High-power wavelength tunable fiber laser

Abstract

The utility model provides a high-power wavelength tunable fiber laser, which comprises a tunable wavelength seed source module, a fiber amplification module and an isolation output module, the tunable wavelength seed source module is used for generating signal light with different wavelengths, the fiber amplification module is used for amplifying the signal light, and the isolation output module is used for outputting the amplified signal light; the isolation output module comprises an output isolator; the optical fiber amplification module is sequentially provided with a first optical fiber amplification unit, a second optical fiber amplification unit, a third optical fiber amplification unit and a fourth optical fiber amplification unit along the propagation direction of the signal light; according to the utility model, the tunable wavelength seed source module outputs signal light with different wavelengths, and then the signal light is amplified by the four-stage MOPA amplification system and then is output by the output isolator, so that high-power tunable laser output is realized, the application scene is wide, and the all-fiber scheme is adopted, thereby being convenient, reliable and high in integration level.

Description

Technical Field

[0001] This utility model relates to the field of fiber laser technology, specifically to a high-power wavelength tunable fiber laser. Background Technology

[0002] Most existing high-power lasers are single-wavelength laser systems. While meeting specific requirements, they neglect wavelength tunability, reducing their compatibility with different scenarios. For example, they cannot meet the requirements of transmittance testing for optical devices under high power conditions. On the other hand, existing wavelength-tunable lasers have power ranges below 200mW, which cannot meet the needs of high-power tunable wavelength laser output. Utility Model Content

[0003] The purpose of this invention is to provide a high-power wavelength-tunable fiber laser, solving the problem that existing high-power fiber lasers cannot adjust the wavelength of the output laser.

[0004] To achieve the above objectives, this utility model provides a high-power wavelength-tunable fiber laser, comprising: a tunable wavelength seed source module, a fiber amplification module, and an isolation output module. The tunable wavelength seed source module generates signal light of different wavelengths, the fiber amplification module amplifies the signal light, and the isolation output module outputs the amplified signal light. The isolation output module includes an output isolator. The fiber amplification module is sequentially arranged with a first fiber amplification unit, a second fiber amplification unit, a third fiber amplification unit, and a fourth fiber amplification unit along the propagation direction of the signal light. The first fiber amplification unit includes a first-stage doped fiber, a first combiner, a first-stage pump source, and a first isolator. The first end of the first-stage doped fiber is connected to the tunable wavelength seed source module, and the second end of the first-stage doped fiber is connected to the first end of the first combiner. The second end of the first combiner is connected to the first end of the first-stage pump source and the first end of the first isolator. The second fiber amplification unit includes... The third fiber amplification unit comprises a second-stage doped fiber, a second combiner, a first-stage pump source, and a second isolator. The first end of the second-stage doped fiber is connected to the second end of the first isolator, and the second end of the second-stage doped fiber is connected to the first end of the second combiner. The second end of the second combiner is connected to the first end of the second pump source and the second isolator. The fourth fiber amplification unit comprises a fourth-stage doped fiber, a fourth combiner, and a fourth-stage pump source. The first end of the fourth combiner is connected to the second end of the fourth pump source and the third isolator. The second end of the fourth combiner is connected to the first end of the fourth-stage doped fiber and the first end of the third isolator.

[0005] As can be seen from the above scheme, this invention outputs signal light of different wavelengths through a tunable wavelength seed source module, and then amplifies the signal light through a 4-stage MOPA (Master Oscillator Power-Amplifier) ​​amplification system before outputting it through an output isolator. This invention amplifies the signal light stage by stage through a 4-stage MOPA amplification system. The first fiber amplification unit can amplify the signal light power to 1W, the second fiber amplification unit to 5W, the third fiber amplification unit to 10W, and the fourth fiber amplification unit to 200W, thus achieving high-power signal light output. Simultaneously, by adjusting the wavelength of the signal light through a wavelength selection grating, a high-power output of tunable signal light can be obtained. In the fourth fiber amplification unit, the fourth-stage pump source is placed before the fourth combiner, which can reduce the nonlinearity of the output. This invention achieves high-power laser output with tunable wavelength, has a wide range of applications, and is implemented using an all-fiber solution, making it convenient, reliable, and highly integrated.

[0006] A further proposed solution is to equip the first, second, and third isolators with filters.

[0007] Therefore, the isolators set in each fiber amplification unit can suppress ASE (amplifier spontaneous emission noise) during the amplification process, so that the contrast of the final output laser spectrum meets the requirements, and higher power is output while effectively suppressing ASE.

[0008] A further approach is to include an ASE light source module and a wavelength selective grating, with the ASE light source connected to the wavelength selective grating and the wavelength selective grating connected to the first-stage doped fiber.

[0009] Therefore, it can be seen that the seed source of this utility model is easy to implement.

[0010] A further approach is to use a wavelength selection grating with a tuning bandwidth of 1020nm-1100nm and an adjustment interval of 0.1nm.

[0011] Therefore, it can be seen that this utility model can achieve a wide wavelength tuning range.

[0012] A further proposed solution is that the ASE light source includes a 976nm pump light source, a wavelength division multiplexer, and a single-clad active fiber. The 976nm pump light source is connected to the wavelength division multiplexer, and the wavelength division multiplexer is connected to a wavelength selective grating.

[0013] A further approach is to include a cladding light stripper in the output isolation module, with the second end of the fourth-stage doped fiber connected to the output isolator via the cladding light stripper.

[0014] This demonstrates that the cladding light involved in the laser output can be removed from the fiber, accelerating heat dissipation and ensuring stable high-power output.

[0015] A further proposed approach is to use ytterbium-doped fibers for the first, second, third, and fourth stages of doping. Attached Figure Description

[0016] Figure 1 This is an overall structural block diagram of an embodiment of the present utility model.

[0017] Figure 2 This is the optical path design diagram of the tunable wavelength seed source module in this embodiment of the utility model.

[0018] Figure 3 This is the optical path design diagram of the fiber optic amplification module and the output isolation module in the embodiment of this utility model.

[0019] Figure 4 This is a partial optical path design diagram of the fiber optic amplification module in this embodiment of the present invention.

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0021] See Figure 1 The high-power wavelength tunable fiber laser of this embodiment includes a tunable wavelength seed source module 1, a fiber amplification module 2, and an output isolation module 3. The tunable seed source module 1 is connected to the fiber amplification module 2, and the fiber amplification module 2 is connected to the output isolation module 3.

[0022] The tunable wavelength seed source module 1 is used to generate signal light of different wavelengths, the fiber optic amplification module 2 amplifies the signal light obtained from the tunable wavelength seed source module 1, and the isolation output module is used to output the amplified signal light.

[0023] See Figure 2 The tunable wavelength seed source module includes an ASE (Amplified Spontaneous Emission) light source 11 and a wavelength selection grating 12. The ASE light source 11 is connected to the wavelength selection grating 12, and the wavelength selection grating 12 outputs signal light to the first-stage doped fiber 211.

[0024] In this embodiment, the ASE light source 11 includes a 976nm pump light source 111, a wavelength division multiplexer 112, and a single-clad active optical fiber 113. The 976nm pump light source 111 is connected to the wavelength division multiplexer 112, and the wavelength division multiplexer 112 is connected to a wavelength selective grating 12. The tuning bandwidth of the wavelength selective grating is 1020nm-1100nm, with an adjustment interval of 0.1nm.

[0025] In other embodiments, a monitoring module for monitoring system backlighting is also provided, and the input of wavelength division multiplexer 112, i.e., in Figure 2 In the middle, another optical fiber located on the same side as the 976nm pump light source 111 is connected from the wavelength division multiplexer 112 to the monitoring module, thereby monitoring the reflected light through the monitoring module.

[0026] See Figure 3 The fiber optic amplification module 2 is provided with a first fiber optic amplification unit, a second fiber optic amplification unit, a third fiber optic amplification unit and a fourth fiber optic amplification unit in sequence along the direction of signal light propagation.

[0027] The first fiber optic amplification unit includes a first-stage doped fiber 211, a first combiner 212, a first-stage pump source 213, and a first isolator 214. The first end of the first-stage doped fiber 211 is connected to the wavelength selection fiber 12 of the tunable wavelength seed source module 1. The second end of the first-stage doped fiber 211 is connected to the first end of the first combiner 212. The second end of the first combiner 212 is connected to the first ends of the first-stage pump source 213 and the first isolator 214. After amplification by the first fiber optic amplification unit, the signal light output from the second end of the first isolator 214 reaches 1W.

[0028] The second fiber optic amplification unit includes a second-stage doped fiber 221, a second combiner 222, a first-stage pump source 223, and a second isolator 224. The first end of the second-stage doped fiber 221 is connected to the second end of the first isolator 214, and the second end of the second-stage doped fiber 221 is connected to the first end of the second combiner 222. The second end of the second combiner 222 is connected to the first end of the second-stage pump source 223 and the first end of the second isolator 224. After amplification by the second fiber optic amplification unit, the signal light output from the second end of the second isolator 224 reaches 5W.

[0029] The third fiber optic amplification unit includes a third-stage doped fiber 231, a third combiner 232, a third-stage pump source 233, and a third isolator 234. The first end of the third-stage doped fiber 231 is connected to the second end of the second isolator 224, and the second end of the third-stage doped fiber 231 is connected to the first end of the third combiner 232. The second end of the third combiner 232 is connected to both the third-stage pump source 233 and the first end of the third isolator 234. After amplification by the third fiber optic amplification unit, the signal light output from the second end of the third isolator 234 reaches 10W.

[0030] The fourth fiber amplification unit includes a fourth-stage pump source 241, a fourth combiner 242, and a fourth-stage doped fiber 243. The first end of the fourth combiner 242 is connected to the second end of the fourth-stage pump source 241 and the third isolator 234. The second end of the fourth combiner 242 is connected to the first end of the fourth-stage doped fiber 243, and the second end of the fourth-stage doped fiber 243 is connected to the cladding light stripper 31. After amplification by the fourth fiber amplification unit, the signal light input to the cladding light stripper 31 reaches 200W.

[0031] In this embodiment, the first-stage doped fiber, the second-stage doped fiber, the third-stage doped fiber, and the fourth-stage doped fiber are all ytterbium-doped fibers. It is understood that other rare-earth doped fibers, such as erbium-doped or thulium-doped fibers, can also be used.

[0032] See Figure 3 The isolation output module 3 includes a cladding light stripper 31 and an output isolator 32. The second end of the fourth-stage doped fiber 243 is connected to the output isolator 32 through the cladding light stripper 31.

[0033] The first isolator 214, the second isolator 224, and the third isolator 234 are all equipped with filters to suppress the ASE effect during each amplification stage. See also Figure 4 When amplifying signal light of different wavelengths, the coatings of the first isolator 214, the second isolator 224, and the third isolator 234 need to be changed to match the selected target wavelength. Specifically, this is achieved by switching the filters of the first isolator 214, the second isolator 224, and the third isolator 234, so that the filter only outputs the signal light of the target wavelength, thereby suppressing ASE during the amplification process and ensuring that the output spectral contrast meets the requirements.

[0034] The filters in the first isolator 214, the second isolator 224, and the third isolator 234 can be positioned at the incident end, the exit end, or within the internal optical path. Specifically, the first isolator 214, the second isolator 224, and the third isolator 234 can be wedge-type optical isolators. A wedge-type optical isolator includes a first wedge plate, a rotator, and a second wedge plate arranged sequentially along the optical path. The filter can be positioned at any location along the optical path, for example, in front of the first wedge plate. The first isolator 214, the second isolator 224, and the third isolator 234 can also be displacer-type optical isolators. A displacer-type optical isolator includes a first birefringent crystal, a rotator, a half-wave plate, and a second birefringent crystal arranged sequentially along the optical path. The filter can be positioned at any location along the optical path, for example, after the second birefringent crystal.

[0035] In summary, this invention utilizes an ASE light source combined with a wavelength-selective grating as a tunable seed source, followed by amplification through a four-stage MOPA amplification system. For each amplification stage, an isolator filter is provided for ASE suppression, achieving ASE suppression across the entire 1020nm-1090nm wavelength range. This invention achieves high-power tunable laser output, has wide-ranging applications, and employs an all-fiber optic solution, making it convenient, reliable, and highly integrated.

Claims

1. A high-power wavelength-tunable fiber laser, characterized in that, include: The system includes a tunable wavelength seed source module, an optical fiber amplification module, and an isolated output module. The tunable wavelength seed source module is used to generate signal light of different wavelengths, the optical fiber amplification module is used to amplify the signal light, and the isolated output module is used to output the amplified signal light. The isolated output module includes an output isolator. The fiber optic amplification module is provided with a first fiber optic amplification unit, a second fiber optic amplification unit, a third fiber optic amplification unit, and a fourth fiber optic amplification unit in sequence along the propagation direction of the signal light. The first fiber amplification unit includes a first-stage doped fiber, a first bundler, a first-stage pump source, and a first isolator. The first end of the first-stage doped fiber is connected to the tunable wavelength seed source module, the second end of the first-stage doped fiber is connected to the first end of the first bundler, and the second end of the first bundler is connected to the first end of the first-stage pump source and the first end of the first isolator. The second fiber amplification unit includes a second-stage doped fiber, a second combiner, a first-stage pump source, and a second isolator. The first end of the second-stage doped fiber is connected to the second end of the first isolator, the second end of the second-stage doped fiber is connected to the first end of the second combiner, and the second end of the second combiner is connected to the second-stage pump source and the first end of the second isolator. The third fiber amplification unit includes a third-stage doped fiber, a third bundler, a third-stage pump source, and a third isolator. The first end of the third-stage doped fiber is connected to the second end of the second isolator, the second end of the third-stage doped fiber is connected to the first end of the third bundler, and the second end of the third bundler is connected to the third-stage pump source and the first end of the third isolator. The fourth fiber amplification unit includes a fourth-stage doped fiber, a fourth combiner, and a fourth-stage pump source. The first end of the fourth combiner is connected to the fourth-stage pump source and the second end of the third isolator. The second end of the fourth combiner is connected to the first end of the fourth-stage doped fiber. The second end of the fourth-stage doped fiber is connected to the output isolator.

2. The high-power wavelength-tunable fiber laser as described in claim 1, characterized in that: The first isolator, the second isolator, and the third isolator are all equipped with filters.

3. The high-power wavelength-tunable fiber laser as described in claim 2, characterized in that: The tunable wavelength seed source module includes an ASE light source and a wavelength selective grating. The ASE light source is connected to the wavelength selective grating, and the wavelength selective grating is connected to the first-stage doped fiber.

4. The high-power wavelength-tunable fiber laser as described in claim 3, characterized in that: The wavelength selective grating has a tuning bandwidth of 1020nm-1100nm and an adjustment interval of 0.1nm.

5. The high-power wavelength-tunable fiber laser as described in claim 4, characterized in that: The ASE light source includes a 976nm pump light source, a wavelength division multiplexer, and a single-clad active optical fiber. The 976nm pump light source is connected to the wavelength division multiplexer, and the wavelength division multiplexer is connected to the wavelength selective grating.

6. The high-power wavelength-tunable fiber laser as described in any one of claims 1 to 5, characterized in that: The output isolation module includes a cladding stripper, and the second end of the fourth-stage doped fiber is connected to the output isolator through the cladding stripper.

7. The high-power wavelength-tunable fiber laser as described in claim 6, characterized in that: The first-stage doped fiber, the second-stage doped fiber, the third-stage doped fiber, and the fourth-stage doped fiber are all ytterbium-doped fibers.

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