A fiber laser

Abstract

The utility model provides a kind of fiber laser, it is related to laser technology field.The utility model embodiment provides a kind of fiber laser, including pump source, resonant cavity and first gain optical fiber;The output end of pump source is connected with the input end of resonant cavity, and pump source is used to output pump beam to resonant cavity;The output end of resonant cavity is connected with the first end of first gain optical fiber, and resonant cavity absorbs pump beam to generate laser beam, and laser beam is output to first gain optical fiber;First gain optical fiber absorbs the relaxation oscillation peak of resonant cavity, and output laser beam.The utility model embodiment provides a kind of fiber laser, by first gain optical fiber absorption relaxation oscillation peak of resonant cavity, inhibit the relaxation oscillation effect of fiber laser, eliminate relaxation oscillation peak of resonant cavity in time domain, improve the stability of the output power of laser beam, and the beam quality of laser beam is improved.

Description

Technical Field

[0001] This utility model relates to the field of laser technology, and in particular to a fiber laser. Background Technology

[0002] With a wavelength close to the absorption peak of water, the 1927nm laser can be efficiently absorbed by the surface moisture of the skin, achieving precise exfoliation. In the treatment of photoaging, pigmentation (melasma), acne scars, blemishes, wrinkles, and skin rejuvenation, it can precisely vaporize tissue for epidermal or superficial dermal treatment. In urology, the 1927nm laser is used for minimally invasive surgery on urethral or kidney stones. In otolaryngology, it can precisely cut and stop bleeding, and is suitable for delicate surgeries such as vocal cord polyps and mucosal lesions.

[0003] In the existing technology, the laser output of thulium-doped fiber lasers has relaxation oscillation peaks in the time domain and irregular waveforms. If the rising edge of the pump light is slowed down, relaxation oscillations can be suppressed, but the minimum modulation pulse width is limited. If 793nm or 1.5μm continuous light is used to suppress relaxation oscillations, the output signal will have both DC light and pulsed light, which will affect the output quality. Utility Model Content

[0004] This utility model provides a fiber laser that suppresses the relaxation oscillation effect of the fiber laser by absorbing the relaxation oscillation peak of the resonant cavity through a first gain fiber, thereby eliminating the relaxation oscillation peak of the resonant cavity in the time domain, improving the stability of the output power of the laser beam, and enhancing the beam quality of the laser beam.

[0005] This utility model provides a fiber laser, including a pump source, a resonant cavity, and a first gain fiber;

[0006] The output end of the pump source is connected to the input end of the resonant cavity, and the pump source is used to output a pump beam to the resonant cavity;

[0007] The output end of the resonant cavity is connected to the first end of the first gain fiber. The resonant cavity absorbs the pump beam to generate a laser beam and outputs the laser beam to the first gain fiber.

[0008] The first gain fiber absorbs the relaxation oscillation peak of the resonant cavity and outputs a laser beam.

[0009] Optionally, the first gain fiber is a thulium-doped single-mode fiber.

[0010] Optionally, it also includes a pump combiner, and the resonant cavity includes a first reflective grating, a second gain fiber, and a second reflective grating;

[0011] The output end of the pump source is connected to the input end of the pump combiner, the output end of the pump combiner is connected to the first end of the first reflection grating, the second end of the first reflection grating is connected to the first end of the second gain fiber, and the first reflection grating reflects the laser beam and transmits the pump beam.

[0012] The second end of the second gain fiber is connected to the first end of the second reflection grating. The second gain fiber absorbs the pump beam and generates a laser beam.

[0013] The second end of the second reflection grating is connected to the first end of the first gain fiber. The second reflection grating partially reflects the laser beam and partially transmits the laser beam.

[0014] Optionally, the reflectivity of the first reflective grating to the laser beam is greater than that of the second reflective grating to the laser beam.

[0015] Optionally, the first reflective grating has a reflectivity of more than 90% for the laser beam.

[0016] Optionally, the resonant cavity may also include a pump light stripper;

[0017] The input end of the pump light stripper is connected to the second end of the second gain fiber, and the output end of the pump light stripper is connected to the first end of the second fiber grating.

[0018] Optionally, the fiber laser may also include an isolator;

[0019] The input of the isolator is connected to the output of the first gain fiber.

[0020] Optionally, the fiber laser also includes a visible light source and a first beam combiner;

[0021] The output of the visible light source is connected to the first input of the first beam combiner;

[0022] The second input end of the first beam combiner is connected to the output end of the first gain fiber. The first beam combiner combines the visible light output from the visible light source with the laser beam, so that the visible light indicates the optical path position of the laser beam.

[0023] Optionally, the fiber laser also includes a laser output head;

[0024] The input end of the laser output head is connected to the output end of the first gain fiber, and the laser output head outputs a laser beam.

[0025] Optionally, the fiber laser also includes a temperature controller;

[0026] The temperature controller is fixedly connected to the pump source and is used to control the temperature of the pump source within a preset temperature range.

[0027] The fiber laser provided in this embodiment utilizes the reabsorption effect of the first gain fiber to absorb the relaxation oscillation peak of the resonant cavity, thereby suppressing the relaxation oscillation effect of the fiber laser, eliminating the relaxation oscillation peak of the resonant cavity in the time domain, improving the stability of the output power of the laser beam, and enhancing the beam quality of the laser beam.

[0028] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a fiber laser provided in an embodiment of the present invention;

[0031] Figure 2 This is a waveform diagram of a laser beam that does not utilize the first gain fiber to suppress relaxation oscillation peaks.

[0032] Figure 3 This is a waveform diagram of a laser beam that uses the first gain fiber to suppress the relaxation oscillation peak.

[0033] Figure 4 This is the output spectrum of the fiber laser provided in this embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of another fiber laser provided in this embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of another fiber laser provided in this embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram of the structure of another fiber laser provided in this embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram of the structure of another fiber laser provided in this embodiment of the present invention;

[0038] Figure 9 This is a schematic diagram of the structure of another fiber laser provided in this embodiment of the present invention;

[0039] Figure 10 This is a schematic diagram of another fiber laser provided in this embodiment of the present invention. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] This utility model provides a fiber laser. Figure 1 This is a schematic diagram of the structure of a fiber laser provided in an embodiment of this utility model, for reference. Figure 1 The fiber laser includes a pump source 100, a resonant cavity 200, and a first gain fiber 300. The output end of the pump source 100 is connected to the input end of the resonant cavity 200, and the pump source 100 is used to output a pump beam to the resonant cavity 200. The output end of the resonant cavity 200 is connected to the first end of the first gain fiber 300. The resonant cavity 200 absorbs the pump beam to generate a laser beam and outputs the laser beam to the first gain fiber 300. The first gain fiber 300 absorbs the relaxation oscillation peak of the resonant cavity 200 and outputs the laser beam.

[0043] refer to Figure 1Pump source 100 emits a pump beam. Exemplarily, in this embodiment, the wavelength of the pump beam is 793 nm, and the power of the pump beam is 100 W. Resonant cavity 200 absorbs the pump beam and generates a laser beam. The laser beam that meets the resonance condition of the resonant cavity will resonate and amplify within the resonant cavity and be output from resonant cavity 200 to the first gain fiber 300. During the output of the laser beam from resonant cavity 200, the number of inverted particles in the gain medium of resonant cavity 200 continuously decreases. Since the energy of the pump light absorbed by resonant cavity 200 is insufficient to replenish the consumed number of inverted particles, this causes oscillations in the power of the laser beam output from resonant cavity 200, affecting the beam quality of the laser beam. Figure 2 This is a waveform diagram of a laser beam that does not utilize the first-gain fiber to suppress relaxation oscillation peaks. Figure 3 This is a waveform diagram of a laser beam with relaxation oscillation peaks suppressed using the first gain fiber, for reference. Figure 2 and Figure 3 , Figure 2 and Figure 3 The horizontal axis represents time, and the vertical axis represents output power. Figure 2 The waveform outlined in the red dashed box represents the relaxation oscillation peak. Utilizing the reabsorption effect of the first gain fiber 300, the relaxation oscillation peak of the resonant cavity 200 can be absorbed, thus outputting a waveform similar to... Figure 3 The square wave pulse shown improves the stability of the laser beam's output power. Optionally, the fiber laser can output a 1927nm laser beam. Figure 4 This is the output spectrum of the fiber laser provided in this embodiment of the present invention, for reference. Figure 4 The x-axis represents the wavelength of the laser beam, and the y-axis represents the beam intensity. For example, in one embodiment, the pump beam power is 62W, the laser beam output power is 25W, the optical efficiency of the fiber laser is greater than 40%, and the fiber laser can output both continuous laser beams and laser beams with pulse widths between 10μs and 1s and pulse frequencies between 1Hz and 20000Hz.

[0044] The fiber laser provided in this embodiment utilizes the reabsorption effect of the first gain fiber to absorb the relaxation oscillation peak of the resonant cavity, thereby suppressing the relaxation oscillation effect of the fiber laser, eliminating the relaxation oscillation peak of the resonant cavity in the time domain, improving the stability of the output power of the laser beam, and enhancing the beam quality of the laser beam.

[0045] Optionally, the first gain fiber is a thulium-doped single-mode fiber. Thulium-doped fibers have a wider gain bandwidth, enabling flexible wavelength tuning and improving the output flexibility of fiber lasers. Furthermore, the structured beam output from thulium-doped single-mode fibers exhibits good monochromaticity, strong directionality, and high stability, making them suitable for precision machining and medical applications.

[0046] Figure 5 This is a schematic diagram of another fiber laser provided in an embodiment of the present invention, for reference. Figure 5 The fiber laser also includes a pump combiner 400, and a resonant cavity 200 including a first reflection grating 201, a second gain fiber 202, and a second reflection grating 203. The output end of the pump source 100 is connected to the input end of the pump combiner 400, the output end of the pump combiner 400 is connected to the first end of the first reflection grating 201, and the second end of the first reflection grating 201 is connected to the first end of the second gain fiber 202. The first reflection grating 201 reflects the laser beam and transmits the pump beam. The second end of the second gain fiber 202 is connected to the first end of the second reflection grating 203. The second gain fiber 202 absorbs the pump beam and generates a laser beam. The second end of the second reflection grating 203 is connected to the first end of the first gain fiber 300. The second reflection grating 203 partially reflects the laser beam and partially transmits the laser beam.

[0047] refer to Figure 5 A pump combiner 400 is used to combine the pump beams. Optionally, the pump source 100 may include multiple light-emitting units, and the pump combiner 400 can combine the pump beams emitted by each light-emitting unit and output them to the resonant cavity 200. The first reflection grating 201 can transmit the pump beam, allowing the pump beam to reach the second gain fiber 202. The second gain fiber 202 absorbs the pump beam and generates a laser beam. At the same time, the first reflection grating 201 and the second reflection grating 203 can reflect the laser beam generated by the second gain fiber 202, so that the laser beam that meets the resonance condition of the resonant cavity 200 oscillates in the resonant cavity 200, while the laser beam that does not meet the resonance condition of the resonant cavity 200 cannot oscillate in the resonant cavity 200. Meanwhile, a portion of the laser beam incident on the second reflection grating 203 will be transmitted through the second reflection grating 203, and this portion of the laser beam will be incident on the first gain fiber 300. The first gain fiber 300 will eliminate the relaxation oscillation peak of the laser beam and output this portion of the laser beam. For example, the length of the first gain fiber 300 in the fiber laser is 2m, and the length of the second gain fiber 202 is 2.7m.

[0048] refer to Figure 5 The first reflective grating 201 has a higher reflectivity to the laser beam than the second reflective grating 203. The second reflective grating 203 needs to output a portion of the laser beam while reflecting it, while the first reflective grating 201 needs to reflect as much of the laser beam as possible to reduce damage and improve the quality factor of the resonant cavity 200. Optionally, the first reflective grating 201 has a reflectivity greater than 90%; for example, the first reflective grating 201 has a reflectivity of 99.9% and a bandwidth of 4 nm, while the second reflective grating 203 has a reflectivity of 20% and a bandwidth of 2 nm.

[0049] Figure 6 This is a schematic diagram of another fiber laser provided in this embodiment of the present invention, for reference. Figure 6 The resonant cavity 200 also includes a pump light stripper 204; the input end of the pump light stripper 204 is connected to the second end of the second gain fiber 202, and the output end of the pump light stripper 204 is connected to the first end of the second fiber grating 203.

[0050] refer to Figure 6 Since the absorption rate of the pump beam by the second gain fiber 202 is less than 100%, part of the pump beam will be transmitted through the second gain fiber 202 to the pump beam stripper 204. The pump beam stripper 204 is used to filter out the pump beam in the laser beam, thereby avoiding the pump beam remaining in the laser beam output by the resonant cavity 200, and improving the monochromaticity and beam quality of the laser beam.

[0051] Figure 7 This is a schematic diagram of another fiber laser provided in this embodiment of the present invention, for reference. Figure 7 The fiber laser also includes an isolator 500; the input of the isolator 500 is connected to the output of the first gain fiber 300. The isolator 500 allows only unidirectional light beam passage; a beam propagating from the first gain fiber 300 to the isolator 500 can pass through the isolator 500, while a beam propagating from the isolator 500 to the first gain fiber 300 cannot pass through it. The isolator 500 prevents the beam from returning to the first gain fiber 300 and the resonant cavity 200, ensuring that the first gain fiber 300 and the resonant cavity 200 are not interfered with by external light beams.

[0052] Figure 8 This is a schematic diagram of another fiber laser provided in this embodiment of the present invention, for reference. Figure 8 The fiber laser also includes a visible light source 600 and a first beam combiner 700; the output end of the visible light source 600 is connected to the first input end of the first beam combiner 700; the second input end of the first beam combiner 700 is connected to the output end of the first gain fiber 300, and the first beam combiner 700 combines the visible light output from the visible light source 600 with the laser beam, so that the visible light indicates the optical path position of the laser beam.

[0053] refer to Figure 8 A visible light source 600 is used to emit a visible beam, and a first beam combiner 700 combines the visible beam with the laser beam. Thus, when the fiber laser outputs a laser beam outside the visible light band, the visible beam can indicate the optical path and spot position of the laser beam, allowing the user of the fiber laser to more easily adjust the optical path. Optionally, the wavelength of the visible beam can be 650 nm.

[0054] Figure 9 This is a schematic diagram of another fiber laser provided in this embodiment of the present invention, for reference. Figure 9 The fiber laser also includes a laser output head 800; the input end of the laser output head 800 is connected to the output end of the first gain fiber 300, and the laser output head 800 outputs a laser beam. The laser output head 800 can collimate and converge the laser beam, improve the power density of the laser beam, and improve the stability of the laser beam transmission.

[0055] Figure 10 This is a schematic diagram of another fiber laser provided in this embodiment of the present invention, for reference. Figure 10 The fiber laser also includes a temperature controller 900; the temperature controller 900 is fixedly connected to the pump source 100 and is used to control the temperature of the pump source 100 within a preset temperature range. The temperature of the pump source 100 affects the power and frequency of the pump beam, which in turn affects the efficiency of the fiber laser. By controlling the temperature of the pump source 100 within the preset temperature range, the temperature controller 900 ensures that the instability of the pump beam output by the pump source 100 is less than or equal to 0.9%, thereby maintaining the stable operation of the fiber laser. The temperature controller 900 may include an air-cooled module or a water-cooled module.

[0056] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A fiber laser, characterized in that, Includes a pump source, a resonant cavity, and a first gain fiber; The output end of the pump source is connected to the input end of the resonant cavity, and the pump source is used to output a pump beam to the resonant cavity; The output end of the resonant cavity is connected to the first end of the first gain fiber. The resonant cavity absorbs the pump beam to generate a laser beam and outputs the laser beam to the first gain fiber. The first gain fiber absorbs the relaxation oscillation peak of the resonant cavity and outputs the laser beam; The first gain fiber is a thulium-doped single-mode fiber with a length of 2m.

2. The fiber laser according to claim 1, characterized in that, It also includes a pump combiner, and the resonant cavity includes a first reflective grating, a second gain fiber, and a second reflective grating; The output end of the pump source is connected to the input end of the pump combiner, the output end of the pump combiner is connected to the first end of the first reflection grating, the second end of the first reflection grating is connected to the first end of the second gain fiber, and the first reflection grating reflects the laser beam and transmits the pump beam. The second end of the second gain fiber is connected to the first end of the second reflection grating. The second gain fiber absorbs the pump beam and generates the laser beam. The second end of the second reflective grating is connected to the first end of the first gain fiber. The second reflective grating partially reflects the laser beam and partially transmits the laser beam.

3. The fiber laser according to claim 2, characterized in that, The reflectivity of the first reflective grating to the laser beam is greater than that of the second reflective grating to the laser beam.

4. The fiber laser according to claim 2, characterized in that, The first reflective grating has a reflectivity of more than 90% for the laser beam.

5. The fiber laser according to claim 2, characterized in that, The resonant cavity also includes a pump optical stripper; The input end of the pump light stripper is connected to the second end of the second gain fiber, and the output end of the pump light stripper is connected to the first end of the second reflection grating.

6. The fiber laser according to claim 1, characterized in that, The fiber laser also includes an isolator; The input end of the isolator is connected to the output end of the first gain fiber.

7. The fiber laser according to claim 1, characterized in that, The fiber laser also includes a visible light source and a first beam combiner; The output end of the visible light source is connected to the first input end of the first beam combiner; The second input end of the first beam combiner is connected to the output end of the first gain fiber. The first beam combiner combines the visible light output from the visible light source with the laser beam, so that the visible light indicates the optical path position of the laser beam.

8. The fiber laser according to claim 1, characterized in that, The fiber laser also includes a laser output head; The input end of the laser output head is connected to the output end of the first gain fiber, and the laser output head outputs the laser beam.

9. The fiber laser according to claim 1, characterized in that, The fiber laser also includes a temperature controller; The temperature controller is fixedly connected to the pump source, and the temperature controller is used to control the temperature of the pump source within a preset temperature range.

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