Laser

Abstract

The invention provides a laser, and relates to the technical field of lasers, and the laser comprises a pumping assembly, a spatial filter, a low reflection grating, an optical gain fiber, and a high reflection grating. The pumping assembly is used for generating pumping light; the pump light sequentially passes through the low-reflection grating, the optical gain fiber and the high-reflection grating, and the low-reflection grating, the optical gain fiber and the high-reflection grating are used for converting the pump light input from the low-reflection grating into signal light, amplifying the signal light, emitting the signal light from the low-reflection grating, and reflecting and outputting the signal light through the spatial filter.

Description

Technical Field

[0001] The present invention relates to the technical field of lasers, and in particular to a laser. Background Art

[0002] The existing laser includes a pump module, a reverse pump combiner, a low-reflection grating, an optical fiber and a high-reflection grating. Multiple pump modules are connected to the low-reflection grating through a combiner. The pump light emitted by the pump module is combined and enters the low-reflection grating. Then, it passes through the optical fiber and the high-reflection grating and is reflected back to the reverse pump combiner to output signal light.

[0003] In addition, in the existing technology, once the size and numerical aperture of the optical gain fiber are determined, the reverse pumping combiner is limited by the tapering process of the combiner and the principle of brightness conservation, and there is a signal light output channel in the middle of the reverse pumping combiner, which occupies a certain coupling input channel. As a result, the input channel in the reverse pumping combiner cannot meet the requirements of large fiber core diameter and high numerical aperture input of a higher power pump source, and it is impossible to realize reverse pumping with a high-power pump laser. Summary of the Invention

[0004] The object of the present invention is to provide a laser to alleviate the technical problem that the existing laser cannot match a high-power pump source to achieve high-power output.

[0005] The present invention provides a laser comprising: a pump assembly, a spatial filter, a low-reflection grating, an optical gain fiber and a high-reflection grating; The pump component is used to generate pump light; The pump light passes through the low-reflection grating, optical gain fiber and high-reflection grating in sequence. The low-reflection grating, optical gain fiber and high-reflection grating are used to convert the pump light input from the low-reflection grating into signal light and amplify it before emitting from the low-reflection grating and being reflected and output by the spatial filter.

[0006] Furthermore, the low-reflection grating includes a first end and a second end relative to each other, the high-reflection grating includes a third end and a fourth end relative to each other, the second end of the low-reflection grating is connected to one end of the optical gain fiber, and the other end of the optical gain fiber is connected to the third end of the high-reflection grating.

[0007] Furthermore, the spatial filter is arranged between the pump assembly and the low-reflection grating, and is used to transmit the pump light to the first end of the low-reflection grating, and reflect and output the signal light emitted from the first end of the low-reflection grating.

[0008] Furthermore, the pump assembly includes a pump source, and at least one pump source emits light whose wavelength matches the absorption peak of the optical gain fiber.

[0009] Furthermore, the laser further includes a first converging lens, and the pump light emitted from the spatial filter is converged by the first converging lens and then enters the low-reflection grating.

[0010] Furthermore, the laser further includes a second converging lens and an optical fiber output head, and the signal light emitted from the signal light output side of the spatial filter is coupled into the optical fiber output head after passing through the second converging lens.

[0011] Furthermore, the laser also includes a fiber cladding light stripper, and the signal light emitted from the second converging lens is coupled into the fiber output head after passing through the fiber cladding light stripper.

[0012] Furthermore, the laser further comprises an indicator light source, and the indicator light generated by the indicator light source is emitted into the high-reflection grating and then output along the same path as the signal light.

[0013] Furthermore, the laser further includes a second filter, and the indicator light emitted from the indicator light source is filtered by the second filter and then emitted into the high-reflection grating; And / or, the spatial filter includes a first filter.

[0014] Furthermore, the pump assembly includes a plurality of pump sources, and the combined light beams emitted by all the pump sources form the pump light; The pump assembly includes a pump source n1 and a pump source n2; The pump assembly further includes a filter h1; The filter h1 is used to transmit the light emitted by the pump source n1, reflect the light emitted by the pump source n2, and combine the two to form a combined light beam L1, and A1 ≥ A2, A1 is the center wavelength interval of the pump source n1 and the pump source n2, and A2 is the minimum wavelength interval that the filter h1 can distinguish; Alternatively, the pump assembly includes a plurality of pump sources, and the light beams emitted by all the pump sources are combined to form the pump light; The pump assembly includes pump source n1, pump source n2, pump source n3... pump source n m , m is greater than or equal to 3; The pump assembly further includes filter h1, filter h2, filter h m-1 ; The filter h1 is used to transmit the light emitted by the pump source n1, reflect the light emitted by the pump source n2, and combine the two to form a combined light beam L1, and A1 ≥ A2, A1 is the center wavelength interval of the pump source n1 and the pump source n2, and A2 is the minimum wavelength interval that the filter h1 can distinguish; The filter h2 is used to transmit the combined light beam L1 and reflect the light emitted by the pump source n3, so that the two beams are combined to form the combined light beam L2, and A3 ≥ A4, where A3 is the minimum wavelength interval between the center wavelength intervals of the pump sources n1 and n2 corresponding to the combined light beam L1 of the pump source n3, and A4 is the minimum wavelength interval that can be distinguished by the filter h2; And so on, The filter h m-1 For transmitting combined beam L m-2 , and reflects the pump source n m The light emitted, and A n-1 ≥A n , A n-1 is the pump source n m and the combined light L m-2 Corresponding pump source n1, pump source n 2…… Pump source n m-1 The minimum wavelength interval in the center wavelength interval, A n is the filter h m-1 The minimum distinguishable wavelength interval is the minimum wavelength interval that can be used to combine the two to form the pump light.

[0015] The present invention has at least the following advantages or beneficial effects: The present invention provides a laser comprising: a pump assembly, a spatial filter, a low-reflection grating, an optical gain fiber, and a high-reflection grating; the pump assembly is used to generate pump light; the pump light passes through the low-reflection grating, the optical gain fiber, and the high-reflection grating in sequence; the low-reflection grating, the optical gain fiber, and the high-reflection grating are used to convert the pump light input from the low-reflection grating into signal light, amplify the signal light, and then emit the signal light from the low-reflection grating and output it through reflection from the spatial filter.

[0016] First, in this embodiment, the laser uses a spatial filter, rather than a fiber combiner, to achieve the injection of pump light and the output of signal light. Therefore, the power limit of the pump source in the pump assembly is removed, and the power of the pump source can be made higher without being affected by the fiber size. Secondly, reverse pumping is implemented to amplify the signal light using low-reflection gratings, optical gain fibers, and high-reflection gratings. While optimizing power distribution, reducing local power density, reducing the interaction between signal light and pump light, and suppressing nonlinear effects (such as SRS), the threshold of nonlinear effects is significantly increased. Then, through the reasonable layout design of various optical components, not only can the application of reverse pumping technology be realized, but the volume utilization of the system can also be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A schematic diagram of a laser provided in an embodiment of the present invention.

[0019] Icons: 1-pump assembly; 2-spatial filter; 3-low-reflection grating; 4-optical gain fiber; 5-high-reflection grating; 6-first converging lens; 7-second converging lens; 8-fiber output head; 9-fiber cladding light stripper; 10-indicator light source; 11-second filter. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0023] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] In addition, the terms "horizontal" and "vertical" do not mean that the components must be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", not that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0026] like Figure 1 As shown, the laser provided by the present invention includes: a pump component 1, a spatial filter 2, a low-reflection grating 3, an optical gain fiber 4 and a high-reflection grating 5.

[0027] The pump assembly 1 includes a pump source. The number of pump sources can be one or more. In this embodiment, the number of pump sources is three. Light emitted by all the pump sources passes through the spatial filter 2 to form pump light.

[0028] Specifically, the pump assembly 1 may include a pump source n1, a pump source n2, a pump source n3, ... pump source n m , m is greater than or equal to 2; the pump assembly 1 further includes filter h1, filter h2...filter h m-1 The filter h1 is used to transmit the light emitted by the pump source n1, reflect the light emitted by the pump source n2, and combine the two to form a combined light beam L1, and A1 ≥ A2, A1 is the center wavelength interval of the pump source n1 and the pump source n2, and A2 is the minimum wavelength interval that the filter h1 can distinguish; the filter h2 is used to transmit the combined light beam L1 and reflect the light emitted by the pump source n3, so that the two can be combined to form a combined light beam L2, and A3 ≥ A4, A3 is the minimum wavelength interval in the center wavelength intervals of the pump source n1 and the pump source n2 corresponding to the combined light beam L1 of the pump source n3, and A4 is the minimum wavelength interval that the filter h2 can distinguish; and so on. m-1 For transmitting combined beam L m-2 , and reflects the pump source n m The light emitted, and A n-1 ≥A n , A n-1 is the pump source n m and the combined light L m-2 Corresponding pump source n1, pump source n 2…… Pump source nm-1 The minimum wavelength interval in the center wavelength interval, A n is the filter h m-1 The minimum distinguishable wavelength interval is the minimum wavelength interval that can be used to combine the two to form the pump light.

[0029] Among them, A3 is the minimum wavelength interval among the center wavelength intervals of the pump source n3 and the pump source n1 and the pump source n2 corresponding to the combined light L1, including: setting the center wavelength interval between the center wavelength of the light emitted by the pump source n3 and the center wavelength of the light emitted by the pump source n1 corresponding to the combined light L1 to M, and setting the center wavelength interval between the center wavelength of the light emitted by the pump source n3 and the center wavelength of the light emitted by the pump source n2 corresponding to the combined light L1 to N. If M>N, then A3 is the minimum wavelength interval N among the center wavelength intervals of the pump source n3 and the pump source n1 and the pump source n2 corresponding to the combined light L1.

[0030] Among them, A n-1 is the pump source n m and the combined light L m-2 Corresponding pump source n1, pump source n 2…… Pump source n m-1 The minimum wavelength interval in the center wavelength interval includes: obtaining the pump source n m The central wavelength of the combined light L m-2 Each corresponding pump source (including pump source n1, pump source n 2…… Pump source n m-1 ) of the center wavelength, and finally get m-1 center wavelength intervals. Compare the sizes of the m-1 center wavelength intervals and finally determine that the smallest center wavelength interval is A n-1 .

[0031] In this embodiment, m = 3, meaning that pump assembly 1 has three pump sources and two filters. When coupling pump sources of different wavelengths, the pump source wavelength configuration requirements are as follows: Since coupling pump sources of different wavelengths is achieved through filters (e.g., dichroic filters), the center wavelength spacing between the pump sources of different wavelengths must be greater than or equal to the minimum wavelength spacing that the filters can distinguish. For example, for pump sources n1 and n2, A1 ≥ A2, where A1 is the center wavelength spacing between pump sources n1 and n2, and A2 is the minimum wavelength spacing distinguishable by filter h1. Typically, dichroic filters can distinguish wavelengths as small as approximately 30 nm, meaning the center wavelengths of pump sources n1 and n2 must be at least 30 nm apart.

[0032] After being emitted, the pump light enters the low-reflection grating 3, then passes through the optical gain fiber 4 and is emitted to the high-reflection grating 5. Specifically, the low-reflection grating 3 includes a first end and a second end, and the high-reflection grating 5 includes a third end and a fourth end. The second end of the low-reflection grating 3 is connected to one end of the optical gain fiber 4, and the other end of the optical gain fiber 4 is connected to the third end of the high-reflection grating 5. The distribution of the low-reflection grating 3, the optical gain fiber 4, and the high-reflection grating 5 is not limited to the in-line arrangement in this embodiment; other distribution methods can also be used based on the internal space of the laser.

[0033] The low-reflection grating 3 , optical gain fiber 4 and high-reflection grating 5 are used to convert the pump light input from the low-reflection grating 3 into signal light, amplify the signal light, and then emit it from the low-reflection grating 3 and output it through reflection from the spatial filter 2 .

[0034] Using reverse pumping to generate signal light, this structure achieves a more uniform power distribution of pump and signal light within the fiber, avoiding the excessively high signal light power at the fiber end that occurs with forward pumping. This uniform power distribution reduces local power peaks, thereby minimizing the occurrence of nonlinear effects. Reverse pumping allows the signal light power to gradually increase within the fiber, rather than peaking in a single region, thereby lowering the local power density. Furthermore, lower local power density raises the threshold for nonlinear effects. In reverse pumping, the signal and pump light propagate in opposite directions, shortening their interaction time. This design reduces energy exchange and nonlinear interactions between the signal and pump light, thereby suppressing the occurrence of nonlinear effects. Reverse pumping also achieves a more uniform gain distribution within the fiber, avoiding the gain concentration at the fiber end that occurs with forward pumping. This uniform gain distribution helps reduce signal light power fluctuations within the fiber, thereby minimizing the occurrence of nonlinear effects. By reducing the local power density of the signal light, reverse pumping effectively raises the threshold for stimulated Brillouin scattering (SRS), thereby suppressing its occurrence.

[0035] In the existing technology, especially in high-power application scenarios, it is theoretically possible to set up multiple laser chips / lasers, each laser chip / laser and optical fiber to generate multiple light beams, and then combine the multiple light beams based on a beam combiner to achieve reverse pumping and thus achieve the purpose of signal light output; however, the technical problems that cannot be solved include the fact that the optical power is positively correlated with the optical fiber size, and that achieving light output based on a beam combiner will cause very high loss of the actual optical power, and in the existing technology, it is impossible to achieve the input of pump light and the output of signal light through a beam combiner.

[0036] First, in this embodiment, the laser uses a spatial filter 2, rather than a fiber combiner, to achieve pump light injection and signal light output. This eliminates the power limitation of the pump source in the pump assembly 1, allowing for higher pump source power without being affected by fiber size. Furthermore, reverse pumping is achieved using a low-reflection grating 3, optical gain fiber 4, and a high-reflection grating 5 to amplify the signal light. This significantly increases the threshold for nonlinear effects by optimizing power distribution, reducing local power density, minimizing the interaction between signal and pump light, and suppressing nonlinear effects (such as SRS).

[0037] Under the action of the pump source, the ytterbium ions in the optical gain fiber 4 absorb the energy of the pump light and transition from the ground state to the excited state, forming a population inversion distribution. When the signal light passes through the optical gain fiber 4, the excited ytterbium ions transition to the ground state or a lower energy level and emit photons with the same or similar wavelength as the signal light, thereby amplifying the signal light. As the signal light propagates through the optical gain fiber 4, it stimulates the excited ytterbium ions to produce stimulated emission. The emitted photons have the same frequency, phase, and propagation direction as the signal light. These additional photons are superimposed on the original signal light, enhancing the signal light intensity.

[0038] In one embodiment, the optical gain fiber 4 has a high doping concentration, good optical quality, and a suitable core diameter. The high doping concentration includes a high ytterbium ion doping concentration in the optical gain fiber 4 to provide sufficient gain medium. A higher doping concentration increases the number of active ions per unit length of fiber, thereby improving the amplification capability of signal light. However, a higher doping concentration is not necessarily better. Excessively high doping concentrations can lead to enhanced interactions between ions, causing concentration quenching and other issues, thus affecting the performance of the fiber.

[0039] Good optical quality includes low optical loss and high transparency in the optical gain fiber 4 to ensure efficient transmission of pump and signal light within the fiber. Optical loss primarily includes absorption and scattering losses. Low optical loss reduces energy loss during transmission, improving pump efficiency and signal amplification. Furthermore, the fiber's refractive index must be uniform to avoid signal scattering and increased transmission loss caused by uneven refractive index.

[0040] Among them, the appropriate core diameter, including the size of the core diameter of the optical gain fiber 4, will affect the power density of the pump light and the signal light, as well as the degree of overlap between them. For example, the core diameter is 10 μm-100 μm, the cladding is 250-900 μm, and the overlap is 10 μm-100 μm. For reverse pumping, a larger core diameter facilitates the coupling of the pump light and the signal light, reducing coupling losses. At the same time, a larger core can also reduce the impact of nonlinear effects such as self-phase modulation. However, an excessively large core diameter will also increase the mode volume of the optical fiber, reduce the power density per unit area, and be detrimental to the amplification of the signal light. Therefore, it is necessary to select an appropriate core diameter based on the specific application requirements.

[0041] The relationship between the wavelength of the pump light input into optical gain fiber 4 and the output signal light is as follows: The pump light enters optical gain fiber 4 to excite the ytterbium ions in the optical gain fiber 4 to a high energy level, forming a population inversion distribution. This is one of the fundamental conditions for signal light amplification. When the signal light passes through optical gain fiber 4 with a population inversion distribution, it stimulates the high-energy ytterbium ions to emit stimulated radiation, generating photons with the same or similar wavelength as the signal light, thereby amplifying the signal light. Different gain media have specific absorption spectra. The pump wavelength must match the absorption peak of the gain medium to ensure that the pump light is effectively absorbed and converted into laser energy. To achieve effective amplification, the input pump light wavelength must match the absorption peak of the ytterbium ions in the optical gain fiber 4 to ensure sufficient absorption and conversion into excitation energy for the ytterbium ions. For example, the pump wavelength is typically in the range of 880nm-1018nm, which coincides with the absorption peak of Yb³⁺ ions. The choice of pump source also affects the conversion efficiency of pump light to signal light: a suitable pump source wavelength can improve pump efficiency, reduce unnecessary energy loss, and thus enhance the amplification effect of signal light. Typically, the conversion efficiency at a wavelength of 976nm is 75%-85%, 915nm is 65%-75%, and 940nm is between the two.

[0042] The spatial filter 2 can be positioned between the pump assembly 1 and the low-reflection grating 3. The spatial filter 2 can include a first filter configured to transmit the pump light toward the first end of the low-reflection grating 3 and reflect and output the signal light emitted from the first end of the low-reflection grating 3. Both the pump light and the signal light propagate through the same component (i.e., the spatial filter 2), reducing space occupancy and product size.

[0043] A first converging lens 6 can be provided between the spatial filter 2 and the low-reflection grating 3 so that the pump light converges and enters the low-reflection grating 3. By concentrating the pump light into a small area, the first converging lens 6 can significantly increase the energy density of the area, thereby increasing the energy density and improving the imaging quality.

[0044] The signal light output side of the spatial filter 2 can be sequentially provided with a second converging lens 7 and an optical fiber output head 8. Similarly, the second converging lens 7 can concentrate the signal light into a small area, and the second converging lens 7 can significantly increase the energy density of the area, thereby increasing the energy density and improving the imaging quality.

[0045] An optical fiber cladding light stripper 9 may be provided between the second converging lens 7 and the optical fiber output head 8. The optical fiber cladding light stripper 9 strips the cladding light while minimizing the impact on the main signal light.

[0046] The laser also includes an indicator light source 10. In this embodiment, the light output end of the indicator light source 10 is connected to the fourth end of the high-reflection grating 5. The indicator light emitted by the indicator light source 10 has the same output path as the signal light. The indicator light source 10 can be red light, which serves as an indicator. The indicator light is output together with the signal light. Specifically, after entering the high-reflection grating 5, the indicator light passes through the optical gain fiber 4, the low-reflection grating 3, the first converging lens 6, the spatial filter 2, the second converging lens 7, and the fiber cladding light stripper 9, and is coupled into the fiber output head 8, thereby facilitating the user to accurately determine the direction and position of the laser beam.

[0047] It should be understood that the output path of the indicator light may pass through all or part of the first converging lens 6, the spatial filter 2, the second converging lens 7, the fiber cladding light stripper 9, and the fiber output head 8; in actual production applications, it is only necessary to ensure that the optical path of the signal light and the optical path of the indicator light are consistent. Figure 1 As shown by the dotted arrow in .

[0048] Furthermore, a second filter 11 may be provided between the indicator light source 10 and the high-reflection grating 5 to prevent the pump light leaked from the high-reflection grating 5 from affecting the indicator light source 10 .

[0049] In this embodiment, the spatial position of each optical device is not fixed, as long as the optical path requirements are met.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser, characterized in that: include: Pump assembly (1), spatial filter (2), low reflection grating (3), optical gain fiber (4) and high reflection grating (5); The pump component (1) is used to generate pump light; The pump light passes through the low-reflection grating (3), the optical gain fiber (4) and the high-reflection grating (5) in sequence. The low-reflection grating (3), the optical gain fiber (4) and the high-reflection grating (5) are used to convert the pump light input from the low-reflection grating (3) into signal light, amplify the signal light, and then emit the signal light from the low-reflection grating (3) and reflect and output the signal light through the spatial filter (2).

2. The laser according to claim 1, characterized in that The low-reflection grating (3) includes a first end and a second end opposite to each other, and the high-reflection grating (5) includes a third end and a fourth end opposite to each other. The second end of the low-reflection grating (3) is connected to one end of the optical gain fiber (4), and the other end of the optical gain fiber (4) is connected to the third end of the high-reflection grating (5).

3. The laser according to claim 2, characterized in that The spatial filter (2) is arranged between the pump component (1) and the low-reflection grating (3), and is used to transmit the pump light toward the first end of the low-reflection grating (3), and reflect and output the signal light emitted from the first end of the low-reflection grating (3).

4. The laser according to claim 1, characterized in that The pump assembly (1) includes a pump source, and at least one pump source emits light whose wavelength matches the absorption peak of the optical gain optical fiber (4).

5. The laser according to claim 1, characterized in that The laser further comprises a first converging lens (6), and the pump light emitted from the spatial filter (2) is converged by the first converging lens (6) and then enters the low-reflection grating (3).

6. The laser according to claim 1, characterized in that The laser further comprises a second converging lens (7) and an optical fiber output head (8), and the signal light emitted from the signal light output side of the spatial filter (2) passes through the second converging lens (7) and is coupled into the optical fiber output head (8).

7. The laser according to claim 6, characterized in that The laser also includes a fiber cladding light stripper (9), and the signal light emitted from the second converging lens (7) is coupled into the fiber output head (8) after passing through the fiber cladding light stripper (9).

8. The laser according to any one of claims 1 to 7, characterized in that: The laser further comprises an indicator light source (10), and the indicator light generated by the indicator light source (10) is emitted into the high-reflection grating (5) and then output along the same path as the signal light.

9. The laser according to claim 8, characterized in that The laser further comprises a second filter (11), and the indicator light emitted from the indicator light source (10) is filtered by the second filter (11) and then emitted into the high-reflection grating (5); And / or, the spatial filter (2) includes a first filter.

10. The laser according to claim 1, characterized in that The pump assembly (1) comprises a plurality of pump sources, and the light beams emitted by all the pump sources are combined to form the pump light; The pump assembly (1) comprises a pump source n1 and a pump source n2; The pump assembly (1) further includes a filter h1; The filter h1 is used to transmit the light emitted by the pump source n1, reflect the light emitted by the pump source n2, and combine the two to form a combined light beam L1, and A1 ≥ A2, A1 is the center wavelength interval of the pump source n1 and the pump source n2, and A2 is the minimum wavelength interval that the filter h1 can distinguish; or, The pump assembly (1) includes a pump source n1, a pump source n2, a pump source n3, ... a pump source n m , m is greater than or equal to 3; The pump assembly (1) further comprises filter h1, filter h2, filter h m-1 ; The filter h1 is used to transmit the light emitted by the pump source n1, reflect the light emitted by the pump source n2, and combine the two to form a combined light beam L1, and A1 ≥ A2, A1 is the center wavelength interval of the pump source n1 and the pump source n2, and A2 is the minimum wavelength interval that the filter h1 can distinguish; The filter h2 is used to transmit the combined light beam L1 and reflect the light emitted by the pump source n3, so that the two beams are combined to form the combined light beam L2, and A3 ≥ A4, where A3 is the minimum wavelength interval between the center wavelength intervals of the pump sources n1 and n2 corresponding to the combined light beam L1 of the pump source n3, and A4 is the minimum wavelength interval that can be distinguished by the filter h2; And so on, The filter h m-1 For transmitting combined beam L m-2 , and reflects the pump source n m The light emitted, and A n-1 ≥A n , A n-1 is the pump source n m and the combined light L m-2 Corresponding pump source n1, pump source n 2…… Pump source n m-1 The minimum wavelength interval in the center wavelength interval, A n is the filter h m-1 The minimum distinguishable wavelength interval is the minimum wavelength interval that can be used to combine the two to form the pump light.

Images