Laser chip divergence angle testing device
By arraying laser chip divergence angle testing devices with multiple PD chips on a PCB board, the problem of expensive equipment and long testing time in the prior art is solved, and fast and accurate divergence angle testing is achieved.
Patent Information
- Application Number
- CN202421535405.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-01
- Publication Date
- 2025-04-22
- Estimated Expiration
- 2034-07-01
AI Technical Summary
In the prior art, when testing the divergence angle of laser chips, there are problems such as expensive equipment and long testing time.
A laser chip divergence angle test device is designed, and a multi-PD chip is arranged on a PCB board and the divergence angle is calculated using formula (N-1)×2° to achieve rapid testing.
The device does not require expensive spot testers or coupled fibers, the test time is short and the test accuracy can reach 2°, meeting the divergence angle testing requirements of conventional laser chips.
Smart Images
Figure CN222784306U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of laser chip divergence angle testing, in particular to a laser chip divergence angle testing device. Background Art
[0002] There are generally two methods for testing the divergence angle of laser chips:
[0003] 1) Use a spot tester to test the spot diameter at different distances. According to tg (divergence angle) = (Rr) / L, R is the radius of the distant spot, r is the radius of the near spot, and L is the distance difference between the distant and near spots, the divergence angle of the laser chip can be tested. The disadvantage is that the spot tester is very expensive.
[0004] 2) Make a circular disk (with angle measurement scale lines), and couple the optical fiber or PD chip along the circumference. The angle scale lines recorded in the absence of light (or when the light suddenly decreases a lot) are the divergence angles. The disadvantage is that the coupling is very slow and time-consuming. Utility Model Content
[0005] The technical problem to be solved by the utility model is to provide a laser chip divergence angle testing device to overcome the deficiencies in the above-mentioned prior art.
[0006] The utility model solves the above-mentioned technical problem with a technical solution as follows: a laser chip divergence angle test device, comprising: a PCB board, on which a plurality of PD chips are pasted in a passive patch manner along a circumferential array, the side of the PD chip close to the center of the circle is a light-collecting surface, and the PD chip is electrically connected to the PCB board; the light strip of the laser chip to be tested is located at the center of the PD chip array and is electrically connected to the PCB board.
[0007] The beneficial effects of the utility model are: lighting up the laser chip, observing which PD chip starts to have no photocurrent (or the photocurrent suddenly drops a lot) in subsequent PD chips, and calculating the horizontal divergence angle of the laser chip according to the formula (N-1)×2°. The test device does not require an expensive spot tester, nor does it require coupling optical fiber or PD chip, and the test time is short.
[0008] On the basis of the above technical solution, the present invention can also be improved as follows.
[0009] Furthermore, the PD chip is electrically connected to the PCB board by gold wire bonding, and the laser chip is electrically connected to the PCB board by gold wire bonding or probe.
[0010] Furthermore, a ceramic heat sink is fixed on the PCB board, and the laser chip is mounted on the side of the ceramic heat sink so that the ceramic heat sink completes a 90° turn; the laser chip is electrically connected to the ceramic heat sink, and the ceramic heat sink is electrically connected to the PCB board.
[0011] A further beneficial effect of the above method is that the laser chip divergence angle testing device is suitable for testing the vertical divergence angle of the laser chip.
[0012] Furthermore, the laser chip is electrically connected to the ceramic heat sink by gold wire bonding, and the ceramic heat sink is electrically connected to the PCB board by gold wire bonding or probe.
[0013] Furthermore, the center angle formed by all PD chips distributed in a circular array on the PCB board is 46°.
[0014] A further beneficial effect of the above is that since the divergence angle of the laser chip is generally less than 45°, the laser chip divergence angle testing device can meet the divergence angle testing requirements of conventional laser chips.
[0015] Furthermore, the center angle between two adjacent PD chips among all PD chips distributed in a circular array on the PCB board is 2°.
[0016] A further beneficial effect of the above method is that the test accuracy of the laser chip divergence angle test device can reach 2°. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a structural diagram of the laser chip divergence angle test device in the utility model for testing the horizontal divergence angle of the laser chip;
[0018] Figure 2 for Figure 1 A partial enlarged view of
[0019] Figure 3 This is a structural diagram of the laser chip divergence angle test device in the utility model for testing the vertical divergence angle of the laser chip;
[0020] Figure 4 for Figure 3 A partial enlarged view of
[0021] Figure 5 Application of the laser chip divergence angle test device in the utility model Figure 1 ;
[0022] Figure 6 Application of the laser chip divergence angle test device in the utility model Figure 2 .
[0023] In the accompanying drawings, the components represented by the reference numerals are listed as follows:
[0024] 1. PCB board, 2. PD chip, 3. Ceramic heat sink, 4. Laser chip. DETAILED DESCRIPTION
[0025] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0026] Example 1
[0027] like Figure 1 , Figure 2 As shown, a laser chip divergence angle test device comprises: a PCB board 1, a plurality of PD chips 2 are attached to the PCB board 1 in a passive patch manner along a circular array, the center angle formed by all the PD chips 2 distributed in a circular array on the PCB board 1 is determined according to the divergence angle of the laser chip 4 to be tested, the larger the divergence angle of the laser chip 4, the larger the center angle formed by all the PD chips 2 distributed in a circular array on the PCB board 1, and the center angle between two adjacent PD chips 2 is determined according to the measurement accuracy, the higher the accuracy, the smaller the center angle between two adjacent PD chips 2, that is, at this time, the interval between the two adjacent PD chips 2 is reduced, and after the reduction, in order to avoid interference between the two adjacent PD chips 2, the radius of the formed circular array needs to be expanded accordingly; the lower the accuracy, the larger the center angle between the two adjacent PD chips 2; the side of the PD chip 2 close to the center of the circle is the light receiving surface, and the PD chip 2 is electrically connected to the PCB board 1;
[0028] The light bar of the laser chip 4 to be tested is located at the center of the PD chip 2 array, that is, at the intersection of the mark points, and the laser chip 4 is electrically connected to the PCB board 1. At this time, the laser chip divergence angle testing device is suitable for testing the horizontal divergence angle of the laser chip 4. Light up the laser chip 4 and observe which PD chip 2 starts to have no photocurrent (or the photocurrent suddenly drops a lot) for subsequent PD chips 2. The horizontal divergence angle of the laser chip 4 can be calculated according to the formula (N-1)×2°.
[0029] Example 2
[0030] like Figure 1 As shown, this embodiment is a further improvement on the basis of embodiment 1, and the details are as follows:
[0031] The PD chip 2 is electrically connected to the PCB board 1 by gold wire bonding, and the laser chip 4 is electrically connected to the PCB board 1 by gold wire bonding or probe.
[0032] Example 3
[0033] like Figure 3 , Figure 4 As shown, this embodiment is a further improvement on the basis of embodiment 1, and the details are as follows:
[0034] A ceramic heat sink 3 is fixed on the PCB board 1, and the ceramic heat sink 3 is fixed on the PCB board 1 in a patch manner. The laser chip 4 is patched on the side of the ceramic heat sink 3, and the ceramic heat sink 3 completes a 90° turn. The laser chip 4 is electrically connected to the ceramic heat sink 3, and the ceramic heat sink 3 is electrically connected to the PCB board 1. At this time, the laser chip divergence angle testing device is suitable for testing the vertical divergence angle of the laser chip 4, and the laser chip 4 is lit. Observe which PD chip 2 starts to have no photocurrent (or the photocurrent suddenly drops a lot) for subsequent PD chips 2, and the vertical divergence angle of the laser chip 4 can be calculated according to the formula (N-1)×2°.
[0035] Furthermore, the laser chip 4 is electrically connected to the ceramic heat sink 3 by gold wire bonding, and the ceramic heat sink 3 is electrically connected to the PCB board 1 by gold wire bonding or probe.
[0036] Example 4
[0037] like Figure 1 , Figure 3 As shown, this embodiment is a further improvement on the basis of Embodiment 1, 2 or 3, and the details are as follows:
[0038] Since the divergence angle of the laser chip 4 is generally less than 45°, the center angle formed by all the PD chips 2 distributed in a circular array on the PCB board 1 is 46°, that is, the measurable range is within 46°, which can meet the divergence angle test requirements of conventional laser chips 4. If a larger range of divergence angles needs to be tested, the number of PD chips 2 can be increased, and the center angle formed by all the PD chips 2 distributed in a circular array on the PCB board 1 can be expanded.
[0039] In addition, the center angle between two adjacent PD chips 2 among all the PD chips 2 distributed in a circular array on the PCB board 1 is 2°, that is, the test accuracy is 2°, and the number of PD chips 2 is 23. If the test accuracy is to be improved, the center angle between two adjacent PD chips 2 is reduced. After the reduction, in order to avoid interference between two adjacent PD chips 2, the radius of the circular array formed needs to be expanded accordingly. If the test accuracy is to be reduced, the center angle between two adjacent PD chips 2 is expanded. The center angle of 2° and the number of PD chips 2 of 23 in this embodiment are only exemplary descriptions.
[0040] For example Figure 5 As shown, starting from the 13th PD chip 2, the subsequent PD chips 2 have no photocurrent (or the photocurrent suddenly drops a lot). According to the formula (13-1)×2°=24°, it can be calculated that the divergence angle of the laser chip is 24°.
[0041] For example Figure 6As shown, starting from the 7th PD chip 2, the subsequent PD chips 2 have no photocurrent (or the photocurrent suddenly drops a lot). According to the formula (7-1)×2°=12°, it can be calculated that the divergence angle of the laser chip is 12°.
[0042] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.
Claims
1. A laser chip divergence angle testing device, characterized in that: include: A PCB board (1) is provided, wherein a plurality of PD chips (2) are attached to the PCB board (1) in a passive patch manner along a circumferential array, the side surface of the PD chip (2) close to the center of the circle is a light receiving surface, and the PD chip (2) is electrically connected to the PCB board (1); the light strip of the laser chip (4) to be tested is located at the center of the PD chip (2) array and is electrically connected to the PCB board (1).
2. A laser chip divergence angle testing device according to claim 1, characterized in that: The PD chip (2) is electrically connected to the PCB board (1) by gold wire bonding, and the laser chip (4) is electrically connected to the PCB board (1) by gold wire bonding or probe.
3. The laser chip divergence angle testing device according to claim 1, characterized in that: A ceramic heat sink (3) is fixed on the PCB board (1), and the laser chip (4) is mounted on the side of the ceramic heat sink (3) so that the ceramic heat sink (3) completes a 90° turn; the laser chip (4) is electrically connected to the ceramic heat sink (3), and the ceramic heat sink (3) is electrically connected to the PCB board (1).
4. A laser chip divergence angle testing device according to claim 3, characterized in that: The laser chip (4) is electrically connected to the ceramic heat sink (3) by gold wire bonding, and the ceramic heat sink (3) is electrically connected to the PCB board (1) by gold wire bonding or probe.
5. A laser chip divergence angle testing device according to any one of claims 1 to 4, characterized in that: The center angle formed by all the PD chips (2) distributed in a circular array on the PCB board (1) is 46°.
6. The laser chip divergence angle testing device according to claim 5, characterized in that: The center angle between two adjacent PD chips (2) among all the PD chips (2) distributed in a circular array on the PCB board (1) is 2°.