figure 8 A schematic structural diagram of another viewing angle of an embodiment of a volume Bragg grating provided by the present invention;
[0031] Fig. 9 A schematic structural diagram of another viewing angle of an embodiment of a volume Bragg grating provided by the present invention.
[0032] Description of Figure Numbers:
[0033] 100. Semiconductor laser; 1. Semiconductor laser chip; 2. Fast axis collimator; 3. Slow axis collimator; 4. Volume Bragg grating; 41. Grating structure; 5. Reflector; 6. Focusing mirror; 7. Optical fiber.
[0034] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0036] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.
[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0038] Semiconductor lasers have the advantages of small size, high efficiency, long life, and strong stability. With the widespread application of lasers in industrial processing, military, medical, laser radar and other fields, semiconductor lasers are increasingly used as pump sources and seed sources for fiber lasers and solid-state lasers. In particular, wavelength-locked semiconductor lasers are widely used in the fields of fiber lasers and solid-state lasers due to their excellent wavelength stability and narrow linewidth.
[0039] With the rapid development of the laser field, the market has higher requirements for power, brightness and other indicators, as well as the size and reliability of semiconductor laser pump sources. Especially in the field of military equipment, there are extremely high requirements for the size, weight and reliability of lasers, and semiconductor laser pump sources or seed sources, which are the source of laser power, also pursue smaller size, lower weight, higher reliability and cost.
[0040] The inventors have found that a major indicator that determines the reliability of a semiconductor laser pump source or seed source is its ability to resist high reflection. Because whether it is a fiber laser or a solid-state laser, its performance indicators decline, and most of the chips in the semiconductor lasers fail. Therefore, the anti-high reflection ability of the semiconductor laser module is an important indicator that affects the performance of the entire fiber laser or solid-state laser. The current means of improving the anti-high reflection ability of semiconductor lasers is usually to add an anti-high reflection lens in the optical path to prevent the external light used for gain from interfering with the semiconductor chip, thereby improving the anti-high reflection ability of the semiconductor chip. Although the addition of the anti-high reflection lens improves the stability of the semiconductor laser, it also restricts the semiconductor laser from pursuing smaller size and lower quality.
[0041] In view of this, the present invention proposes a semiconductor laser, aiming to solve the problem of how to reduce the size of the semiconductor laser.
[0042] See also Figure 1 and Figure 3 In one embodiment of the present invention, the semiconductor laser 100 includes a semiconductor laser chip 1, a fast axis collimator 2, a slow axis collimator 3 and a volume Bragg grating 4, wherein the fast axis collimator 2 is arranged on the light-emitting side of the semiconductor laser chip 1; the slow axis collimator 3 is arranged on the light-emitting side of the fast axis collimator 2; the surface of the volume Bragg grating 4 is coated with a high-transmittance and high-reflection film, the wavelength band of the transmitted light of the high-transmittance and high-reflection film is adapted to the wavelength band of the emitted light of the semiconductor laser chip 1, the high-transmittance and high-reflection film can reflect the light of a preset wavelength band, the preset wavelength band is different from the wavelength band of the emitted light of the semiconductor laser chip 1, and the volume Bragg grating 4 is tilted so that the light reflected by the high-transmittance and high-reflection film is emitted to an area outside the semiconductor laser chip 1; the emitted light of the slow axis collimator 3 can pass through the volume Bragg grating 4, or the volume Bragg grating 4 is arranged between the fast axis collimator 2 and the slow axis collimator 3.
[0043] The technical solution of the present invention is to coat the volume Bragg grating 4 with a high-transmittance and high-reflection film, and the volume Bragg grating 4 is tilted, so that the high-transmittance and high-reflection film can reflect the light of the preset band to the area outside the semiconductor chip, thereby reducing or avoiding the phenomenon that this part of the light is directly directed to the semiconductor chip and causes the semiconductor chip to fail. Since the reflected light is basically not reflected to the semiconductor laser chip 1, the anti-high-reflection ability of the semiconductor laser 100 is improved, so there is no need to add an additional anti-high-reflection mirror, which not only reduces the cost but also reduces the size of the semiconductor laser 100. It should be noted that the light emitted from the fast axis collimator 2 passes through the high-transmittance and high-reflection film and is emitted to the volume Bragg grating 4. Since the high-transmittance and high-reflection film can increase the transmittance of the light in the same wavelength band emitted by the semiconductor laser chip 1, the interface loss of the light in this wavelength band is effectively reduced; wherein the volume Bragg grating 4 can reflect all or part of the laser of a specific wavelength in the laser emitted by the semiconductor laser chip 1 back to the semiconductor laser chip 1, and transmit lasers of other wavelengths, or transmit part of the laser of a specific wavelength, or transmit lasers of other wavelengths and part of the laser of a specific wavelength; this feedback light mechanism can lock the laser wavelength, so that the emission wavelength of the semiconductor laser chip 1 is single and stable, and since the output wavelength of the semiconductor laser chip 1 is determined by the volume Bragg grating 4, and the reflected light wave of the volume Bragg grating 4 changes with temperature much less than the laser medium itself, the semiconductor laser 100 output coupled by the volume Bragg grating 4 has the advantages of small output line width and high temperature stability. It should also be noted that the volume Bragg grating 4 can be tilted in the XOY plane, such as Figure 4 As shown, it can also be tilted relative to the Z axis, such as Figure 6 shown.
[0044] See also Figures 7 to 9 In one embodiment, a plurality of grating structures 41 are uniformly arranged inside the volume Bragg grating 4, and the angle between each grating structure 41 and the extension direction of the volume Bragg grating 4 is 4.84° to 5.84°. By setting the grating structure 41 inside the volume Bragg grating 4 to have an angle between 4.84° and 5.84° with respect to the extension direction of the volume Bragg grating 4, it is ensured that all or part of the light reflected by the volume Bragg grating 4 can be directed to the semiconductor chip. Fig. 9 β in .
[0045] In one embodiment, the incident angle of the volume Bragg grating 4 is 5° to 11°. Controlling the incident angle of the volume Bragg grating 4 within the range of 5° to 11° can make the high-transmittance and high-reflection film have a better anti-high-reflection effect. The included angle between the grating structure and the extension direction of the volume Bragg grating 4 is 4.84° to 5.84°, which can not only ensure that the light reflected by the volume Bragg grating 4 can be fully or partially directed to the semiconductor laser chip 1, reducing the mirror reflection signal of the volume Bragg grating 4 back to the laser chip, but also effectively avoid or reduce the external gain light from being directed to the semiconductor laser chip 1, which not only ensures the stability of the emission wavelength of the semiconductor laser chip 1, but also improves the anti-high-reflection ability of the semiconductor laser chip 1. Generally, the incident angle of the volume Bragg grating 4 is 8°. Among them, the incident angle of the volume Bragg grating 4 is Fig. 9 α shown.
[0046] In one embodiment, the preset wavelength is 1020nm to 1200nm. The preset wavelength is set to 1020nm to 1200nm. The light in this wavelength will have a greater impact on the semiconductor laser chip 1. Therefore, this part of the light is reflected to the area outside the semiconductor laser chip 1, thereby improving the anti-high reflection capability of the wavelength-locked semiconductor laser 100.
[0047] See also Figure 1 In one embodiment, the semiconductor laser 100 further includes a reflector 5 and a focusing mirror 6. The reflector 5 is arranged on the light-emitting side of the slow-axis collimator 3, and the focusing mirror 6 is arranged on the light-emitting side of the reflector 5; the volume Bragg grating 4 is arranged between the slow-axis collimator 3 and the reflector 5. Among them, the fast-axis collimator 2 is used to collimate the laser spot emitted from the semiconductor laser chip 1 on the fast axis before emitting it, and this part of light is then collimated by the slow-axis collimator 3 and then emitted to the volume Bragg grating 4, and the volume Bragg grating 4 is used to lock the laser light emitted from the slow-axis collimator 3 and / or filter it before emitting it to the reflector 5, and then reflected by the reflector 5 to the focusing mirror 6, and then focused by the focusing mirror 6 and emitted to the optical fiber 7.
[0048] See also Figure 3 In one embodiment, the semiconductor laser 100 further includes a reflector 5 and a focusing mirror 6. The reflector 5 is arranged on the light-emitting side of the slow-axis collimator 3, and the focusing mirror 6 is arranged on the light-emitting side of the reflector 5; the volume Bragg grating 4 is arranged between the fast-axis collimator 2 and the slow-axis collimator 3. The fast-axis collimator 2 is used to collimate the laser spot emitted from the semiconductor laser chip 1 and then emit it, and the volume Bragg grating 4 is used to lock and / or filter the laser emitted from the fast-axis collimator 2 and then emit it to the slow-axis collimator 3. The light is then collimated by the slow-axis collimator 3 and then emitted to the reflector 5, and then reflected by the reflector 5 to the focusing mirror 6, and then focused by the focusing mirror 6 and emitted to the optical fiber 7.
[0049] See also Figure 1and Figure 3 In one embodiment, there are multiple semiconductor laser chips 1, which are arranged in sequence along a first direction. The number of fast-axis collimators 2 is consistent with that of semiconductor laser chips 1 and they are arranged one-to-one. The number of slow-axis collimators 3 is consistent with that of semiconductor laser chips 1 and they are arranged one-to-one. The number of volume Bragg gratings 4 is consistent with that of semiconductor laser chips 1 and they are arranged one-to-one. The number of reflectors 5 is consistent with that of semiconductor laser chips 1 and they are arranged one-to-one. By arranging multiple semiconductor laser chips 1 to form a semiconductor laser array, the power and efficiency of the semiconductor laser 100 can be effectively improved. It should be noted that the first direction is Figure 1 Left and right directions shown.
[0050] See also Figure 2 In one embodiment, the semiconductor laser 100 further includes a reflector 5 and a focusing mirror 6. The reflector 5 is arranged on the light-emitting side of the slow-axis collimator 3, the focusing mirror 6 is arranged on the light-emitting side of the reflector 5, and the volume Bragg grating 4 is arranged between the reflector 5 and the focusing mirror 6. The fast-axis collimator 2 is used to perform fast-axis collimation on the laser spot emitted from the semiconductor laser chip 1 and then emit it to the slow-axis collimator 3. The light is collimated by the slow-axis collimator 3 and then emitted to the reflector 5. After being reflected by the reflector 5, the light is emitted to the volume Bragg grating 4. The volume Bragg grating 4 is used to perform wave locking and / or filtering on the laser reflected from the reflector 5 and then emit it to the focusing mirror 6. Then, the focusing mirror 6 focuses the laser light and then emits it to the optical fiber 7.
[0051] In one embodiment, there are multiple semiconductor laser chips 1, which are arranged in sequence along the first direction, the number of fast-axis collimators 2 is the same as that of semiconductor laser chips 1 and they are arranged one-to-one, the number of slow-axis collimators 3 is the same as that of semiconductor laser chips 1 and they are arranged one-to-one, the number of reflectors 5 is the same as that of semiconductor laser chips 1 and they are arranged one-to-one, the multiple reflectors 5 form a reflector group 5, and the volume Bragg grating 4 is located between the reflector group 5 and the focusing mirror 6. Compared with each semiconductor chip being provided with a corresponding volume Bragg grating 4, multiple semiconductor laser chips 1 share one volume Bragg grating 4, which has lower cost and more compact structure.
[0052] See also Figure 5 and Figure 6In one embodiment, the semiconductor laser 100 further includes a focusing lens 6, which is disposed on the light-emitting side of the slow-axis collimating lens 3, and a volume Bragg grating 4 is disposed between the slow-axis collimating lens 3 and the focusing lens 6. The fast-axis collimating lens 2 is used to perform fast-axis collimation on the laser spot emitted from the semiconductor laser chip 1 and then emit it to the slow-axis collimating lens 3, and the light is collimated by the slow-axis collimating lens 3 and then emitted to the volume Bragg grating 4, and the volume Bragg grating 4 is used to perform wave locking and / or filtering on the laser emitted from the slow-axis collimating lens 3 and then emit it to the focusing lens 6, and then the focusing lens 6 focuses and then emits it to the optical fiber 7.
[0053] See also Figure 4 In one embodiment, the semiconductor laser 100 further includes a focusing lens 6, which is disposed on the light-emitting side of the slow-axis collimating lens 3, and a volume Bragg grating 4 is disposed between the slow-axis collimating lens 3 and the fast-axis collimating lens 2. The fast-axis collimating lens 2 is used to collimate the laser spot emitted from the semiconductor laser chip 1 and then emit it, and the volume Bragg grating 4 is used to lock and / or filter the laser emitted from the fast-axis collimating lens 2 and then emit it to the slow-axis collimating lens 3, and the light is then collimated by the slow-axis collimating lens 3 and then emitted to the focusing lens 6, and then focused by the focusing lens 6 and emitted to the optical fiber 7.
[0054] The above are only exemplary embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.
Claims
1. A semiconductor laser, characterized in that: include: Semiconductor laser chips; A fast axis collimator, which is arranged on the light-emitting side of the semiconductor laser chip; A slow axis collimator, which is arranged on the light-emitting side of the fast axis collimator; A volume Bragg grating, wherein the surface of the volume Bragg grating is coated with a high-transmittance and high-reflection film, the wavelength band of the transmitted light of the high-transmittance and high-reflection film is adapted to the wavelength band of the light emitted by the semiconductor laser chip, the high-transmittance and high-reflection film can reflect light of a preset wavelength band, the preset wavelength band is different from the wavelength band of the light emitted by the semiconductor laser chip, and the volume Bragg grating is tilted so that the light reflected by the high-transmittance and high-reflection film is emitted to an area outside the semiconductor laser chip; The outgoing light of the slow axis collimator can pass through the volume Bragg grating, or the volume Bragg grating is arranged between the fast axis collimator and the slow axis collimator.
2. The semiconductor laser according to claim 1, characterized in that A plurality of grating structures are evenly arranged inside the volume Bragg grating, and an included angle between each of the grating structures and an extension direction of the volume Bragg grating is 4.84° to 5.84°.
3. The semiconductor laser according to claim 2, characterized in that The incident angle of the volume Bragg grating is 5° to 11°.
4. The semiconductor laser according to claim 1, characterized in that The preset wavelength band is 1020nm to 1200nm.
5. The semiconductor laser according to any one of claims 1 to 4, characterized in that The semiconductor laser further comprises a reflecting mirror and a focusing mirror, wherein the reflecting mirror is arranged on the light-emitting side of the slow-axis collimating mirror, and the focusing mirror is arranged on the light-emitting side of the reflecting mirror; The volume Bragg grating is arranged between the slow axis collimator and the reflector, or the volume Bragg grating is arranged between the fast axis collimator and the slow axis collimator.
6. The semiconductor laser according to claim 5, characterized in that There are multiple semiconductor laser chips, which are arranged in sequence along a first direction. The fast-axis collimator mirrors are consistent in number with the semiconductor laser chips and are arranged in one-to-one correspondence. The slow-axis collimator mirrors are consistent in number with the semiconductor laser chips and are arranged in one-to-one correspondence. The volume Bragg gratings are consistent in number with the semiconductor laser chips and are arranged in one-to-one correspondence. The reflector is consistent in number with the semiconductor laser chips and is arranged in one-to-one correspondence.
7. The semiconductor laser according to any one of claims 1 to 4, characterized in that The semiconductor laser also includes a reflecting mirror and a focusing mirror. The reflecting mirror is arranged on the light-emitting side of the slow-axis collimating mirror, the focusing mirror is arranged on the light-emitting side of the reflecting mirror, and the volume Bragg grating is arranged between the reflecting mirror and the focusing mirror.
8. The semiconductor laser according to claim 7, characterized in that There are multiple semiconductor laser chips, which are arranged in sequence along a first direction. The fast-axis collimator mirrors are consistent in number with the semiconductor laser chips and are arranged in one-to-one correspondence. The slow-axis collimator mirrors are consistent in number with the semiconductor laser chips and are arranged in one-to-one correspondence. The reflectors are consistent in number with the semiconductor laser chips and are arranged in one-to-one correspondence. The multiple reflectors form a reflector group, and the volume Bragg grating is located between the reflector group and the focusing mirror.
9. The semiconductor laser according to any one of claims 1 to 4, characterized in that The semiconductor laser further comprises a focusing mirror, which is arranged on the light-emitting side of the slow-axis collimating mirror, and the volume Bragg grating is arranged between the slow-axis collimating mirror and the focusing mirror.
10. The semiconductor laser according to any one of claims 1 to 4, characterized in that The semiconductor laser further comprises a focusing mirror, which is arranged on the light-emitting side of the slow-axis collimating mirror, and the volume Bragg grating is arranged between the slow-axis collimating mirror and the fast-axis collimating mirror.