Fiber laser

Abstract

The utility model discloses an optical fiber laser which comprises a pumping source, an active optical fiber and a laser output head. The pumping source is connected with the laser output head through an active optical fiber and is used for outputting signal laser and auxiliary laser; a signal light resonant cavity formed by a signal light high-reflection grating and a signal light low-reflection grating is formed on the active optical fiber, and a plurality of auxiliary light resonant cavities formed by auxiliary light high-reflection gratings and auxiliary light low-reflection gratings and sequentially connected in series are formed on the active optical fiber between the signal light resonant cavity and the laser output head. The fiber laser has a high stimulated Raman scattering effect threshold value, and is simple in structure and low in production and manufacturing cost.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of laser, especially relates to a fiber laser. BACKGROUND

[0002] High-power ytterbium-doped fiber laser is widely used in industrial and national defense fields with the advantages of high electro-optical efficiency, high beam quality, compact system structure and low maintenance cost. However, with the rapid increase of laser power level, stimulated Raman scattering effect (SRS) can quickly convert signal light power into Stokes light, which not only reduces the spectral purity of laser, but also limits the further amplification of laser power. Stimulated Raman scattering effect (SRS) has become a major constraint factor for the development of laser.

[0003] To improve the output upper limit of high-power fiber laser, researchers have proposed a method of injecting auxiliary laser to improve the stimulated Raman scattering effect threshold of fiber laser. This method can greatly improve the stimulated Raman scattering effect threshold of fiber laser. However, the existing technology for realizing this method is to inject signal laser and auxiliary laser into gain fiber through a beam combiner, which not only has a complex structure, but also has a high production cost. UTILITY MODEL CONTENT

[0004] In view of the above problems, the utility model discloses a kind of fiber lasers to overcome above-mentioned problems or at least partially solve above-mentioned problems.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model discloses a kind of fiber lasers, including pump source, active optical fiber and laser output head;

[0007] The pump source is connected with the laser output head by the active optical fiber, for outputting signal laser and auxiliary laser;Signal light resonant cavity is formed with signal light high reflection grating and signal light low reflection grating on the active optical fiber, and a plurality of auxiliary light resonant cavities are formed with auxiliary light high reflection grating and auxiliary light low reflection grating on the active optical fiber between the signal light resonant cavity and the laser output head, and the auxiliary light resonant cavities are connected in series.

[0008] Further, the signal light high reflection grating, the signal light low reflection grating, the auxiliary light high reflection grating and the auxiliary light low reflection grating are formed on the active optical fiber by femtosecond laser.

[0009] Further, the power of the amplified signal laser is three times the power of the amplified auxiliary laser.

[0010] Further, the number of the pump sources is multiple, and the multiple pump sources are connected with the active optical fiber through a fiber combiner.

[0011] Further, the red laser is further included.

[0012] The red laser is connected with the input end of the fiber combiner.

[0013] Further, the cladding light filter is further included.

[0014] The cladding light filter is arranged between the auxiliary light resonant cavity and the laser output head.

[0015] Further, the outer side of the cladding light filter is provided with a water-cooled pipe for cooling the cladding light filter.

[0016] The advantages and beneficial effects of the utility model are:

[0017] In the optical fiber laser, one signal light resonant cavity and a plurality of auxiliary light resonant cavities connected in series are arranged on the same active optical fiber, so that the signal laser and auxiliary laser output by the pump source are amplified through the amplification stage, thereby improving the threshold of the stimulated Raman scattering effect of the optical fiber laser. BRIEF DESCRIPTION OF DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the utility model. Moreover, the same reference numerals are used throughout the drawings to designate the same parts. In the drawings:

[0019] Figure 1 The structure of the optical fiber laser in one embodiment of the utility model is shown in the figure.

[0020] In the figure: 1, pump source; 2, active optical fiber; 3, laser output head; 4, signal light high reflection grating; 5, signal light low reflection grating; 6, signal light resonant cavity; 7, auxiliary light high reflection grating; 8, auxiliary light low reflection grating; 9, auxiliary light resonant cavity; 10, cladding light filter. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the utility model clearer, the utility model technical scheme will be described clearly and completely in combination with specific embodiments of the utility model and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without making creative efforts belong to the scope of protection of the utility model.

[0022] The technical scheme provided by each embodiment of the utility model will be described in detail in combination with the drawings.

[0023] One embodiment of the utility model provides a kind of fiber laser, as shown in Figure 1 The fiber laser includes pump source 1, active optical fiber 2 and laser output head 3. Among them, the number of pump source can be adjusted according to the demand of output power.

[0024] Specifically, pump source 1 is connected with laser output head 3 through active optical fiber 2, for outputting signal laser and auxiliary laser;Active optical fiber 2 is formed with a signal light resonant cavity 6 composed of signal light high reflection grating 4 and signal light low reflection grating 5, that is, signal light resonant cavity 6 is specifically composed of signal light high reflection grating 4 and signal light low reflection grating 5, and active optical fiber 2 between signal light high reflection grating 4 and signal light low reflection grating 5, signal light resonant cavity 6 is used for power amplification of signal laser output by pump source 1, and there are several auxiliary light resonant cavities 9 composed of auxiliary light high reflection grating 7 and auxiliary light low reflection grating 8 in active optical fiber 2 between signal light resonant cavity 6 and laser output head 3, that is, auxiliary light resonant cavity 9 is specifically composed of auxiliary light high reflection grating 7 and auxiliary light low reflection grating 8, and active optical fiber 2 between auxiliary light high reflection grating 7 and auxiliary light low reflection grating 8, auxiliary light resonant cavity 9 is used for power amplification of auxiliary laser output by pump source 1. Among them, the amplification ratio of auxiliary laser power can be controlled by adjusting the setting number of auxiliary light resonant cavity and the distance between auxiliary light high reflection grating and auxiliary light low reflection grating.

[0025] In summary, in the fiber laser of the embodiment, a signal light resonant cavity and several auxiliary light resonant cavities connected in series are arranged on the same active optical fiber, so that the signal laser and auxiliary laser output by the pump source are amplified by the amplification stage, thereby improving the threshold of stimulated raman scattering effect of the fiber laser.

[0026] In the embodiment, the signal light high reflection grating, the signal light low reflection grating, the auxiliary light high reflection grating and the auxiliary light low reflection grating are formed on the active optical fiber by femtosecond laser, so that the manufacturing process of the fiber laser is simpler and faster, thereby further reducing the production cost of the fiber laser.

[0027] And the power of the signal laser after amplification is three times the power of the auxiliary laser after amplification, which makes the threshold of the stimulated Raman scattering effect of the fiber laser higher.

[0028] In other embodiments, the number of pump sources is multiple, and the multiple pump sources are connected with the active optical fiber through the fiber combiner, so that the output power of the fiber laser is higher.

[0029] And the fiber laser further comprises a red laser.

[0030] The red laser is connected with the input end of the fiber combiner. In this way, the visible red light emitted by the red laser can be used to determine whether the optical path of the fiber laser has a problem.

[0031] In the embodiment, as shown in Figure 1 The fiber laser further comprises a cladding light filter 10.

[0032] The cladding light filter 10 is arranged between the auxiliary optical resonant cavity 9 and the laser output head 3, and is used to strip the cladding light in the optical fiber. The cladding light filter can be formed on the optical fiber, for example, the outer surface of the cladding of the optical fiber is treated to be rough.

[0033] Further, a water-cooled pipe (not shown in the figure) is arranged outside the cladding light filter, which is used to cool the cladding light filter, so that the fiber laser can work stably for a long time.

[0034] The above is only a specific embodiment of the present application, and those skilled in the art can make other improvements or modifications on the basis of the above embodiment under the above teaching of the present application. Those skilled in the art should understand that the above specific description is only for better explanation of the purpose of the present application, and the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A fiber laser, characterized by, The pump source, the active optical fiber and the laser output head are connected through the active optical fiber, and the pump source is used for outputting signal laser and auxiliary laser. The signal light high reflection grating, the signal light low reflection grating, the auxiliary light high reflection grating and the auxiliary light low reflection grating are formed on the active optical fiber by femtosecond laser.

2. The fiber laser of claim 1, wherein, The power of the amplified signal laser is three times the power of the amplified auxiliary laser.

3. The fiber laser of claim 1, wherein, The number of the pump sources is multiple, and the multiple pump sources are connected with the active optical fiber through the fiber combiner.

4. The fiber laser of claim 1, wherein, The red laser is further included.

5. The fiber laser of claim 4, wherein, The red laser is connected with the input end of the fiber combiner. The cladding light filter is further included.

6. The fiber laser of any of claims 1-5, wherein, The cladding light filter is arranged between the auxiliary light resonant cavity and the laser output head. The outer side of the cladding light filter is provided with a water-cooled pipe for cooling the cladding light filter.

7. The fiber laser of claim 6, wherein, ​

Images