CN213845835U

CN213845835U - Semiconductor laser with small volume and high power

Info

Publication number: CN213845835U
Application number: CN202023259144.9U
Authority: CN
Inventors: 周少丰; 黄良杰; 聂晓; 尹晓峰; 屈泽云
Original assignee: Shenzhen Xinghan Laser Technology Co Ltd
Current assignee: Shenzhen Xinghan Laser Technology Co Ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-07-30
Anticipated expiration: 2030-12-29

Abstract

The utility model provides a semiconductor laser of little volume high power, include: the device comprises a shell, a first light-emitting module, a second light-emitting module, a third light-emitting module, a fourth light-emitting module, a fifth reflector, a polarization beam combiner, a focusing lens and an output optical fiber, wherein the first light-emitting module, the second light-emitting module, the third light-emitting module, the fourth light-emitting module, the fifth reflector, the polarization beam combiner, the focusing lens and the output optical fiber are packaged in the shell; the first to fourth light emitting modules each include a plurality of light emitting cells; the first light-emitting module and the fourth light-emitting module are respectively positioned at two sides of the shell, and the second light-emitting module and the third light-emitting module are positioned in the middle of the shell; each light-emitting unit in the second light-emitting module and each light-emitting unit in the third light-emitting module are sequentially and alternately arranged in an alternating mode, so that the transverse size of the laser is shortened, the overall size of the laser is reduced under the condition that the output power of the laser is not changed, and the heat dissipation efficiency of the laser is improved.

Description

Semiconductor laser with small volume and high power

Technical Field

The utility model relates to a semiconductor laser technical field especially relates to a semiconductor laser of little volume high power.

Background

The semiconductor laser is a device capable of emitting laser, laser is generated by a laser chip arranged in the semiconductor laser, but the power of the laser emitted by a single laser chip is limited, and the generated laser power cannot meet the actual requirement, so that the laser emitted by a plurality of laser chips is required to be polarized and combined by a polarization beam combiner, and the power of the laser can be ensured; the higher the power, the more the number of laser chips, and the more laser chips need a large space to be arranged, which leads to an oversized laser without reasonable and skillful layout. Therefore, how to control the volume of the laser within a certain range and ensure the power output requirement of the laser is an important issue in the technical field of semiconductor lasers.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving the technical problem existing in the prior art, and providing a semiconductor laser with small volume and high power. The layout of four rows of chips is adopted, the total output power of the laser can be ensured, the two chips in the middle are arranged in an alternating mode, the space between the four rows of chips can be shortened, the overall size of the laser is reduced, and the heat dissipation efficiency is improved.

A small volume high power semiconductor laser comprising: the device comprises a shell, a first light-emitting module, a second light-emitting module, a third light-emitting module, a fourth light-emitting module, a fifth reflector, a polarization beam combiner, a focusing lens and an output optical fiber, wherein the first light-emitting module, the second light-emitting module, the third light-emitting module, the fourth light-emitting module, the fifth reflector, the polarization beam combiner, the focusing lens and the output optical fiber are packaged in the shell; the first to fourth light emitting modules each include a plurality of light emitting cells; the first light-emitting module and the fourth light-emitting module are respectively positioned at two sides of the shell, and the second light-emitting module and the third light-emitting module are positioned in the middle of the shell; each light-emitting unit in the second light-emitting module and each light-emitting unit in the third light-emitting module are sequentially and alternately arranged in an inserting manner;

the fifth reflector is arranged in the common light emitting direction of the third light emitting module and the fourth light emitting module, the polarization beam combiner is arranged in the common light emitting direction of the first light emitting module, the second light emitting module and the fifth reflector, the focusing lens is arranged in the light emitting direction of the polarization beam combiner, and the output optical fiber is arranged in the light emitting direction of the focusing lens.

Furthermore, the polarization beam combiner is formed by splicing and fixing two oppositely arranged triple prisms and comprises a first light incident surface, a second light incident surface, a beam combining surface, a light emergent surface and a half-wave plate; the first light incident surface and the light emergent surface are vertical to each other and are positioned on the same prism; the second light incident surface and the light emergent surface are parallel to each other, and the beam combining surface is positioned at the joint of the two triangular prisms; the half-wave plate is attached to the second light incident surface; the beam combining surface is plated with a film layer which transmits P polarized light and reflects S polarized light; the laser light emitted by the first light-emitting module to the fourth light-emitting module is S polarized light.

Further, the first light-emitting module comprises a plurality of first light-emitting units which are sequentially arranged in a line, the second light-emitting module comprises a plurality of second light-emitting units which are sequentially arranged in a line, the third light-emitting module comprises a plurality of third light-emitting units which are sequentially arranged in a line, and the fourth light-emitting module comprises a plurality of fourth light-emitting units which are sequentially arranged in a line; the plurality of first light-emitting units, the plurality of second light-emitting units, the plurality of third light-emitting units and the plurality of fourth light-emitting units are sequentially arranged in a step shape from high to low.

Further, the step height corresponding to each first light-emitting unit in the first light-emitting module is in direct proportion to the distance of the polarization beam combiner, that is, the step height where the first light-emitting unit closer to the polarization beam combiner is located is lower, and the step height where the first light-emitting unit farther from the polarization beam combiner is located is higher; the step height corresponding to each second light-emitting unit in the second light-emitting module is in direct proportion to the distance of the polarization beam combiner, that is, the step height of the second light-emitting unit closer to the polarization beam combiner is lower, and the step height of the second light-emitting unit farther from the polarization beam combiner is higher.

Further, the step height corresponding to each third light emitting unit in the third light emitting module is in direct proportion to the distance of the fifth reflector, that is, the step height of the third light emitting unit closer to the fifth reflector is lower, and the step height of the third light emitting unit farther from the fifth reflector is higher; the step height corresponding to each fourth light-emitting unit in the fourth light-emitting module is in direct proportion to the distance between the fifth reflector, that is, the step height of the fourth light-emitting unit closer to the fifth reflector is lower, and the step height of the fourth light-emitting unit farther from the fifth reflector is higher.

Further, the first light emitting unit comprises a first laser chip, a first fast axis collimating mirror, a first slow axis collimating mirror and a first reflector; the first fast axis collimating mirror is arranged in the light emergent direction of the first laser chip, the first slow axis collimating mirror is arranged in the light emergent direction of the first fast axis collimating mirror, and the first reflector is arranged in the light emergent direction of the first slow axis collimating mirror; the second light-emitting unit comprises a second laser chip, a second fast axis collimating mirror, a second slow axis collimating mirror and a second reflecting mirror, the second fast axis collimating mirror is arranged in the light-emitting direction of the second laser chip, the second slow axis collimating mirror is arranged in the light-emitting direction of the second fast axis collimating mirror, and the second reflecting mirror is arranged in the light-emitting direction of the second slow axis collimating mirror; the third light-emitting unit comprises a third laser chip, a third fast axis collimating mirror, a third slow axis collimating mirror and a third reflector, the third fast axis collimating mirror is arranged in the light-emitting direction of the third laser chip, the third slow axis collimating mirror is arranged in the light-emitting direction of the third fast axis collimating mirror, and the third reflector is arranged in the light-emitting direction of the third slow axis collimating mirror; the fourth luminescence unit comprises a fourth laser chip, a fourth fast axis collimating mirror, a fourth slow axis collimating mirror and a fourth reflector, the fourth fast axis collimating mirror is arranged in the light emitting direction of the fourth laser chip, the fourth slow axis collimating mirror is arranged in the light emitting direction of the fourth fast axis collimating mirror, and the fourth reflector is arranged in the light emitting direction of the fourth slow axis collimating mirror.

Furthermore, a first area, a second area, a third area, a fourth area, a fifth area and a sixth area are arranged in the shell side by side in sequence.

Furthermore, a plurality of first laser chips and a plurality of first fast axis collimating lenses corresponding to the plurality of first light emitting units are arranged in the first area and are arranged on a straight line; the second laser chips and the second fast axis collimating lenses corresponding to the second light emitting units are arranged in the fourth area and are arranged on a straight line; a plurality of first slow axis collimating mirrors and first reflecting mirrors corresponding to the plurality of first light emitting units are arranged in the second area; wherein a plurality of the first slow axis collimating mirrors are arranged in a straight line; a plurality of second slow-axis collimating mirrors and second reflecting mirrors corresponding to the plurality of fourth light-emitting units are arranged in the second area; wherein a plurality of the second slow axis collimating mirrors are arranged in a straight line; the first reflectors and the second reflectors are alternately arranged in sequence and are arranged on a straight line.

Furthermore, a plurality of third laser chips and a plurality of third fast axis collimating lenses corresponding to the plurality of third light emitting units are arranged in the third region and are arranged on a straight line; a plurality of fourth laser chips and a plurality of fourth fast axis collimating lenses corresponding to the plurality of fourth light emitting units are arranged in the sixth area and are arranged on a straight line; a plurality of third slow-axis collimating mirrors and third reflecting mirrors corresponding to the plurality of third light-emitting units are arranged in the fifth area; wherein a plurality of the third slow axis collimating mirrors are arranged in a straight line; a plurality of fourth slow-axis collimating mirrors and fourth reflecting mirrors corresponding to the plurality of fourth light-emitting units are arranged in the fifth area; wherein a plurality of the fourth slow axis collimating lenses are arranged in a straight line; the third reflectors and the fourth reflectors are alternately arranged in sequence and are arranged on a straight line.

Furthermore, each first light-emitting unit corresponds to each third light-emitting unit one by one, each second light-emitting unit corresponds to each fourth light-emitting unit one by one, and the third laser chip in the third light-emitting unit is located between the second laser chip in the second light-emitting unit and the second reflector.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 and fig. 2 are structural diagrams of a small-sized high-power semiconductor laser according to an embodiment of the present invention;

fig. 3a and fig. 3b are structural diagrams of the polarization beam combiner in the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

An embodiment of the utility model provides a semiconductor laser of little volume high power.

Referring to fig. 1 and fig. 2, fig. 1 and fig. 2 are structural diagrams of a small-sized high-power semiconductor laser according to an embodiment of the present invention, including: the light source comprises a shell 9, and a first light emitting module, a second light emitting module, a third light emitting module, a fourth light emitting module, a fifth reflector 5, a polarization beam combiner 6, a focusing lens 7 and an output optical fiber 8 which are packaged in the shell 9; wherein the first to fourth light emitting modules each include a plurality of light emitting cells; the first light-emitting module and the fourth light-emitting module are respectively positioned at two sides of a shell 9, and the second light-emitting module and the third light-emitting module are positioned in the middle of the shell 9; and each light-emitting unit in the second light-emitting module and each light-emitting unit in the third light-emitting module are alternately arranged in sequence.

The fifth reflector 5 is arranged in the common light emitting direction of the third light emitting module and the fourth light emitting module, the polarization beam combiner 6 is arranged in the common light emitting direction of the first light emitting module, the second light emitting module and the fifth reflector 5, the focusing lens 7 is arranged in the light emitting direction of the polarization beam combiner 6, and the output optical fiber 8 is arranged in the light emitting direction of the focusing lens 7. The laser emitted by the first light-emitting module and the laser emitted by the second light-emitting module directly enter the polarization beam combiner 6, and the laser emitted by the third light-emitting module and the laser emitted by the fourth light-emitting module enter the polarization beam combiner 6 after being reflected by the fifth reflector 5; the polarization beam combiner 6 outputs the received laser after polarization beam combination to the focusing lens 7, and the focusing lens 7 focuses the received laser in the fast and slow axis directions and then couples the focused laser to the output optical fiber 8 for output. Focusing lens 7 includes fast axle focusing lens 71 and slow axle focusing lens 72, fast axle focusing lens 71 sets up on the light-emitting direction of polarization beam combiner 6 for focus on laser in fast axle direction, slow axle focusing lens 72 sets up on fast axle focusing lens 71's the light-emitting direction, be used for focusing on laser in the slow axle direction.

Referring to fig. 3a, fig. 3a is a structural diagram of the polarization beam combiner 6 in the embodiment; the polarization beam combiner 6 is formed by splicing and fixing two oppositely arranged triangular prisms and comprises a first light incident surface 61, a second light incident surface 62, a beam combining surface 63, a light emitting surface 64 and a half-wave plate 65; the first light incident surface 61 and the light emergent surface 64 are perpendicular to each other and are located on the same prism; the second light incident surface 62 and the light emergent surface 64 are parallel to each other, and the beam combining surface 63 is located at the joint of the two triangular prisms; the half-wave plate 65 is attached to the second light incident surface 62; the beam combining surface 64 is plated with a film layer which transmits P polarized light and reflects S polarized light; the laser light emitted by the first light-emitting module to the fourth light-emitting module is S polarized light. The laser light emitted by the first light emitting module and the laser light emitted by the second light emitting module enter the beam combining surface 63 through the first light incident surface 61, and the S polarized light emitted by the third light emitting module and the S polarized light emitted by the fourth light emitting module are reflected to the polarization beam combiner 6 through the fifth reflecting mirror 5, converted into P polarized light through the half wave plate 65, and then enter the beam combining surface 63 through the second light incident surface 62; the beam combining surface 63 combines the received laser beams and outputs the combined laser beams through the light emitting surface 64.

Specifically, the first light-emitting module comprises a plurality of first light-emitting units 1 which are sequentially arranged in a line, the second light-emitting module comprises a plurality of second light-emitting units 2 which are sequentially arranged in a line, the third light-emitting module comprises a plurality of third light-emitting units 3 which are sequentially arranged in a line, and the fourth light-emitting module comprises a plurality of fourth light-emitting units 4 which are sequentially arranged in a line; the plurality of first light emitting units 1, the plurality of second light emitting units 2, the plurality of third light emitting units 3, and the plurality of fourth light emitting units 4 are sequentially arranged in a step shape from high to low.

The step height corresponding to each first light-emitting unit 1 in the first light-emitting module is proportional to the distance between the polarization beam combiner 6, that is, the lower the step height of the first light-emitting unit 1 closer to the polarization beam combiner 6 is, the higher the step height of the first light-emitting unit 1 farther from the polarization beam combiner 6 is, so that light spots output by the light path of each first light-emitting unit 1 cannot be superposed together and can enter the polarization beam combiner 6; the step height corresponding to each second light-emitting unit 2 in the second light-emitting module is proportional to the distance between the polarization beam combiner 6, that is, the lower the step height of the second light-emitting unit 2 closer to the polarization beam combiner 6 is, the higher the step height of the second light-emitting unit 2 farther from the polarization beam combiner 6 is, so that light spots output by the light path of each first light-emitting unit 1 cannot be superposed together and can enter the polarization beam combiner 6; in addition, the step difference between two adjacent first light-emitting units 1 is the same as the step difference between two adjacent second light-emitting units 2, and is a preset first height; and the step difference between the adjacent first light-emitting units 1 and second light-emitting units 2 is half of the first height, so that the light spots output by the light path where each first light-emitting unit 1 is located and the light spots output by the light path where each second light-emitting unit 2 is located are alternately arranged in the vertical direction, are not overlapped, and can enter the polarization beam combiner 6.

The step height corresponding to each third light-emitting unit 3 in the third light-emitting module is proportional to the distance between the fifth reflector 5, that is, the step height where the third light-emitting unit 3 closer to the fifth reflector 5 is located is lower, and the step height where the third light-emitting unit 3 farther from the fifth reflector 5 is located is higher, so that light spots output by the light path where each third light-emitting unit 3 is located can enter the fifth reflector 5 without being overlapped; the step height corresponding to each fourth light-emitting unit 4 in the fourth light-emitting module is proportional to the distance between the fifth reflector 5, that is, the lower the step height of the fourth light-emitting unit 4 closer to the fifth reflector 5 is, the higher the step height of the fourth light-emitting unit 4 farther from the fifth reflector 5 is, so that light spots output by the light path of each fourth light-emitting unit 4 can enter the fifth reflector 5 without being overlapped; in addition, the step difference between two adjacent third light-emitting units 3 is the same as the step difference between two adjacent fourth light-emitting units 4, and is a preset second height; and the step difference between the adjacent third light-emitting units 3 and fourth light-emitting units 4 is half of the second height, so that the light spots output by the light path of each third light-emitting unit 3 and the light spots output by the light path of each fourth light-emitting unit 4 are alternately arranged in the vertical direction, are not overlapped, and can enter the fifth reflector 5.

The first light-emitting unit 1 comprises a first laser chip 11, a first fast axis collimating mirror 12, a first slow axis collimating mirror 13 and a first reflector 14; the first fast axis collimator 12 is arranged in the light outgoing direction of the first laser chip 11, the first slow axis collimator 13 is arranged in the light outgoing direction of the first fast axis collimator 12, and the first reflector 14 is arranged in the light outgoing direction of the first slow axis collimator 13; the second light-emitting unit 2 includes a second laser chip 21, a second fast axis collimator 22, a second slow axis collimator 23, and a second reflector 24, the second fast axis collimator 22 is disposed in the light-emitting direction of the second laser chip 21, the second slow axis collimator 23 is disposed in the light-emitting direction of the second fast axis collimator 22, and the second reflector 24 is disposed in the light-emitting direction of the second slow axis collimator 23; the third light emitting unit 3 includes a third laser chip 31, a third fast axis collimator lens 32, a third slow axis collimator lens 33, and a third reflector 34, the third fast axis collimator lens 32 is disposed in the light emitting direction of the third laser chip 31, the third slow axis collimator lens 33 is disposed in the light emitting direction of the third fast axis collimator lens 32, and the third reflector 34 is disposed in the light emitting direction of the third slow axis collimator lens 33; fourth luminescence unit 4 includes fourth laser chip 41, fourth fast axis collimating mirror 42, fourth slow axis collimating mirror 43 and fourth speculum 44, fourth fast axis collimating mirror 42 sets up on the light-emitting direction of fourth laser chip 41, fourth slow axis collimating mirror 43 sets up on the light-emitting direction of fourth fast axis collimating mirror 42, fourth speculum 44 sets up on the light-emitting direction of fourth slow axis collimating mirror 43.

A first area 01, a second area 02, a third area 03, a fourth area 04, a fifth area 05 and a sixth area 06 are arranged in the shell 9 side by side in sequence; a plurality of first laser chips 11 and a plurality of first fast axis collimating mirrors 12 corresponding to the plurality of first light emitting units 1 are all arranged in the first area 01 and are arranged in a straight line; a plurality of second laser chips 21 and a plurality of second fast axis collimating lenses 22 corresponding to the plurality of second light emitting units 2 are all disposed in the fourth region 04 and are arranged in a straight line; a plurality of first slow axis collimating mirrors 13 and first reflecting mirrors 14 corresponding to the plurality of first light emitting units 1 are arranged in the second area 02; wherein a plurality of the first slow axis collimating mirrors 13 are arranged in a straight line; a plurality of second slow-axis collimating mirrors 23 and second reflecting mirrors 24 corresponding to a plurality of the fourth light-emitting units 2 are arranged in the second area 02; wherein a plurality of the second slow axis collimating mirrors 23 are arranged in a straight line; the first reflecting mirrors 14 and the second reflecting mirrors 24 are alternately arranged in sequence and are arranged in a straight line.

A plurality of third laser chips 31 and a plurality of third fast axis collimating mirrors 32 corresponding to the plurality of third light emitting units 3 are all disposed in the third region 03 and are arranged in a straight line; a plurality of fourth laser chips 41 and a plurality of fourth fast axis collimating mirrors 42 corresponding to the plurality of fourth light emitting units 4 are all disposed in the sixth area 06 and are arranged in a straight line; a plurality of third slow axis collimating mirrors 33 and third reflecting mirrors 34 corresponding to the plurality of third light emitting units 3 are all arranged in the fifth area 05; wherein a plurality of the third slow axis collimating mirrors 33 are arranged in a straight line; a plurality of fourth slow axis collimating mirrors 43 and fourth reflecting mirrors 44 corresponding to the plurality of fourth light emitting units 4 are all arranged in the fifth area 05; wherein a plurality of the fourth slow axis collimating mirrors 43 are arranged in a straight line; the third reflecting mirrors 34 and the fourth reflecting mirrors 44 are alternately arranged in sequence and are arranged on a straight line.

In a preferred embodiment, the number of the light emitting units in the first light emitting module, the second light emitting module, the third light emitting module and the fourth light emitting module is the same; each first light emitting unit 1 corresponds to each third light emitting unit 3 one to one, each second light emitting unit corresponds to each fourth light emitting unit 4 one to one, and the third laser chip 31 in the third light emitting unit 3 is located between the second laser chip 21 in the second light emitting unit 2 and the second reflector 24.

In the above embodiment, the distance of the middle two rows of light emitting units in the four rows of light emitting units of the laser is shortened by alternately inserting, that is, each second light emitting unit 2 and each third light emitting unit 3 are sequentially and alternately inserted to shorten the transverse size of the laser, so that the overall size of the laser is reduced and the heat dissipation efficiency of the laser is improved under the condition that the output power of the laser is not changed.

It should be noted that: in the practical use process, a person skilled in the art may also set the focusing lens 7 to be a single lens having both the fast axis focusing function and the slow axis focusing function according to the requirement. The position of the half-wave plate 65 and the polarization states of the laser beams emitted by the first to fourth light-emitting modules may also be changed according to actual requirements, for example: the half-wave plate 65 is attached to the first light incident surface 61, and as shown in fig. 3b, the laser beams emitted by the first to fourth light emitting modules are all P-polarized light.

In the present disclosure, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise direct contact between the first and second features through another feature not in direct contact. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the description in the above embodiments and the description is only preferred examples of the present invention, and is not intended to limit the present invention, and that the present invention can have various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications all fall into the scope of the claimed invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A small volume high power semiconductor laser comprising: the device comprises a shell, a first light-emitting module, a second light-emitting module, a third light-emitting module, a fourth light-emitting module, a fifth reflector, a polarization beam combiner, a focusing lens and an output optical fiber, wherein the first light-emitting module, the second light-emitting module, the third light-emitting module, the fourth light-emitting module, the fifth reflector, the polarization beam combiner, the focusing lens and the output optical fiber are packaged in the shell; the first to fourth light emitting modules each include a plurality of light emitting cells; the first light-emitting module and the fourth light-emitting module are respectively positioned at two sides of the shell, and the second light-emitting module and the third light-emitting module are positioned in the middle of the shell; the method is characterized in that: each light-emitting unit in the second light-emitting module and each light-emitting unit in the third light-emitting module are sequentially and alternately arranged in an inserting manner;

2. A small-volume high-power semiconductor laser as claimed in claim 1, wherein: the polarization beam combiner is formed by splicing and fixing two oppositely arranged triangular prisms and comprises a first light incident surface, a second light incident surface, a beam combining surface, a light emitting surface and a half-wave plate; the first light incident surface and the light emergent surface are vertical to each other and are positioned on the same prism; the second light incident surface and the light emergent surface are parallel to each other, and the beam combining surface is positioned at the joint of the two triangular prisms; the half-wave plate is attached to the second light incident surface; the beam combining surface is plated with a film layer which transmits P polarized light and reflects S polarized light; the laser light emitted by the first light-emitting module to the fourth light-emitting module is S polarized light.

3. A small-volume high-power semiconductor laser as claimed in claim 1, wherein: the first light-emitting module comprises a plurality of first light-emitting units which are sequentially arranged in a line, the second light-emitting module comprises a plurality of second light-emitting units which are sequentially arranged in a line, the third light-emitting module comprises a plurality of third light-emitting units which are sequentially arranged in a line, and the fourth light-emitting module comprises a plurality of fourth light-emitting units which are sequentially arranged in a line; the plurality of first light-emitting units, the plurality of second light-emitting units, the plurality of third light-emitting units and the plurality of fourth light-emitting units are sequentially arranged in a step shape from high to low.

4. A small-volume high-power semiconductor laser as claimed in claim 3, wherein: the step height corresponding to each first light-emitting unit in the first light-emitting module is in direct proportion to the distance of the polarization beam combiner, namely, the step height of the first light-emitting unit which is closer to the polarization beam combiner is lower, and the step height of the first light-emitting unit which is farther from the polarization beam combiner is higher; the step height corresponding to each second light-emitting unit in the second light-emitting module is in direct proportion to the distance of the polarization beam combiner, that is, the step height of the second light-emitting unit closer to the polarization beam combiner is lower, and the step height of the second light-emitting unit farther from the polarization beam combiner is higher.

5. A small-volume high-power semiconductor laser as claimed in claim 3, wherein: the step height corresponding to each third light-emitting unit in the third light-emitting module is in direct proportion to the distance of the fifth reflector, namely, the step height of the third light-emitting unit which is closer to the fifth reflector is lower, and the step height of the third light-emitting unit which is farther from the fifth reflector is higher; the step height corresponding to each fourth light-emitting unit in the fourth light-emitting module is in direct proportion to the distance between the fifth reflector, that is, the step height of the fourth light-emitting unit closer to the fifth reflector is lower, and the step height of the fourth light-emitting unit farther from the fifth reflector is higher.

6. A small-volume high-power semiconductor laser as claimed in claim 3, wherein: the first light-emitting unit comprises a first laser chip, a first fast axis collimating mirror, a first slow axis collimating mirror and a first reflector; the first fast axis collimating mirror is arranged in the light emergent direction of the first laser chip, the first slow axis collimating mirror is arranged in the light emergent direction of the first fast axis collimating mirror, and the first reflector is arranged in the light emergent direction of the first slow axis collimating mirror; the second light-emitting unit comprises a second laser chip, a second fast axis collimating mirror, a second slow axis collimating mirror and a second reflecting mirror, the second fast axis collimating mirror is arranged in the light-emitting direction of the second laser chip, the second slow axis collimating mirror is arranged in the light-emitting direction of the second fast axis collimating mirror, and the second reflecting mirror is arranged in the light-emitting direction of the second slow axis collimating mirror; the third light-emitting unit comprises a third laser chip, a third fast axis collimating mirror, a third slow axis collimating mirror and a third reflector, the third fast axis collimating mirror is arranged in the light-emitting direction of the third laser chip, the third slow axis collimating mirror is arranged in the light-emitting direction of the third fast axis collimating mirror, and the third reflector is arranged in the light-emitting direction of the third slow axis collimating mirror; the fourth luminescence unit comprises a fourth laser chip, a fourth fast axis collimating mirror, a fourth slow axis collimating mirror and a fourth reflector, the fourth fast axis collimating mirror is arranged in the light emitting direction of the fourth laser chip, the fourth slow axis collimating mirror is arranged in the light emitting direction of the fourth fast axis collimating mirror, and the fourth reflector is arranged in the light emitting direction of the fourth slow axis collimating mirror.

7. A small-volume high-power semiconductor laser as claimed in claim 6, wherein: a first area, a second area, a third area, a fourth area, a fifth area and a sixth area are sequentially arranged in the shell side by side.

8. A small-volume high-power semiconductor laser as claimed in claim 7, wherein: the first laser chips and the first fast axis collimating lenses corresponding to the first light emitting units are arranged in the first area and are arranged on a straight line; the second laser chips and the second fast axis collimating lenses corresponding to the second light emitting units are arranged in the fourth area and are arranged on a straight line; a plurality of first slow axis collimating mirrors and first reflecting mirrors corresponding to the plurality of first light emitting units are arranged in the second area; wherein a plurality of the first slow axis collimating mirrors are arranged in a straight line; a plurality of second slow-axis collimating mirrors and second reflecting mirrors corresponding to the plurality of fourth light-emitting units are arranged in the second area; wherein a plurality of the second slow axis collimating mirrors are arranged in a straight line; the first reflectors and the second reflectors are alternately arranged in sequence and are arranged on a straight line.

9. A small-volume high-power semiconductor laser as claimed in claim 8, wherein: a plurality of third laser chips and a plurality of third fast axis collimating lenses corresponding to the plurality of third light emitting units are arranged in the third area and are arranged on a straight line; a plurality of fourth laser chips and a plurality of fourth fast axis collimating lenses corresponding to the plurality of fourth light emitting units are arranged in the sixth area and are arranged on a straight line; a plurality of third slow-axis collimating mirrors and third reflecting mirrors corresponding to the plurality of third light-emitting units are arranged in the fifth area; wherein a plurality of the third slow axis collimating mirrors are arranged in a straight line; a plurality of fourth slow-axis collimating mirrors and fourth reflecting mirrors corresponding to the plurality of fourth light-emitting units are arranged in the fifth area; wherein a plurality of the fourth slow axis collimating lenses are arranged in a straight line; the third reflectors and the fourth reflectors are alternately arranged in sequence and are arranged on a straight line.

10. A small-volume high-power semiconductor laser as claimed in claim 9, wherein: each first light-emitting unit corresponds to each third light-emitting unit one by one, each second light-emitting unit corresponds to each fourth light-emitting unit one by one, and a third laser chip in each third light-emitting unit is positioned between a second laser chip in each second light-emitting unit and the second reflector.