A semiconductor laser step structure heat sink

Abstract

The invention provides a semiconductor laser step structure heat sink, comprising: a step heat sink; the step heat sink is provided with a plurality of step planes, and the height difference between each adjacent step plane increases from the middle to both sides; the step plane at the middle position on the step heat sink is in a parallel plane structure with the bottom surface; the laser chip outputs laser light through a fast axis collimator and a slow axis collimator to achieve spot shaping, and finally the light spot is rearranged through a reflector; the invention effectively avoids the reflector from blocking the reflected light beam on the high-order plane by controlling the height difference of the step plane, thereby improving the transmission efficiency of the light beam; the angle control of the step surface rearranges the light spots of multiple laser beams, thereby improving the laser power density in the center area of ​​the light spot, reducing the spherical aberration of the focusing lens, and effectively improving the coupling efficiency of multi-chip laser focusing.

Description

Technical Field

[0001] The present application belongs to the field of laser technology, and specifically, relates to semiconductor laser packaging technology. Background Art

[0002] Semiconductor lasers have the advantages of small size, light weight, long life, and wide wavelength coverage. However, due to the limitation of chip size, the output laser spot has a large divergence. The semiconductor laser pigtail output technology effectively improves its output spot characteristics, making semiconductor lasers widely used in military, medical, communication and other fields.

[0003] With the improvement of process technology, the output power of a single laser chip has achieved 20W output, but its power level still cannot meet the needs of industrial applications. In order to achieve high-power semiconductor laser output, two process methods are often used: one is to use a laser chip with a bar structure for beam shaping and rearrangement coupling. Its output power often reaches the KW power level, but its laser energy and power density are low; the other method is to spatially shape the light output by multiple laser chips and couple it into the optical fiber for transmission. This method arranges the spatial positions of multiple laser chips to achieve close arrangement of the output laser beams in front of the focusing lens, reduce the size of the light spot and achieve high-efficiency coupling. The use of multiple laser chip beam combining has currently achieved a 300W laser power output. Each laser chip often uses a stepped heat sink structure as a welding heat sink to achieve a stepped spatial arrangement of the laser chip, and a reflector is set at each step to achieve beam deflection of each laser chip. If the height difference of the step heat sink is set too large, the final rearranged light spot shape will be too large, and the aberration introduced in the lens focusing process will also be large; if the height difference is set too small, the reflector will intercept the high-order laser beam, resulting in a part of the laser being unable to be coupled to the optical fiber through the focusing lens. Both situations will directly reduce the laser coupling efficiency. Summary of the invention

[0004] In view of the above problems, the technical problem to be solved by the present application is to provide a new type of stepped structure heat sink.

[0005] The technical solution adopted by the present application to solve the above technical problems is: a semiconductor laser step structure heat sink, comprising: a step heat sink; a plurality of steps are arranged on the step heat sink; laser chips are respectively welded on the steps to achieve spatial distribution of the laser chips in the vertical direction; the laser chip outputs laser light through a fast axis collimator and a slow axis collimator to achieve spot shaping, and finally the light spot is rearranged through a reflector.

[0006] According to an embodiment of the present invention, the chip welding end on each step surface of the step structure heat sink is slightly higher than the other end, which is convenient for fixing the lens.

[0007] According to one embodiment of the present invention, the height difference of each step surface of the step structure heat sink increases from the middle to both sides. The middle position is defined as follows: when the number of steps is an odd number, the middle step position is the middle position; when the number of steps is an even number, the two middle planes are the middle position, and the height difference changes from the two steps to both sides.

[0008] According to an embodiment of the present invention, the step surface at the middle position of the step structure heat sink is parallel to the bottom surface.

[0009] According to an embodiment of the present invention, except for the step surface in the middle, the step surfaces on both sides of the step structure heat sink are at a certain angle to the bottom surface. When the number of steps is an even number, the two middle planes are set to be parallel planes.

[0010] According to an embodiment of the present invention, the angle between the step surface above the middle step surface and the bottom surface of the stepped structure heat sink is a negative value, and the angle between the step surface below the middle step surface and the bottom surface is a positive value.

[0011] Compared with the prior art, this application can achieve the following technical effects:

[0012] 1) The present invention adopts a stepped structure heat sink, and the height difference of each step surface is increasing, which can effectively avoid the fixed reflector on the step surface from blocking the adjacent laser beam, and can improve the laser power level transmitted to the focusing lens.

[0013] 2) The present invention uses a stepped structure with a certain tilt angle to rearrange the reflected laser beam, which can reduce the beam diameter of the beam before the focusing lens, while increasing the laser power density at the center of the lens in the beam and improving the coupling efficiency of the lens. The heat sink coupling process using this structure is easy to debug, effectively improves the laser beam combining efficiency, and can achieve higher power laser output. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0015] Figure 1 Schematic diagram of a heat sink with a stepped structure in one embodiment of the present invention;

[0016] Figure 2 is a side view schematic diagram of a heat sink with a stepped structure in one embodiment of the present invention;

[0017] Figure 3 It is a schematic diagram of the arrangement of a laser chip and an optical lens on a stepped heat sink in one embodiment of the present invention;

[0018] Among them, there are a laser chip 10 , a fast axis collimator 20 , a slow axis collimator 30 , and a reflector 40 . DETAILED DESCRIPTION

[0019] The following will describe the implementation methods of the present application in detail with the help of accompanying drawings and examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. Example

[0020] Figure 1 A schematic diagram of a semiconductor laser step structure heat sink according to an embodiment of the present invention is shown in the figure: a semiconductor laser step structure heat sink comprises: a step heat sink; a plurality of steps are arranged on the step heat sink, and the height difference of each step increases from the middle to both sides, effectively preventing the reflector arranged on the step surface from blocking the light beam reflected by the step surface on it, thereby improving the light beam transmission efficiency; the step surface at the middle position on the step heat sink is a parallel plane structure with the bottom surface; the step surfaces on both sides of the step heat sink except the step surface at the middle position are all plane structures with a certain angle to the bottom surface; the angle of the step surface above the middle step surface is a negative value, and the angle of the step surface below is a positive value.

[0021] Figure 2 This is a side view of a semiconductor laser step structure heat sink according to an embodiment of the present invention. In the figure, the step surface at the middle position of the step heat sink is parallel to the bottom surface; the upper step of the step surface at the middle position is at an angle of -α to the bottom surface; the lower step of the step surface at the middle position is at an angle of α to the bottom surface. The step surfaces on both sides are set so that the light beam is reflected by the step surfaces and converges to the central area of ​​the light spot.

[0022] Figure 3 This is a schematic diagram of the arrangement of the laser chip and optical lens on the step heat sink according to one embodiment of the present invention. The laser chip 10 is welded to the A end of the step heat sink. The light output by the laser chip 10 is compressed by the fast and slow axes of the laser light plate after passing through the fast axis collimator 20 and the slow axis collimator 30 thereafter. The compressed light spot is in the shape of a slender strip. The slender strip light beam passes through the reflector 40 arranged at a 45° angle at the B end of the step heat sink to achieve a 45° deflection in the transmission direction. Each step will deflect the laser beam to achieve a rearrangement of the light spot. After the rearrangement, the light spot, except for the light spot reflected by the step surface at the middle position, is in a horizontal light spot state. The rest of the light spots are inclined at a certain angle due to the inclination of the step surface. The rearrangement and superposition of the light spots effectively increase the laser power density in the center area of ​​the light spot, making the rearranged light spot more concentrated, reducing the spherical aberration of the focusing lens focusing on the rearranged light spot, and effectively improving the coupling efficiency of the optical fiber.

[0023] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the application concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present application, and should be within the scope of protection of the claims attached to the present application.

Claims

1. A semiconductor laser step structure heat sink, characterized in that: include: Step heat sink; The stepped heat sink is provided with a plurality of steps; the laser chips are respectively welded on the step surfaces; a fast axis collimator, a slow axis collimator and a reflector are sequentially provided on the light propagation path of the laser output from the laser chip; The height difference of each step surface of the step structure heat sink increases from the middle to both sides; the step surface in the middle of the step structure heat sink is parallel to the bottom plane; The remaining step surfaces of the step structure heat sink are all at a certain angle to the bottom plane; The angle between the step surface above the middle step surface of the step structure heat sink and the bottom surface is a negative value, and the angle between the step surface below the middle step surface and the bottom surface is a positive value.

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