High-brightness high-power fiber laser

Abstract

A high-brightness and high-power fiber laser adopts an oscillator structure and comprises a pumping module, a high-reflectivity fiber grating, a gain fiber, a low-reflectivity fiber grating and a cladding light filter, the gain fiber is a rare earth ion doped ZBLAN fiber which takes ZBLAN as a matrix material and is of an all-solid-state anti-resonance structure, and the low-reflectivity fiber grating is a rare earth ion doped ZBLAN fiber which is of an all-solid-state anti-resonance structure. The gain optical fiber comprises a fiber core area, a cladding area, an anti-resonance area and a coating layer, the anti-resonance area is composed of at least one capillary tube set, each capillary tube set comprises a plurality of capillary tubes, the capillary tubes in each capillary tube set are annularly arranged on the periphery of the fiber core area with the fiber core area as the center, and the cladding layer is arranged on the cladding layer. The matrix material in each capillary tube and the matrix material in the cladding region are the same and are ZBLAN, and the matrix material ZBLAN in the fiber core region is doped with dysprosium ions. According to the invention, the rare earth doped all-solid-state anti-resonance optical fiber is adopted as the gain optical fiber, so that high-brightness, high-power and high-efficiency output can be realized.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of fiber laser, in particular to a high-brightness and high-power fiber laser. Background Art

[0002] Lasers with emission wavelengths in the range of 380 nm - 780 nm (visible light band) have important application prospects in the fields of medicine, astronomy, Bose-Einstein condensation, scientific research, laser display, underwater communication, etc., and have received extensive attention in recent years. For example, seawater has the lowest transmission loss in the blue-green light band, and blue-green lasers are ideal lasers for underwater communication and detection; yellow lasers with a wavelength of 577 ± 5 nm are ideal lasers for fundus laser photocoagulation; the laser guide star system requires a narrow-linewidth yellow laser with a wavelength of 589.1591 nm, etc.

[0003] Currently, lasers used to generate visible light include dye lasers, lasers based on crystal nonlinear frequency conversion, rare-earth ion-doped solid lasers, rare-earth ion-doped fiber lasers, etc. An important solution for generating visible-light fiber lasers currently is to use rare-earth ion-doped fibers as gain fibers to directly output visible light lasers. This type of directly output fiber laser has characteristics such as high power, high beam quality, high efficiency, high robustness, high heat dissipation performance, and a simple and compact system structure that is easy to integrate, and is the main development direction of visible-light band lasers. Summary of the Invention

[0004] Aiming at the technical problems existing in the prior art, the present invention proposes a high-brightness and high-power fiber laser.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: A high-brightness and high-power fiber laser, adopting an oscillator structure, includes a pump module, a high-reflection fiber grating, a gain fiber, a low-reflection fiber grating, and a cladding light filter. The anti-resonant region is composed of at least one capillary group, each capillary group includes a plurality of capillaries, the capillaries in each capillary group are circularly arranged around the core region with the core region as the center, the matrix material in each capillary is the same as the matrix material in the cladding region and is ZBLAN, and the matrix material ZBLAN in the core region is doped with dysprosium ions. ZBLAN is a matrix material made of ZrF4, BaF2, LaF3, AIF3, and NaF.

[0006] Specifically, the pump module is used to output pump light. The pump module, high-reflection fiber grating, gain fiber, low-reflection fiber grating, and cladding light filter are connected in sequence. A resonant cavity is formed between the high-reflection fiber grating and the low-reflection fiber grating. The pump light is absorbed by the gain fiber. At a certain pump light power, signal light is emitted. The signal light oscillates and amplifies back and forth in the resonant cavity and is output through the low-reflection fiber grating and the cladding light filter. The central wavelength of the pump source of the pump module needs to be within the absorption band of the doped ions.

[0007] Preferably, the fibers used to prepare the high-reflection fiber grating, low-reflection fiber grating, and cladding light filter are the same as the gain fiber.

[0008] Preferably, the center of the reflection band of the high-reflection fiber grating is at the signal light wavelength, the reflection bandwidth is 3 nm, and the reflectivity is 99%. The center of the reflection band of the low-reflection fiber grating is at the signal light wavelength, the reflection bandwidth is 1 nm, and the reflectivity is 4% - 90%.

[0009] Preferably, the anti-resonant region is composed of a capillary group. The capillary group includes multiple capillaries. The capillaries are circular nested tubes. Multiple circular nested tubes surround the periphery of the core region. The circular nested tube includes an outer tube and an inner tube disposed inside the outer tube and tangent to the outer tube. There is a gap between adjacent circular nested tubes and the gaps are equal.

[0010] Preferably, the outer diameter of the outer tube of the circular nested tube in the gain fiber is d1, the inner diameter of the inner tube is d2, and the wall thicknesses of the outer tube and the inner tube are the same and are t , by optimizing d1 and d2, the value of the high-order mode suppression ratio (HOMER) at the signal light wavelength is made greater than 100 to achieve single-mode transmission and improve the output beam quality.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: The high-brightness and high-power fiber laser proposed by the present invention adopts all-fiber laser and uses rare-earth doped all-solid anti-resonant fiber as the gain fiber, which can achieve high-brightness, high-power, and high-efficiency visible light output, and has the advantages of simple and compact structure, good heat dissipation effect, high robustness, and high beam quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0013] Figure 1Schematic diagram of the structure of a high-brightness and high-power fiber laser in an embodiment; Figure 2 Schematic diagram of the structure of the gain fiber used in an embodiment; Figure 3 In an embodiment, d2 / d1 = 0.5, and the confinement loss of the 575 nm fundamental mode (LP 01 ) versus d1 / D; Figure 4 In an embodiment, d1 / D = 0.71, and the confinement losses of the fundamental mode (LP 01 ) and higher-order modes (LP 11 ), as well as the higher-order mode suppression ratio (HOMER) versus d2 / d1; Reference numerals in the figure: 1. Pumping module; 2. High-reflection fiber grating; 3. Gain fiber; 4. Low-reflection fiber grating; 5. Cladding light filter; 10. Core region; 20. Cladding region; 30. Anti-resonant region; 40. Coating layer; 301. Outer tube; 302. Inner tube. Specific implementation manners

[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0015] Refer to Figure 1 , for a high-brightness and high-power fiber laser in an embodiment, which adopts an oscillator structure and includes a pumping module 1, a high-reflection fiber grating 2, a gain fiber 3, a low-reflection fiber grating 4, and a cladding light filter 5. The pumping module 1 is used to output pumping light. The pumping module 1, the high-reflection fiber grating 2, the gain fiber 3, the low-reflection fiber grating 4, and the cladding light filter 5 are connected in sequence. A resonant cavity is formed between the high-reflection fiber grating 2 and the low-reflection fiber grating 4. The pumping light is absorbed by the gain fiber 3. At a certain pumping light power, signal light is emitted. The signal light oscillates and amplifies reciprocally in the resonant cavity and is output through the low-reflection fiber grating 4 and the cladding light filter 5. The central wavelength of the pumping source of the pumping module needs to be within the absorption band of the doped ions.

[0016] The center of the reflection band of the high-reflection fiber grating 2 is at the signal light wavelength, the reflection bandwidth is 3 nm, and the reflectivity is 99%. The center of the reflection band of the low-reflection fiber grating 4 is at the signal light wavelength, the reflection bandwidth is 1 nm, and the reflectivity is 4% - 90%.

[0017] Refer toFigure 2 , which is a schematic structural diagram of a gain fiber adopted in an embodiment. The gain fiber 3 is a rare-earth ion-doped ZBLAN fiber with an all-solid anti-resonant structure using ZBLAN as the matrix material. The gain fiber includes a core region 10, a cladding region 20, an anti-resonant region 30, and a coating layer 40. Only the matrix material in the core region 10 is doped with dysprosium ions. The design of the tube structure in the anti-resonant region 30 is not limited, and those skilled in the art can design a suitable anti-resonant structure according to actual requirements and process difficulties. The anti-resonant region 30 is composed of at least one capillary group. Each capillary group includes a plurality of capillaries. The capillaries in each capillary group are circularly arranged around the core region with the core region as the center. The matrix material in each capillary is the same as that in the cladding region and is ZBLAN. The matrix material ZBLAN in the core region is doped with dysprosium ions. ZBLAN is a matrix material made of ZrF4, BaF2, LaF3, AIF3, and NaF. Its material composition ratio is not limited. Those skilled in the art can select the ratio according to experience or select a suitable ratio based on the prior art, or can also directly select a commercial ZBLAN material. The structures and size parameters of the capillaries in the same capillary group are the same, and the structures and size parameters of the capillaries in different capillary groups can be the same or different. The cross-sectional shape of the capillary is not limited, and a circular shape is usually selected for easy drawing.

[0018] Figure 2 In the shown embodiment, the anti-resonant region 30 is composed of a capillary group. The capillary group includes a plurality of capillaries. The capillaries are circular nested tubes. A plurality of circular nested tubes surround the core region 10. The circular nested tube includes an outer tube 301 and an inner tube 302 disposed inside the outer tube 301 and tangent to the outer tube. There is a gap between adjacent circular nested tubes and the gaps are equal.

[0019] In the gain fiber 3, the outer diameter of the circular nested tube is d1, the inner diameter is d2, and the wall thicknesses of the outer tube 301 and the inner tube 302 are the same and are all t , by optimizing d1 and d2, the value of the high-order mode suppression ratio at the signal light wavelength is greater than 100, realizing single-mode transmission and improving the output beam quality. Specifically, the COMSOL software is used for the optimization design of the gain fiber parameters. The process of optimizing d1 and d2 includes: Fix d2 / d1 as a set value (those skilled in the art can select a suitable empirical value as the set value of d2 / d1 according to experience), optimize d1 / D, where D is known, obtain a curve graph of the fundamental mode confinement loss at the signal light wavelength changing with d1 / D, and take the value of d1 / D corresponding to the minimum fundamental mode confinement loss value at the signal light wavelength as the preferred value of d1 / D, and then determine the preferred value of d1; Fix d1 / D to the obtained preferred value of d1 / D, optimize d2 / d1, obtain the curve graphs of the fundamental mode confinement loss, high-order mode confinement loss, and high-order mode suppression ratio of the signal light wavelength varying with d2 / d1, and select the value of d2 / d1 corresponding to the case where the high-order mode suppression ratio value is greater than 100 and the fundamental mode confinement loss is minimized as the preferred value of d2 / d1, thereby determining the preferred value of d2.

[0020] In a specific embodiment, based on Figure 1 the structure shown, a high-brightness and high-power 575 nm fiber laser is proposed for generating and outputting high-brightness and high-power 575 nm fiber laser. The pump source of the pump module 1 uses a semiconductor laser with a central wavelength located at 450 nm. The structure of the gain fiber used is as shown in Figure 2 and will not be elaborated here. The fibers used to prepare the high-reflection fiber grating 2, low-reflection fiber grating 4, and cladding light filter 5 are the same as the gain fiber 3. The center of the reflection band of the high-reflection fiber grating 2 is at 575 nm, the reflection bandwidth is 3 nm, and the reflectivity is 99%. The center of the reflection band of the low-reflection fiber grating 4 is at 575 nm, the reflection bandwidth is 1 nm, and the reflectivity ranges from 4% to 90%. The outer tube 301 of the circular embedded tube in the gain fiber 3 has a diameter of d1, the inner tube 302 has a diameter of d2, and the wall thicknesses of the outer tube 301 and the inner tube 302 are the same and are both t , and by optimizing d1 and d2, the value of the high-order mode suppression ratio (HOMER) at 575 nm is made greater than 100, realizing single-mode transmission and improving the output beam quality.

[0021] The gain fiber 3 has a core region diameter D = 20 μm; the outer tube 301 of the circular embedded tube has a diameter of d1 and the inner tube 302 has a diameter of d2, and the wall thicknesses of the outer tube 301 and the inner tube 302 are the same and are both t . According to the anti-resonance theory ( n 2 and n 1 are the refractive indices of the anti-resonance region and the core region, m is a positive integer), is the resonance wavelength, and the resonance wavelength cannot be transmitted in the core. For the visible light band, the core region has a diameter D = 20 μm, which belongs to a large mode field and can achieve high-power transmission. Combining the flexibility of controlling the high-order mode suppression ratio (HOMER) of the anti-resonance fiber, a single-mode transmission fiber can be designed, thereby realizing high-brightness transmission. Currently, the maximum core diameter of the commonly used step-index fiber is 16 μm, and the output laser beam quality is very poor, with M 2 ~6.08.

[0022] The optical fiber matrix of the present invention uses a ZBLAN matrix with a relatively small phonon energy because a matrix with a high phonon energy enhances the non-radiative relaxation process during the ion transition process, which is not conducive to laser lasing. In addition, the refractive index of the ZBLAN matrix optical fiber is relatively low, and the dispersion in the visible light band is low. When designing the optical fiber, while taking into account a wide transmission band, the wall thickness is appropriate and it is easy to draw. If the wall thickness is too thick, it will affect the transmission loss of the optical fiber, further affecting the power level of the output laser and the efficiency of the fiber laser.

[0023] Combined with the refractive index of the optical fiber matrix, ZBLAN (ZrF4 - BaF2 - LaF3 - AIF3 - NaF) is used as the matrix material, and the wall thicknesses of the outer tube 301 and the inner tube 302 t The preferred value is 1.5 μm. By optimizing d1 and d2, the value of the high-order mode suppression ratio (HOMER) at 575 nm is greater than 100. When the value of HOMER is greater than 100, it can be considered single-mode transmission, and it has a high beam quality. This embodiment proposes a double-clad all-solid anti-resonant optical fiber suitable for the visible light band with a large mode field and a high suppression ratio to achieve the purpose of high-power and high-brightness laser transmission. The COMSOL software is used for the optimized design of the optical fiber parameters. First, determine the optical fiber matrix material and the shape and structure of the anti-resonant region. Combining with the actual application, determine the core region diameter that meets the high-power visible light transmission (the diameter D of the core region in this embodiment is 20 μm); secondly, since the pump light needs to be accurately located at the resonant wavelength, combining the actual drawing difficulty and the influence of the wall thickness on the optical fiber loss, determine the preferred value of the wall thickness of the outer tube and the inner tube of the anti-resonant region according to the anti-resonant theory t The preferred value (in this embodiment t The preferred value is 1.5 μm) and input this parameter. On this basis, input the signal laser wavelength of 575 nm, and then optimize the outer tube and the inner tube diameters of the circular sleeve, that is, d1 and d2, to make the value of the high-order mode suppression ratio (HOMER) at the signal laser wavelength greater than 100 to support the high-brightness transmission of the 575 nm laser. The COMSOL software is used for the optimized design of the gain optical fiber parameters. The process of optimizing d1 and d2 includes: Fix d2 / d1 = 0.5 and optimize d1 / D, where D is known, D = 20 μm, and obtain the curve of the confinement loss of the fundamental mode (LP 01 ) at 575 nm wavelength changing with d1 / D as shown in Figure 3 Shown, take the value of d1 / D corresponding to the minimum confinement loss value of the fundamental mode (LP 01 ) at 575 nm wavelength as the preferred value of d1 / D (in this embodiment it is 0.71), and then determine the preferred value of d1 (in this embodiment it is 14.2 μm). As seen from Figure 3 In, the value of d1 / D is related to the fundamental mode (LP 01The limiting loss value does not change regularly, and only the optimal value can be obtained through optimized design.

[0024] Fix d1 / D to the obtained optimal value of d1 / D (0.71 in this embodiment), optimize d2 / d1, and obtain the fundamental mode (LP) at a wavelength of 575 nm 01 ), the limiting loss of the higher-order mode (LP 11 ), and the change curves of the limiting loss of the higher-order mode and the higher-order mode suppression ratio (HOMER) with d2 / d1, as Figure 4 shown. Select the value of d2 / d1 corresponding to the smaller limiting loss of the fundamental mode (LP 01 ) and the value of the higher-order mode suppression ratio (HOMER) greater than 100 as the optimal value of d2 / d1 (0.61 in this embodiment), and then determine the optimal value of d2 (8.662 μm in this embodiment).

[0025] Matters not described in this invention are well-known technologies.

[0026] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0027] The above-described embodiments merely represent several implementation manners of this application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application should be subject to the appended claims.

[0028] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. For example, gain fibers with other structural parameters can be designed, doping ions can be changed, and the pump light wavelength can be changed to achieve laser output of other signal wavelengths. Similarly, based on Figure 1 the optical path structure shown, an embodiment provides a high-brightness high-power fiber laser for generating and outputting high-brightness high-power 2 μm and 2.3 μm fiber laser outputs. The pump source of the pump module 1 uses a semiconductor laser with a central wavelength located at 793 nm. The structure of the gain fiber used is as Figure 2As shown, it will not be elaborated here. The matrix material ZBLAN in the core region of the gain fiber 3 is doped with thulium ions. The fibers used to prepare the high-reflection fiber grating 2, the low-reflection fiber grating 4, and the cladding light filter 5 are the same as those of the gain fiber 3. The optimization design methods of the outer tube and the inner tube in the anti-resonant region of the gain fiber 3 are the same as those in the above embodiments and will not be elaborated here.

[0029] Based on Figure 1 As shown in the optical path structure, an embodiment provides a high-brightness and high-power fiber laser for generating and outputting high-brightness and high-power 1.9-μm fiber laser output. The pump source of the pump module 1 uses a laser with a central wavelength of 1064 nm. The structure of the gain fiber used is as Figure 2 As shown, it will not be elaborated here. The matrix material ZBLAN in the core region of the gain fiber 3 is doped with thulium ions. The fibers used to prepare the high-reflection fiber grating 2, the low-reflection fiber grating 4, and the cladding light filter 5 are the same as those of the gain fiber 3. The optimization design methods of the outer tube and the inner tube in the anti-resonant region of the gain fiber 3 are the same as those in the above embodiments and will not be elaborated here.

[0030] Based on Figure 1 As shown in the optical path structure, an embodiment provides a high-brightness and high-power fiber laser for generating and outputting high-brightness and high-power 3.24-μm fiber laser output. The pump source of the pump module 1 uses a laser with a central wavelength of 980 nm. The structure of the gain fiber used is as Figure 2 As shown, it will not be elaborated here. The matrix material ZBLAN in the core region of the gain fiber 3 is doped with dysprosium ions. The fibers used to prepare the high-reflection fiber grating 2, the low-reflection fiber grating 4, and the cladding light filter 5 are the same as those of the gain fiber 3. The optimization design methods of the outer tube and the inner tube in the anti-resonant region of the gain fiber 3 are the same as those in the above embodiments and will not be elaborated here.

[0031] Based on Figure 1 As shown in the optical path structure, an embodiment provides a high-brightness and high-power fiber laser for generating and outputting high-brightness and high-power 2.9-μm fiber laser output. The pump source of the pump module 1 uses a laser with a central wavelength of 1.1 μm or 1.3 μm. The structure of the gain fiber used is as Figure 2 As shown, it will not be elaborated here. The matrix material ZBLAN in the core region of the gain fiber 3 is doped with dysprosium ions. The fibers used to prepare the high-reflection fiber grating 2, the low-reflection fiber grating 4, and the cladding light filter 5 are the same as those of the gain fiber 3. The optimization design methods of the outer tube and the inner tube in the anti-resonant region of the gain fiber 3 are the same as those in the above embodiments and will not be elaborated here.

[0032] Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. High brightness and high power fiber laser, using an oscillator structure, including a pump module, a high reflection fiber Bragg grating, a gain fiber, a low reflection fiber Bragg grating and a cladding light filter, characterized in that: The gain fiber is a rare earth ion-doped ZBLAN fiber with an all-solid-state anti-resonance structure using ZBLAN as a matrix material. The gain fiber includes a core region, a cladding region, an anti-resonance region, and a coating layer. The anti-resonance region is composed of at least one capillary group, each capillary group includes a plurality of capillaries, and the capillaries in each capillary group are arranged in a ring around the core region with the core region as the center. The matrix material in each capillary is the same as the matrix material in the cladding region and is ZBLAN. The matrix material ZBLAN in the core region is doped with dysprosium ions.

2. The high-brightness high-power fiber laser according to claim 1, characterized in that: The pump module is used to output pump light. The pump module, high-reflection fiber Bragg grating, gain fiber, low-reflection fiber Bragg grating and cladding light filter are connected in sequence. The resonant cavity formed between the high-reflection fiber Bragg grating and the low-reflection fiber Bragg grating, the pump light is absorbed by the gain fiber, and under a certain pump light power, the signal light is emitted. The signal light is reciprocated and amplified in the resonant cavity and output through the low-reflection fiber Bragg grating and the cladding light filter.

3. The high-brightness high-power fiber laser according to claim 2, characterized in that: The central wavelength of the pump source of the pump module must be within the absorption band of the doped ions.

4. The high-brightness high-power fiber laser according to claim 1, 2 or 3, characterized in that: The optical fiber used to prepare the high-reflection optical fiber grating, the low-reflection optical fiber grating and the cladding light filter is the same as the gain optical fiber.

5. The high-brightness high-power fiber laser according to claim 2, characterized in that: The reflection band center of the high-reflection fiber Bragg grating is at the signal light wavelength, the reflection bandwidth is 3nm, and the reflectivity is 99%. The reflection band center of the low-reflection fiber Bragg grating is at the signal light wavelength, the reflection bandwidth is 1nm, and the reflectivity is 4%~90%.

6. The high-brightness high-power fiber laser according to claim 1 or 2 or 3 or 5, characterized in that: The anti-resonance region is composed of a capillary group, which includes a plurality of capillaries. The capillaries are circular nested tubes. The plurality of circular nested tubes surround the periphery of the core region. The circular nested tubes include an outer tube and an inner tube arranged inside the outer tube and inscribed with the outer tube. There are intervals between adjacent circular nested tubes and the intervals are equal.

7. The high-brightness high-power fiber laser according to claim 6, characterized in that: The outer diameter of the circular nested tube in the gain optical fiber is d1, the inner diameter is d2, and the wall thickness of the outer tube and the inner tube is the same. t By optimizing d1 and d2, the value of the high-order mode suppression ratio at the signal light wavelength is made greater than 100, single-mode transmission is achieved, and the output beam quality is improved.

8. The high-brightness high-power fiber laser according to claim 6, characterized in that: COMSOL software is used to optimize the gain fiber parameters. The process of optimizing d1 and d2 includes: Fix d2 / d1 as a set value, optimize d1 / D, where D is known, obtain a curve of the signal light wavelength fundamental mode limiting loss versus d1 / D, take the d1 / D value corresponding to the minimum signal light wavelength fundamental mode limiting loss value as the optimal value of d1 / D, and then determine the optimal value of d1; Fix d1 / D as the obtained optimal value of d1 / D, optimize d2 / d1, obtain the curve diagram of the fundamental mode limiting loss, high-order mode limiting loss and high-order mode suppression ratio of the signal light wavelength as a function of d2 / d1, select the d2 / d1 value corresponding to the time when the high-order mode suppression ratio value is greater than 100 and the fundamental mode limiting loss is the smallest as the optimal value of d2 / d1, and then determine the optimal value of d2.

9. The high-brightness high-power fiber laser according to claim 7, characterized in that: The pump module is a semiconductor laser with a pump source center wavelength at 450nm, and the high-brightness and high-power fiber laser is used to generate and output high-brightness and high-power 575nm fiber laser.

10. The high-brightness high-power fiber laser according to claim 8, characterized in that: The wall thickness of the outer tube and the inner tube in the anti-resonance region of the gain optical fiber t is 1.5 μm, and the diameter D of the core region is 20 μm; the preferred values ​​of d1 and d2 are 14.2 μm and 8.662 μm respectively.

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