Semiconductor laser return light tolerance test device and method

Abstract

A semiconductor laser return light tolerance test device includes the following components: a light source component, an online isolator, a beam combiner, a power meter, and a semiconductor laser LD to be tested; the output fiber of the light source component is fused with the input fiber of the online isolator; the output fiber of the online isolator is fused with the pump fiber of the beam combiner; the signal input fiber of the beam combiner is aligned with the power meter; the pigtail of the LD is fused with the signal input fiber of the beam combiner. The present invention also provides a semiconductor laser return light tolerance test method.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor laser testing, and in particular to a semiconductor laser return light tolerance testing device and method. Background Art

[0002] Laser marking is the most mature and widespread application of pulsed fiber lasers. Laser marking is to focus the collimated laser beam to a micron-level spot size through field lenses of different focal lengths and irradiate it onto the surface of the workpiece, instantly generating huge energy to vaporize the surface of the material to achieve the effect of marking the object. Because it does not use a contact processing method and the laser pulse width is very narrow, the heat-affected zone is very small, and the damage to the surface material of the workpiece is minimal. Compared with the use of traditional CO2 and YAG lasers for marking, the use of pulsed laser output laser marking can complete very fine processing, and its small size, high stability, maintenance-free, long working life, and easy installation make it widely used in electronic products, home decoration, chips, automotive parts and other fields.

[0003] However, when processing highly reflective materials, pulsed lasers have a low resistivity and a smooth surface, which results in a low absorption rate of near-infrared lasers. This causes a large amount of laser light to be reflected, and because most lasers are used perpendicular to the material or at a small angle, the returned laser light re-enters the output head, and even part of the returned light is coupled into the energy transmission fiber and transmitted back along the fiber to the inside of the laser, causing the core components inside the laser to remain at high temperatures, thus causing damage to the device. Among them, the semiconductor laser used as a pump source is more sensitive to the returned laser light, and its internal chip is easily damaged by the returned laser light, causing its output power to drop, which in turn causes the entire laser system to fail to work properly.

[0004] At present, there is no test method and device for pump source tolerance to return light in the industry, which limits the application of pulse lasers in the field of high-reflective material processing to a certain extent. Adding return light tolerance test for pump sources and establishing corresponding screening standards can improve the ability of pulse lasers to resist return light and expand the application field of pulse lasers. Summary of the invention

[0005] In view of this, the present invention provides a semiconductor laser return light tolerance testing device and method.

[0006] A semiconductor laser return light tolerance test device, comprising the following components:

[0007] Light source assembly, online isolator, combiner, power meter, semiconductor laser LD to be tested; splice the output fiber of the light source assembly with the input fiber of the online isolator; splice the output fiber of the online isolator with the pump fiber of the combiner; align the signal input fiber of the combiner with the power meter; splice the pigtail of the LD with the signal input fiber of the combiner.

[0008] In the semiconductor laser return light tolerance testing device of the present invention,

[0009] The light source emitted by the light source assembly has an average output power of 20W, an operating frequency of 30-80KHz, and a central wavelength of 1064nm;

[0010] The central wavelength of the online isolator is 1064nm, the bandwidth isolation is greater than 20dB, the insertion loss is less than 1.5dB, and the average power is 20W;

[0011] The single arm power of the beam combiner is 35W;

[0012] The power measurement range of the power meter is 0-60W, and the wavelength range is 900-1100nm.

[0013] The present invention also provides a semiconductor laser return light tolerance test method, which is implemented by any of the semiconductor laser return light tolerance test devices described above, and comprises the following steps:

[0014] S1. Align the signal input fiber of the combiner with the power meter, connect the light source assembly to an external power supply, set the operating frequency to 30KHz, set the MO current to 2A and start at intervals of 1A to 9A, record the power value of the pulse light source emitted by the light source assembly at different currents as P1, and then turn off the light source assembly;

[0015] S2, the tail fiber of the semiconductor laser LD to be tested is fused with the signal input fiber of the combiner, the signal output fiber of the combiner is aligned with the power meter, the LD working current is set to 2A and the interval is 1A to 7A, the power value of LD under different currents is recorded as P2, and then the external power supply is turned off;

[0016] S3, set the pulse light source frequency of the light source assembly to 30KHz, the current to 2A, turn on the light source, and the optical power entering the LD through the combiner signal input optical fiber is P1;

[0017] S4, set the LD working current to 2A and turn it on, gradually increase the current to 7A, and record the power value P3 output by the combiner at this time;

[0018] S5, turning on the LD and the pulse light source at the same time according to steps S3 and S4 and maintaining them for 2 hours, recording the power value P4 output by the combiner at the end of the time, then turning off the pulse light source and LD in turn, and finally turning off the external power supply;

[0019] S6. Calculate the power instability of LD when working as above.

[0020] S7. Set the pulse light source frequency to 30KHz, gradually increase the light source current, and repeat steps S4-S6 to calculate the power instability of LD when the light source is turned on at different powers. When the measured LD power instability value is less than the preset value, confirm that LD meets the requirements for the use of fiber lasers.

[0021] In the semiconductor laser return light tolerance test method of the present invention, the preset value is 3%.

[0022] Beneficial technical effects: The semiconductor laser return light tolerance test method provided by the present invention can provide a test solution for pump source reliability inspection through a relatively simple and easy-to-operate method. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the optical path of the semiconductor laser return light tolerance testing device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0024] like Figure 1 As shown, in an embodiment of the present invention, the present application discloses a semiconductor laser return light tolerance testing device, which includes the following components:

[0025] Light source assembly 1, online isolator 2, combiner 3, semiconductor laser LD4 to be tested, power meter 5; the output fiber of light source assembly 1 is fused with the input fiber of online isolator 2; the output fiber of online isolator 2 is fused with the pump fiber of combiner 3; the signal input fiber of combiner 3 is aligned with power meter 5, and the pigtail of LD4 is fused with the signal input fiber of combiner 3.

[0026] In the semiconductor laser return light tolerance testing device of the present invention,

[0027] The light source emitted by the light source assembly 1 has an average output power of 20W, an operating frequency of 30-80KHz, and a central wavelength of 1064nm.

[0028] The central wavelength of the online isolator 2 is 1064nm, the bandwidth isolation is greater than 20dB, the insertion loss is less than 1.5dB (an inherent indicator of the isolator), and the average power is 20W; the model of the online isolator 2 can be 10 / 125SCF.

[0029] (1+1) combiner 3’s pump fiber MM-S105 / 125-22A, output fiber LMA-GDF-10 / 130-M, signal input fiber LMA-GDF-10 / 130-M, single-arm power 35W.

[0030] The power measurement range of the power meter 5 is 0-60W, and the wavelength range is 900-1100nm.

[0031] The central wavelength of the semiconductor laser (pump source) LD4 is 915 nm.

[0032] An embodiment of the present invention further provides a semiconductor laser return light tolerance test method, which is implemented by any of the semiconductor laser return light tolerance test devices described above, and includes the following steps:

[0033] S1. Align the signal input fiber of the combiner 3 with the power meter, connect the light source assembly 1 to an external power supply (not shown in the attached figure), set the operating frequency to 30KHz, and set the MO (light source operating current, i.e. simulating return light of different powers) current in sequence from 2A to 9A (i.e. 2A, 3A, ..., 8A, 9A). Record the power value of the pulse light source emitted by the light source assembly 1 at different currents as P1, and then turn off the light source assembly 1. The purpose of this step is to test the return light power of different powers entering the LD, so as to provide data support for the subsequent determination of the return light threshold that the LD can withstand.

[0034] S2. Splice the tail fiber of the semiconductor laser LD4 to be tested with the signal input fiber of the combiner 3. Align the signal output fiber of the combiner 3 with the power meter. Set the working current of LD4 to 2A and start at intervals of 1A to 7A. Record the power value of LD4 under different currents as P2, and then turn off the external power supply. This operation step is to record the output power of LD under different working conditions, so as to provide data for subsequent comparison.

[0035] S3, set the pulse light source frequency of light source assembly 1 to 30KHz, the current to 2A, turn on the light source, and the optical power entering LD4 through the signal input optical fiber of combiner 3 is P1; in order to determine the threshold value that LD can withstand the return light, the light source power is turned on from the minimum.

[0036] S4, set the working current of LD4 to 2A and turn it on, gradually increase the current to 7A, and record the power value P3 output by combiner 3 at this time; first test the return light threshold that LD can withstand under this condition when the LD output power is minimum.

[0037] S5. Turn on LD4 and the pulse light source 1 simultaneously according to steps S3 and S4 and maintain them for 2 hours. When the time expires, record the power value P4 output by the combiner 3. Then turn off the pulse light source 1 and LD4 in turn, and finally turn off the external power supply. Verify the output power stability of LD when it is in working state and is subjected to a certain power of return light at the same time, and record the final power value.

[0038] S6. Calculate the power instability of LD4 according to the above operation. Among them, P3 represents the output power value of the LD to be tested when it just starts to work, and P4 represents the output power of the LD before it is shut down after 2 hours of continuous work.

[0039] S7, set the frequency of pulse light source 1 to 30KHz, gradually increase the current of light source 1, and repeat steps S4-S6 to calculate the power instability of LD4 under different powers of the light source. When the measured power instability value of LD4 is less than the preset value of 3%, it is confirmed that LD4 meets the requirements for the use of fiber lasers. Test the output power stability of the LD to be tested under different return light power conditions. If the power instability is ≥3%, the power value output by the pulse light source at this time is the return light threshold that the LD to be tested can withstand.

[0040] In the semiconductor laser return light tolerance test method of the present invention, the preset value is 3%.

[0041] As described above, the embodiments of the present invention are not limited to specific implementation methods. For ordinary technicians in this field, various other corresponding changes and deformations can be made based on the technical concept of the present invention, and all these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims

1. A semiconductor laser return light tolerance test device, characterized in that: It includes the following components: A light source assembly, an online isolator, a beam combiner, a power meter, and a semiconductor laser LD to be tested; the output optical fiber of the light source assembly is fused with the input optical fiber of the online isolator; the output optical fiber of the online isolator is fused with the pump optical fiber of the beam combiner; the power meter is used to align with the signal input optical fiber or the signal output optical fiber of the beam combiner; the pigtail of the LD is fused with the signal input optical fiber of the beam combiner, the light source emitted by the light source assembly has an average output power of 20W, an operating frequency of 30-80KHz, and a central wavelength of 1064nm; the central wavelength of the online isolator is 1064nm, the bandwidth isolation is greater than 20dB, the insertion loss is less than 1.5dB, and the average power is 20W; the single-arm power of the beam combiner is 35W; the power measurement range of the power meter is 0-60W, and the wavelength range is 900-1100nm.

2. A semiconductor laser return light tolerance test method, characterized in that: The method is implemented by the semiconductor laser return light tolerance testing device as claimed in claim 1, comprising the following steps: S1. Align the signal input fiber of the combiner with the power meter, connect the light source assembly to an external power supply, set the operating frequency to 30KHz, set the light source operating current to 2A to 9A in sequence and turn it on with an interval of 1A each time, record the power value of the pulse light source emitted by the light source assembly at different currents as P1, and then turn off the light source assembly; S2, the tail fiber of the semiconductor laser LD to be tested is fused with the signal input fiber of the combiner, the signal output fiber of the combiner is aligned with the power meter, the LD working current is set to 2A to 7A in sequence and each time is 1A, the power value of LD under different currents is recorded as P2, and then the external power supply is turned off; S3, set the pulse light source frequency of the light source assembly to 30KHz, the current to 2A, turn on the light source, and the optical power entering the LD through the combiner signal input optical fiber is P1; S4, set the LD working current to 2A and turn it on, gradually increase the current to 7A, and record the power value P3 output by the combiner at this time; S5, turning on the LD and the pulse light source at the same time according to steps S3 and S4 and maintaining them for 2 hours, recording the power value P4 output by the combiner at the end of the time, then turning off the pulse light source and LD in turn, and finally turning off the external power supply; S6. Calculate the power instability of LD when working as above. ; S7. Set the pulse light source frequency to 30KHz, gradually increase the light source current, and repeat steps S4-S6 to calculate the power instability of LD when the light source is turned on at different powers. When the measured LD power instability value is less than the preset value, confirm that LD meets the requirements for the use of fiber lasers.

3. The semiconductor laser return light tolerance test method according to claim 2, characterized in that: The preset value is 3%.

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