Device and method for testing divergence angle and light spot size of laser module

Abstract

The invention discloses a laser module divergence angle and light spot size testing device and method, belongs to the technical field of divergence angle and light spot testing, and solves the problems that in the prior art, the station space is large, the laser module divergence angle and light spot size testing device cannot be suitable for various lasers, and high-power and large-light-spot light beams are difficult to measure. A laser module, a testing device and a power meter are sequentially arranged on the surface of the optical platform in the axis direction, and a collimated laser beam emitted by the laser module enters the power meter after passing through the testing device. According to the invention, the laser module, the testing device and the power meter are integrally arranged, so that a large station space required for measuring a laser divergence angle and a light spot size by a knife edge method is reduced; the positions of the fast axis and the slow axis are adjusted according to different powers and then are measured, and measurement of divergence angles and light spot sizes of different types of laser modules is met; the device is not influenced by a light receiving aperture and a damage threshold value, and can measure a high-power and large-light-spot light beam.

Description

Technical Field

[0001] The present invention belongs to the technical field of divergence angle and light spot testing, and in particular, relates to a device and method for testing the divergence angle and light spot size of a laser module. Background Art

[0002] With the development of semiconductor laser technology, semiconductor lasers are being used more and more widely, and the power and beam quality requirements of semiconductor lasers are becoming more stringent. Lasers with higher power, higher beam quality and smaller divergence angles are increasingly needed by the market. At present, the FAC and SAC adjustment technology of semiconductor lasers is becoming more and more advanced, and the installation accuracy of FAC and SAC has also been greatly improved. At the same time, the requirements for the divergence angle and spot size of semiconductor lasers after FAC and SAC collimation are also becoming more stringent. Therefore, a high-precision method is needed to test the divergence angle and spot size of semiconductor lasers. Common divergence angle test methods include the knife-edge method and the CCD method. The knife-edge method requires repeated and multi-position measurement of laser energy, which takes a long time and has complicated steps. In addition, due to mechanical errors, manual measurement errors and other factors, the knife-edge method cannot accurately measure small divergence angles and spot sizes of light beams after FAC and SAC. The CCD method is limited by the light receiving aperture and damage threshold of the CCD and cannot measure high-power, large-spot light beams. Therefore, it is necessary to design a test device and method that can accurately measure the divergence angle and spot size of the laser after FAC and SAC collimation. Summary of the invention

[0003] The purpose of the present invention is to address the deficiencies in the prior art and to provide a laser module divergence angle and spot size testing device and method which has a small workstation space, is suitable for various types of lasers, and can effectively measure high-power, large-spot light beams.

[0004] In order to achieve the above technical objectives, the technical solutions adopted by the laser module divergence angle and spot size testing device and method of the present invention are as follows: A laser module divergence angle and spot size testing device comprises an optical platform, wherein the surface of the optical platform is provided with a laser module, a testing device and a power meter in sequence along an axial direction, wherein a collimated laser beam emitted by the laser module is incident on the power meter after passing through the testing device, wherein the testing device comprises a shell, wherein a light inlet is provided in the middle of the front end of the shell, and a light outlet corresponding to the light inlet is provided at the rear end, wherein the light inlet and the light outlet are located on the same axis, wherein a first slow axis blade edge and a second slow axis blade edge are provided on both sides of the light inlet, respectively, wherein a first fast axis blade edge and a second fast axis blade edge perpendicular to the first slow axis blade edge are provided outside the first slow axis blade edge and the second slow axis blade edge, and wherein a total reflection mirror group and a mirror stand provided outside a reflection path formed by the total reflection mirror group are further provided in the shell.

[0005] Preferably, the laser module comprises a mounting base arranged on the surface of the optical platform, and a laser is arranged on the surface of the mounting base.

[0006] Preferably, the mounting base is a height-adjustable water-permeable base, which provides water cooling for the laser.

[0007] Preferably, the path length of the laser beam sequentially passing through the light inlet, the total reflection mirror group and the light outlet is 1 m.

[0008] Preferably, an upper cover is provided on the top of the shell, and a handle is provided on the surface of the upper cover.

[0009] Preferably, the first slow-axis cutting edge is parallel to the second slow-axis cutting edge left and right and extends in the vertical direction, and the first fast-axis cutting edge is parallel to the second fast-axis cutting edge top and bottom and extends in the horizontal direction.

[0010] Preferably, the total reflection mirror group includes two groups of total reflection mirrors arranged in the shell, the two groups of total reflection mirrors include a total reflection mirror combination A and a total reflection mirror combination B which are symmetrically arranged front to back, the total reflection mirror combination A includes a total reflection mirror unit A and a total reflection mirror unit B which are symmetrically arranged front to back, the total reflection unit A includes a first total reflection mirror and a second total reflection mirror which are parallel to the left and right and are arranged at an obtuse angle to the horizontal direction, the total reflection unit B includes a third total reflection mirror and a fourth total reflection mirror which are parallel to the left and right and are arranged at an acute angle to the horizontal direction, the total reflection mirror combination B includes a total reflection mirror unit C and a total reflection mirror unit D which are symmetrically arranged front to back, the total reflection unit C includes a fifth total reflection mirror and a sixth total reflection mirror which are parallel to the left and right and are arranged at an obtuse angle to the horizontal direction, and the total reflection unit D includes a seventh total reflection mirror and an eighth total reflection mirror which are parallel to the left and right and are arranged at an acute angle to the horizontal direction.

[0011] A method for testing the divergence angle of a laser module comprises the following steps: S1 Assume that the power meter measures the starting laser power as 100W, and requires the measurement of the divergence angle of the laser power at 100% energy. Adjust the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance to ensure that the power of the power meter remains unchanged. Try to reduce the distance between the first slow-axis blade edge and the second slow-axis blade edge. After determining the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance, also determine the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light exit. After the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance and the light exit are determined, measure the distance between the first slow-axis blade edge and the second slow-axis blade edge at the light entrance and the light exit, which are D1 (mm) and D2 (mm) respectively. The slow-axis divergence angle (mrd) is [D2 (mm) - D1 (mm)] / 1m; S2 According to step S1, obtain the fast axis divergence angle; A method for testing the spot size of a laser module comprises the following steps: S1 Remove the second total reflection mirror and the seventh total reflection mirror, move the first slow axis knife edge, the second slow axis knife edge, the first fast axis knife edge and the second fast axis knife edge at the light inlet and the light outlet to the edge, ensure that the light inlet and the light outlet are not blocked, adjust the height of the mounting base, make the collimated light spot of the laser pass through the center of the light inlet, pass through the shell, and accurately irradiate the target surface of the power meter; S2 Assume that the power meter measures the laser power as 100W, and requires to measure the spot size at 100% laser power. Adjust the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance. When the power of the power meter remains unchanged, try to reduce the distance between the first slow-axis blade edge and the second slow-axis blade edge. After determining the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance, measure the distance between the first slow-axis blade edge and the second slow-axis blade edge at the light entrance, and obtain the slow-axis spot size D3 (mm). S3 According to step S1, the fast axis spot size is obtained.

[0012] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, the laser module, the test device and the power meter are arranged as a whole, which reduces the large workstation space required for the knife-edge method to measure the laser divergence angle and the spot size; the fast and slow axis positions are adjusted according to different powers and then measured to meet the measurement of the divergence angle and the spot size of different types of laser modules; it is not affected by the light receiving aperture and the damage threshold, and can measure high-power, large-spot light beams. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of a laser divergence angle and spot size testing device in the prior art; Figure 2 It is a schematic diagram of the structure of the present invention; Figure 3 It is a structural schematic diagram of the testing device in the present invention; Figure 4 It is a schematic diagram of the internal structure of the testing device in the present invention; Figure 5 It is the divergence angle measurement optical path diagram in the present invention; Figure 6 This is the optical path diagram for measuring the light spot size in the present invention.

[0014] In the figure: 1. Optical platform; 2. Power meter; 3. Housing; 4. Light inlet; 5. Light outlet; 6. First slow axis edge; 7. Second slow axis edge; 8. First fast axis edge; 9. Second fast axis edge; 10. Mirror stand; 11. Mounting base; 12. Laser; 13. Upper cover; 14. Handle; 151. The first total reflection mirror; 152. The second total reflection mirror; 153. The third total reflection mirror; 154. The fourth total reflection mirror; 155. The fifth total reflection mirror; 156. The sixth total reflection mirror; 157. The seventh total reflection mirror; 158. The eighth total reflection mirror. DETAILED DESCRIPTION

[0015] The invention is further described below in conjunction with the accompanying drawings and specific embodiments: like Figure 1 As shown, in the prior art, when testing the divergence angle and spot size of the laser after FAC and SAC collimation, the blade is cut horizontally at at least two positions of the light beam along a direction perpendicular to the light beam. When cutting each position, the blade is slowly moved to record the change process of the light beam, and the position information of the blade in the two cases where the light beam is just blocked and completely blocked is recorded, and the beam divergence angle and spot size are obtained through calculation. However, in this method, the laser emission spot needs to pass through a beam expansion and collimation system, and the manufacturing cost of the beam expansion and collimation system is relatively high. At the same time, the workstation space required for the overall device is relatively large, and the construction process is cumbersome. In addition, when measuring the blade, the divergence angle and spot size need to be calculated, and the overall calculation process is complicated.

[0016] like Figure 2 — Figure 6 As shown, a laser module divergence angle and spot size testing device comprises an optical platform 1, wherein the surface of the optical platform 1 is provided with a laser module, a testing device and a power meter 2 in sequence along the axial direction, wherein the collimated laser beam emitted by the laser module is incident on the power meter 2 after passing through the testing device, wherein the laser module comprises a mounting base 11 arranged on the surface of the optical platform 1, wherein a laser 12 is arranged on the surface of the mounting base 11, wherein the mounting base 11 is a water-passing base with adjustable height, and wherein the laser 12 is provided with water cooling, wherein the testing device comprises a shell 3, wherein a light inlet 4 is provided at the middle of the front end of the shell 3, and a light outlet 5 corresponding to the light inlet 4 is provided at the rear end, wherein the light inlet 4 and the light outlet 5 are located on the same axis, wherein a first slow axis blade 6 and a second slow axis blade 7 are provided on both sides of the light inlet 4, wherein a first fast axis blade 8 and a second fast axis blade 9 perpendicular to the first slow axis blade 6 and the second slow axis blade 7 are provided on the outer sides thereof, wherein a total reflection mirror group and a mirror stand 10 arranged on the outer side of the reflection path formed by the total reflection mirror group are further provided in the shell 3. By adjusting the height of the mounting base 11 , the collimated light spot of the laser module passes through the center of the light inlet 4 , and the power meter 2 is placed at the light outlet 5 to ensure that the output light spot is irradiated on the target surface of the power meter 2 .

[0017] In the present invention, the path length of the laser beam passing through the light inlet 4, the total reflection mirror group and the light outlet 5 is 1 m. By setting the length of the path through which the laser beam passes, not only the station requirements are reduced, but also the tedious multiple calculations in the knife-edge method are avoided.

[0018] In the present invention, a cover 13 is disposed on the top of the housing 3, and a handle 14 is disposed on the surface of the cover 13. By providing the handle, the whole device is easy to carry.

[0019] In the present invention, the first slow axis blade 6 is parallel to the second slow axis blade 7 and extends in the vertical direction, the first fast axis blade 8 is parallel to the second fast axis blade 9 and extends in the horizontal direction, the total reflection mirror group includes two groups of total reflection mirrors arranged in the housing 3, the two groups of total reflection mirrors include a total reflection mirror combination A and a total reflection mirror combination B that are symmetrically arranged front and back, the total reflection mirror combination A includes a total reflection mirror unit A and a total reflection mirror unit B that are symmetrically arranged front and back, the total reflection unit A includes a first total reflection mirror parallel to the left and right that is arranged at an obtuse angle to the horizontal direction Mirror 151 and a second total reflection mirror 152, the total reflection unit B includes a third total reflection mirror 153 and a fourth total reflection mirror 154 which are parallel to the left and right and are set at an acute angle to the horizontal direction, the total reflection mirror combination B includes a total reflection mirror unit C and a total reflection mirror unit D which are symmetrically arranged front to back, the total reflection unit C includes a fifth total reflection mirror 155 and a sixth total reflection mirror 156 which are parallel to the left and right and are set at an obtuse angle to the horizontal direction, the total reflection unit D includes a seventh total reflection mirror 157 and an eighth total reflection mirror 158 which are parallel to the left and right and are set at an acute angle to the horizontal direction.

[0020] A method for testing the divergence angle of a laser module comprises the following steps: S1 Assume that the power meter measures the starting laser power as 100W, and requires the measurement of the divergence angle of the laser power at 100% energy. Adjust the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance to ensure that the power of the power meter remains unchanged. Try to reduce the distance between the first slow-axis blade edge and the second slow-axis blade edge. After determining the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance, also determine the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light exit. After the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance and the light exit are determined, measure the distance between the first slow-axis blade edge and the second slow-axis blade edge at the light entrance and the light exit, which are D1 (mm) and D2 (mm) respectively. The slow-axis divergence angle (mrd) is [D2 (mm) - D1 (mm)] / 1m; S2 According to step S1, obtain the fast axis divergence angle; A method for testing the spot size of a laser module comprises the following steps: S1 Remove the second total reflection mirror and the seventh total reflection mirror, move the first slow axis edge, the second slow axis edge, the first fast axis edge and the second fast axis edge at the light inlet and the light outlet to the edge, ensure that the light inlet and the light outlet are not blocked, adjust the height of the mounting base, make the collimated light spot of the laser pass through the center of the light inlet, pass through the shell, and accurately illuminate the target surface of the power meter.

[0021] S2 Assume that the power meter measures the laser power as 100W, and requires to measure the spot size at 100% laser power. Adjust the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance. When the power of the power meter remains unchanged, try to reduce the distance between the first slow-axis blade edge and the second slow-axis blade edge. After determining the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance, measure the distance between the first slow-axis blade edge and the second slow-axis blade edge at the light entrance, and obtain the slow-axis spot size D3 (mm). S2 According to step S1, the fast axis spot size is obtained.

[0022] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. All equivalent changes and modifications in the shape, structure, characteristics and spirit of the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A laser module divergence angle and spot size testing device, comprising an optical platform, characterized in that: The surface of the optical platform is provided with a laser module, a test device and a power meter in sequence along the axial direction; the collimated laser beam emitted by the laser module passes through the test device and is incident on the power meter; the test device comprises a shell, a light inlet is provided in the middle of the front end of the shell, a light outlet corresponding to the light inlet is provided at the rear end, the light inlet and the light outlet are located on the same axis, a first slow-axis blade edge and a second slow-axis blade edge are provided on both sides of the light inlet, a first fast-axis blade edge and a second fast-axis blade edge perpendicular to the first slow-axis blade edge are provided outside the first slow-axis blade edge and the second slow-axis blade edge, and a total reflection mirror group and a mirror stand provided outside the reflection path formed by the total reflection mirror group are further provided in the shell.

2. The laser module divergence angle and spot size testing device according to claim 1, characterized in that: The laser module comprises a mounting base arranged on the surface of the optical platform, and a laser is arranged on the surface of the mounting base.

3. The laser module divergence angle and spot size testing device according to claim 2, characterized in that: The mounting base is a height-adjustable water-permeable base, which provides water cooling for the laser.

4. The laser module divergence angle and spot size testing device according to claim 1, characterized in that: The path length of the laser beam passing through the light inlet, the total reflection mirror group and the light outlet in sequence is 1 m.

5. The laser module divergence angle and spot size testing device according to claim 1, characterized in that: An upper cover is arranged on the top of the shell body, and a handle is arranged on the surface of the upper cover.

6. The laser module divergence angle and spot size testing device according to claim 1, characterized in that: The first slow-axis cutting edge is parallel to the second slow-axis cutting edge left and right and extends in the vertical direction, and the first fast-axis cutting edge is parallel to the second fast-axis cutting edge top and bottom and extends in the horizontal direction.

7. The laser module divergence angle and spot size testing device according to claim 1, characterized in that: The total reflection mirror group includes two groups of total reflection mirrors arranged in a shell, the two groups of total reflection mirrors include a total reflection mirror combination A and a total reflection mirror combination B which are symmetrically arranged front to back, the total reflection mirror combination A includes a total reflection mirror unit A and a total reflection mirror unit B which are symmetrically arranged front to back, the total reflection unit A includes a first total reflection mirror and a second total reflection mirror which are parallel to the left and right and are arranged at an obtuse angle to the horizontal direction, the total reflection unit B includes a third total reflection mirror and a fourth total reflection mirror which are parallel to the left and right and are arranged at an acute angle to the horizontal direction, the total reflection mirror combination B includes a total reflection mirror unit C and a total reflection mirror unit D which are symmetrically arranged front to back, the total reflection unit C includes a fifth total reflection mirror and a sixth total reflection mirror which are parallel to the left and right and are arranged at an obtuse angle to the horizontal direction, and the total reflection unit D includes a seventh total reflection mirror and an eighth total reflection mirror which are parallel to the left and right and are arranged at an acute angle to the horizontal direction.

8. A method for testing the divergence angle of a laser module, characterized in that: The following steps are involved: S1 Assume that the power meter measures the starting laser power as 100W, and requires the measurement of the divergence angle of the laser power at 100% energy. Adjust the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance to ensure that the power of the power meter remains unchanged. Try to reduce the distance between the first slow-axis blade edge and the second slow-axis blade edge. After determining the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance, also determine the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light exit. After the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance and the light exit are determined, measure the distance between the first slow-axis blade edge and the second slow-axis blade edge at the light entrance and the light exit, which are D1 (mm) and D2 (mm) respectively. The slow-axis divergence angle (mrd) is [D2 (mm) - D1 (mm)] / 1m; S2 According to step S1, obtain the fast axis divergence angle; A method for testing the spot size of a laser module comprises the following steps: S1 Remove the second total reflection mirror and the seventh total reflection mirror, move the first slow axis knife edge, the second slow axis knife edge, the first fast axis knife edge and the second fast axis knife edge at the light inlet and the light outlet to the edge, ensure that the light inlet and the light outlet are not blocked, adjust the height of the mounting base, make the collimated light spot of the laser pass through the center of the light inlet, pass through the shell, and accurately irradiate the target surface of the power meter; S2 Assume that the power meter measures the laser power as 100W, and requires to measure the spot size at 100% laser power. Adjust the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance. When the power of the power meter remains unchanged, try to reduce the distance between the first slow-axis blade edge and the second slow-axis blade edge. After determining the positions of the first slow-axis blade edge and the second slow-axis blade edge at the light entrance, measure the distance between the first slow-axis blade edge and the second slow-axis blade edge at the light entrance, and obtain the slow-axis spot size D3 (mm). S3 According to step S1, the fast axis spot size is obtained.

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