Quasi-continuous array laser pump source and preparation method thereof

Abstract

The present invention provides a quasi-continuous array laser pump source and a preparation method thereof. The preparation method comprises: sintering a laser chip between each two adjacent heat sinks, with the light-emitting surface of the laser chip as the upper surface, and the side of the heat sink at the sintering position in contact with the side of the corresponding laser chip to obtain a first sample; sintering the lower surface of the first sample on the upper surface of the ceramic piece to obtain a quasi-continuous array laser pump source; performing a watertight treatment on one end face of the quasi-continuous array laser pump source and the exposed plane connected to both sides of the light-emitting upper surface of all laser chips, and filling the other end face of the quasi-continuous array laser pump source with a heat-conducting material; after the filling is completed, performing a heat curing treatment on the two end faces of the quasi-continuous array laser pump source and the watertightly treated plane connected to both sides of the light-emitting upper surface of all laser chips to obtain a final quasi-continuous array laser pump source. The present invention can effectively improve the heat dissipation efficiency of the quasi-continuous array laser pump source.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a quasi-continuous array laser pump source and a preparation method thereof. Background Art

[0002] High-power laser pump sources are widely used as pump sources for fiber lasers and solid-state lasers, enabling high-energy laser weapons and optoelectronic pod systems. Depending on the operating state of the pumped laser, laser pump sources can be categorized as continuous array laser pump sources and quasi-continuous array laser pump sources. Quasi-continuous array laser pump sources are achieved by welding arrays of high-power laser chips—"bars"—to a high-thermal-conductivity, low-roughness heat sink and corresponding semiconductor ceramics. Multiple bars are then connected in parallel to create a quasi-continuous array laser pump source.

[0003] Since the typical reverse bias voltage of a laser is 2V and the photoelectric efficiency of a bar is 50% to 60%, a large current (on the order of hundreds of amperes) must be applied to the laser pump source to achieve higher output power. Therefore, achieving rapid heat dissipation within the extremely small space of a quasi-continuous array laser pump source (cavity length on the order of mm, light-emitting area on the order of μm) becomes a key factor in stabilizing the laser's operating state and improving its photoelectric efficiency.

[0004] The traditional method for fabricating a quasi-continuous-wave array laser pump source involves machining a heat sink, then grinding, polishing, electroplating, and inspecting it to achieve a low roughness. Bars, each approximately one micron thick, are then sintered onto the heat sink and then welded to the ceramic. However, this method results in a mismatch between the bar thickness and the heat sink height, leading to air voids between the bar and the ceramic. This compromises heat dissipation and results in low heat dissipation efficiency, thus limiting the development of higher-power quasi-continuous-wave array laser pump sources. Summary of the Invention

[0005] The embodiment of the present invention provides a quasi-continuous array laser pump source and a preparation method thereof, so as to solve the problem of low heat dissipation efficiency of the existing quasi-continuous array laser pump source.

[0006] In a first aspect, an embodiment of the present invention provides a method for preparing a quasi-continuous array laser pump source, comprising: sintering a laser chip between each of two adjacent heat sinks, with the light-emitting surface of the laser chip serving as the upper surface, and with the side surfaces of the heat sinks at the sintering positions in contact with the side surfaces of the corresponding laser chips, to obtain a first sample;

[0007] Sintering the lower surface of the first sample to the upper surface of the ceramic to obtain a quasi-continuous array laser pump source; the light-emitting upper surface of the laser chip is away from the upper surface of the ceramic;

[0008] Performing watertight treatment on one end face of the quasi-continuous array laser pump source and the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips, and filling the other end face of the quasi-continuous array laser pump source with heat-conducting material;

[0009] After filling, the two end faces of the quasi-continuous array laser pump source and the watertight surfaces connected on both sides of the light-emitting upper surfaces of all laser chips are thermally cured to obtain the final quasi-continuous array laser pump source.

[0010] In a possible implementation, when a laser chip is sintered between each two adjacent heat sinks, the light-emitting upper surface of each laser chip is on the same horizontal plane as the upper surfaces of the two adjacent heat sinks.

[0011] In a possible implementation, the watertight treatment of one end face of the quasi-continuous array laser pump source and the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips includes:

[0012] One end face of the quasi-continuous array laser pump source and the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips are sealed with filter paper.

[0013] In a possible implementation, the thermally conductive material includes: carbon nanotube powder, graphene fluid, or graphene liquid.

[0014] In one possible implementation, the two end faces of the quasi-continuous array laser pump source and the watertightly connected planes on both sides of the light-emitting upper surfaces of all laser chips are subjected to a heat curing treatment, and the heat curing treatment includes:

[0015] The two end faces of the quasi-continuous array laser pump source and the watertightly connected planes on both sides of the light-emitting upper surfaces of all laser chips are sealed and solidified using thermosetting glue.

[0016] In a possible implementation, the heat sink includes a tungsten copper heat sink or a silicon carbide heat sink.

[0017] In a possible implementation, the ceramic tile includes an aluminum nitride ceramic tile or an aluminum oxide ceramic tile.

[0018] In a possible implementation, the thermosetting adhesive includes UV adhesive.

[0019] In a second aspect, an embodiment of the present invention provides a quasi-continuous array laser pump source, the quasi-continuous array laser pump source comprising: a heat sink, a laser chip, a ceramic piece, a thermosetting adhesive, and a thermal conductive material;

[0020] Each two adjacent heat sinks are respectively connected to a laser chip, and the light emitting surface of the laser chip is the upper surface;

[0021] The lower surfaces of all heat sinks are connected to the upper surface of the ceramic tile;

[0022] The thermosetting adhesive is respectively provided on the two end surfaces formed between every two adjacent heat sinks, and on the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips;

[0023] The heat-conducting materials are respectively arranged in a free space formed by each laser chip, two heat sinks adjacent thereto, the ceramic sheet and the thermosetting adhesive.

[0024] In a possible implementation, the light-emitting upper surface of each laser chip is on the same horizontal plane as the upper surfaces of two adjacent heat sinks.

[0025] An embodiment of the present invention provides a quasi-continuous array laser pump source and a preparation method thereof. The preparation method comprises the following steps: sintering a laser chip between each two adjacent heat sinks, with the light-emitting surface of the laser chip serving as the upper surface and the side surfaces of the heat sinks at the sintering position in contact with the side surfaces of the corresponding laser chips, to obtain a first sample; sintering the lower surface of the first sample to the upper surface of a ceramic tile to obtain a quasi-continuous array laser pump source; performing a watertight treatment on one end face of the quasi-continuous array laser pump source and an exposed plane connected to both sides of the light-emitting upper surfaces of all the laser chips, and filling the other end face of the quasi-continuous array laser pump source with a heat-conducting material; after the filling is completed, performing a heat curing treatment on both end faces of the quasi-continuous array laser pump source and the watertightly treated plane connected to both sides of the light-emitting upper surfaces of all the laser chips to obtain a final quasi-continuous array laser pump source. Among them, by filling the free space formed by the heat sink, laser chip, ceramic plate, and the two end faces and planes subjected to heat curing treatment with thermal conductive material, the heat generated by the laser chip can be dissipated through the heat sink and thermal conductive material in contact with it, which can effectively improve the heat dissipation efficiency of the quasi-continuous array laser pump source. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 these drawings without paying any creative work.

[0027] Figure 1 This is a flow chart of a method for preparing a quasi-continuous array laser pump source provided by an embodiment of the present invention;

[0028] Figure 21 is a schematic structural diagram of a quasi-continuous array laser pump source provided by an embodiment of the present invention;

[0029] Figure 3 is a cross-sectional view of a quasi-continuous array laser pump source provided by an embodiment of the present invention in a top-down direction;

[0030] Figure 4 is a cross-sectional view of a quasi-continuous array laser pump source provided by an embodiment of the present invention in the main viewing direction;

[0031] Figure 5 It is a cross-sectional view of a quasi-continuous array laser pump source provided by an embodiment of the present invention in the left-view direction. DETAILED DESCRIPTION

[0032] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0033] In order to illustrate the technical solution of the present invention, specific embodiments are provided below.

[0034] The following is a detailed description of the implementation of the present invention with reference to the accompanying drawings:

[0035] Figure 1 The following is a flowchart of a method for preparing a quasi-continuous array laser pump source provided by an embodiment of the present invention, as detailed below:

[0036] Step 101 , sintering a laser chip between each two adjacent heat sinks, with the light-emitting surface of the laser chip as the upper surface, and the side surfaces of the heat sinks at the sintering positions in contact with the side surfaces of the corresponding laser chips, to obtain a first sample.

[0037] Optionally, a laser chip may be sintered between every two adjacent heat sinks using gold-tin solder (eg, Au80Sn).

[0038] See Figure 2 、 Figure 3 、 Figure 4 and Figure 5 The side surfaces of the heat sink 21 at the sintering position are in contact with the corresponding side surfaces of the laser chip 22. The laser chip 22 is typically a long strip. When sintering the laser chip 22, the side surfaces along the length of the laser chip 22 can be in contact with the side surfaces of the heat sink 21 to increase the heat dissipation contact area. Figure 2-5This figure is merely an example and does not specifically limit the number of laser chips 22 and the number of heat sinks 21 .

[0039] Optionally, when a laser chip 22 is sintered between each two adjacent heat sinks 21 , the light-emitting upper surface of each laser chip 22 is on the same horizontal plane as the upper surfaces of the two adjacent heat sinks 21 .

[0040] To prevent the heat sink 21 from blocking the laser emission path, when sintering the laser chip 22 , the light-emitting upper surface of the laser chip 22 and the upper surfaces of two adjacent heat sinks 21 may be arranged on the same horizontal plane.

[0041] Optionally, the heat sink 21 may include a tungsten copper heat sink or a silicon carbide heat sink. The heat sink 21 may also be made of other highly thermally conductive, weldable materials, which is not specifically limited in the embodiment of the present invention.

[0042] Step 102 , sintering the lower surface of the first sample to the upper surface of the ceramic piece 23 to obtain a quasi-continuous array laser pump source; the light-emitting upper surface of the laser chip 22 is away from the upper surface of the ceramic piece 23 .

[0043] The light-emitting surface of the laser chip 22 is used as the upper surface of the first sample, and the lower surface of the first sample is sintered to the upper surface of the ceramic piece 23 to obtain a quasi-continuous array laser pump source.

[0044] Optionally, the ceramic tile 23 may include an aluminum nitride ceramic tile or an aluminum oxide ceramic tile.

[0045] Step 103 , perform watertight treatment on one end face of the quasi-continuous array laser pump source and the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips, and fill the other end face of the quasi-continuous array laser pump source with heat conductive material 24 .

[0046] See also Figure 3 To achieve better heat dissipation, the length of the heat sink 21 is usually greater than the length of the laser chip 22. The "exposed surface connected to both sides of the light-emitting upper surface of all laser chips" here actually refers to the remaining exposed surface on the upper surface of the first sample that is not blocked by the laser chip 22.

[0047] Optionally, a watertight treatment is performed on one end face of the continuous array laser pump source and the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips 22, including:

[0048] One end face of the quasi-continuous array laser pump source and the exposed planes connected to both sides of the light-emitting upper surfaces of all the laser chips 22 are sealed with filter paper.

[0049] Filter paper is used to seal one end face of the quasi-continuous array laser pump source and the exposed plane connected to both sides of the light-emitting upper surface of all laser chips 22, so that the free space formed by the heat sink 21, laser chip 22, ceramic tile 23 and filter paper can be filled with thermal conductive material 24 from the other end face.

[0050] Optionally, the thermal conductive material 24 includes carbon nanotube powder, graphene fluid or graphene liquid.

[0051] In practical applications, a spray gun with a diameter of less than 100 microns can be used to blow carbon nanotube powder into the free space formed by the heat sink, laser chip, ceramic sheet and filter paper; or a dropper can be used to drop graphene fluid or graphene liquid into the free space.

[0052] Step 104, after filling, heat curing is performed on the two end faces of the quasi-continuous array laser pump source and the watertight planes connected on both sides of the light-emitting upper surfaces of all laser chips to obtain the final quasi-continuous array laser pump source.

[0053] Optionally, heat curing is performed on both end faces of the continuous array laser pump source and the watertight surfaces connected on both sides of the light-emitting upper surfaces of all laser chips, including:

[0054] The two end faces of the quasi-continuous array laser pump source and the watertight surfaces connected on both sides of the light-emitting upper surfaces of all laser chips are sealed and cured using thermosetting adhesive 25 .

[0055] The free space formed by the heat sink 21, laser chip 22, ceramic tile 23, and filter paper is completely filled with thermally conductive material 24. After filling, the two end faces of the quasi-continuous laser array pump source and the watertight surfaces connecting the upper light-emitting surfaces of all laser chips are sealed and cured using thermosetting adhesive 25. This completes the quasi-continuous laser array pump source.

[0056] Optionally, the thermosetting adhesive 25 may include UV adhesive.

[0057] In an embodiment of the present invention, a first sample is obtained by sintering a laser chip 22 between each two adjacent heat sinks 21, with the light-emitting surface of the laser chip 22 as the upper surface and the side surfaces of the heat sink 21 at the sintering position in contact with the side surfaces of the corresponding laser chip 22; the lower surface of the first sample is sintered on the upper surface of the ceramic piece 23 to obtain a quasi-continuous array laser pump source; one end face of the aligned continuous array laser pump source and the exposed plane connected to both sides of the light-emitting upper surfaces of all the laser chips 22 are subjected to watertight treatment, and the other end face of the quasi-continuous array laser pump source is filled with heat-conducting material 24; after the filling is completed, the two end faces of the aligned continuous array laser pump source and the watertight plane connected to both sides of the light-emitting upper surfaces of all the laser chips are subjected to heat curing treatment to obtain a final quasi-continuous array laser pump source. Among them, by filling the free space formed by the heat sink 21, the laser chip 22, the ceramic piece 23, and the two end faces and the plane subjected to heat curing treatment with thermal conductive material 24, the heat generated by the laser chip 22 can be dissipated through the heat sink 21 and the thermal conductive material 24 in contact with it, which can effectively improve the heat dissipation efficiency of the quasi-continuous array laser pump source; and, the resistivity of the carbon nanotube powder, graphene fluid or graphene liquid is relatively large, which can effectively reduce the probability of breakdown short circuit; at the same time, when filling the thermal conductive material 24, a narrow-bore spray gun or dropper can be used for filling. Since the light-emitting surface of the quasi-continuous array laser pump source is located on the upper surface, and the thermal conductive material 24 is filled below the laser chip 22, when a narrow-bore spray gun or dropper is used to fill the thermal conductive material 24, the light-emitting surface will not be contaminated, and the yield rate is higher.

[0058] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0059] Corresponding to the preparation method of the quasi-continuous array laser pump source described in the above embodiment, Figure 2 A schematic structural diagram of a quasi-continuous array laser pump source provided by an embodiment of the present invention is shown. Figure 3-Figure 5 The cross-sectional views of the quasi-continuous array laser pump source provided by the embodiment of the present invention in various directions are shown respectively.

[0060] The quasi-continuous array laser pump source includes a heat sink 21 , a laser chip 22 , a ceramic plate 23 , a thermosetting adhesive 25 and a heat conducting material 24 .

[0061] Each adjacent two heat sinks 21 are respectively connected to a laser chip 22, and the light emitting surface of the laser chip 22 is the upper surface;

[0062] The lower surface of all heat sinks 21 is connected to the upper surface of the ceramic tile 23;

[0063] Thermosetting adhesive 25 is respectively provided on both end surfaces formed between each two adjacent heat sinks 21 and on the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips 22;

[0064] The heat-conducting material 24 is respectively disposed in the free space formed by each laser chip 22 , the two adjacent heat sinks 21 , the ceramic plate 23 and the thermosetting adhesive 25 .

[0065] Optionally, the light-emitting upper surface of each laser chip 22 is on the same horizontal plane as the upper surfaces of two adjacent heat sinks 21 .

[0066] The beneficial effects of the quasi-continuous array laser pump source in the embodiment of the present invention are:

[0067] 1. High heat dissipation efficiency. Compared with the technical solution of the prior art in which an air cavity exists between the laser chip and the ceramic tile, the embodiment of the present invention sets the thermal conductive material 24 in the free space formed by the heat sink 21, the laser chip 22, the ceramic tile 23 and the thermosetting adhesive 25. The heat generated by the laser chip 22 can be dissipated through the heat sink 21 and the thermal conductive material 24 in contact with it, which can effectively improve the heat dissipation efficiency of the quasi-continuous array laser pump source;

[0068] 2. Low probability of breakdown short circuit. The resistivity of carbon nanotube powder, graphene fluid or graphene liquid is relatively high, which can effectively reduce the probability of breakdown short circuit;

[0069] 3. No contamination of the light-emitting surface. Since the light-emitting surface of the quasi-continuous array laser pump source is located on the upper surface, and the heat-conducting material 24 is filled under the laser chip 22, the light-emitting surface will not be contaminated, and the yield rate is higher.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention 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 make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a quasi-continuous array laser pump source, characterized in that: include: Sintering a laser chip between each two adjacent heat sinks, with the light-emitting surface of the laser chip serving as the upper surface, and the side surfaces of the heat sinks at the sintering positions in contact with the side surfaces of the corresponding laser chips, to obtain a first sample; Sintering the lower surface of the first sample to the upper surface of the ceramic to obtain a quasi-continuous array laser pump source; the light-emitting upper surface of the laser chip is away from the upper surface of the ceramic; Performing watertight treatment on one end face of the quasi-continuous array laser pump source and the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips, and filling the other end face of the quasi-continuous array laser pump source with heat-conducting material; After filling, the two end faces of the quasi-continuous array laser pump source and the watertight surfaces connected on both sides of the light-emitting upper surfaces of all laser chips are thermally cured to obtain the final quasi-continuous array laser pump source.

2. The method for preparing a quasi-continuous array laser pump source according to claim 1, wherein: When a laser chip is sintered between each two adjacent heat sinks, the light-emitting upper surface of each laser chip is on the same horizontal plane as the upper surfaces of the two adjacent heat sinks.

3. The method for preparing a quasi-continuous array laser pump source according to claim 1, wherein: The step of performing watertight treatment on one end face of the quasi-continuous array laser pump source and the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips comprises: One end face of the quasi-continuous array laser pump source and the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips are sealed with filter paper.

4. The method for preparing a quasi-continuous array laser pump source according to claim 1, wherein: The thermal conductive material includes: carbon nanotube powder, graphene fluid or graphene liquid.

5. The method for preparing a quasi-continuous array laser pump source according to claim 1, wherein: The two end faces of the quasi-continuous array laser pump source and the watertightly connected planes on both sides of the light-emitting upper surfaces of all laser chips are subjected to heat curing treatment, and the heat curing treatment includes: The two end faces of the quasi-continuous array laser pump source and the watertightly connected planes on both sides of the light-emitting upper surfaces of all laser chips are sealed and solidified using thermosetting glue.

6. The method for preparing a quasi-continuous array laser pump source according to claim 1, wherein: The heat sink comprises a tungsten copper heat sink or a silicon carbide heat sink.

7. The method for preparing a quasi-continuous array laser pump source according to claim 1, wherein: The ceramic tile includes an aluminum nitride ceramic tile or an aluminum oxide ceramic tile.

8. The method for preparing a quasi-continuous array laser pump source according to claim 5, wherein: The thermosetting adhesive includes UV adhesive.

9. A quasi-continuous array laser pump source, characterized in that: The quasi-continuous array laser pump source is prepared according to the preparation method of claims 1 to 8, wherein the quasi-continuous array laser pump source comprises: a heat sink, a laser chip, a ceramic chip, a thermosetting adhesive, and a thermal conductive material; Each two adjacent heat sinks are respectively connected to a laser chip, and the light emitting surface of the laser chip is the upper surface; The lower surfaces of all heat sinks are connected to the upper surface of the ceramic tile; The thermosetting adhesive is respectively provided on the two end surfaces formed between every two adjacent heat sinks, and on the exposed planes connected to both sides of the light-emitting upper surfaces of all laser chips; The heat-conducting materials are respectively arranged in a free space formed by each laser chip, two heat sinks adjacent thereto, the ceramic sheet and the thermosetting adhesive.

10. The quasi-continuous array laser pump source according to claim 9, characterized in that: The light-emitting upper surface of each laser chip is on the same horizontal plane as the upper surfaces of two adjacent heat sinks.

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