Fiber laser

Abstract

The invention relates to a fiber laser which comprises a pumping source, a resonant cavity, a cladding optical power stripper and an output device which are sequentially connected, the resonant cavity comprises a grating I, a gain fiber and a grating II, one end of the grating I is coupled with an output fiber of the pumping source, and the other end of the grating I is coupled with one end of the gain fiber; the other end of the gain fiber is coupled with one end of the grating II; wherein the grating I is a double-cladding grating, and the pumping source is used for outputting pumping light with a preset numerical aperture; or a mode field adapter is arranged between the pumping source and the resonant cavity and is used for converting the pumping light emitted by the pumping source into the pumping light with a preset numerical aperture, so that the numerical aperture of the pumping light entering the resonant cavity is configured to be less than or equal to half of the numerical aperture of the inner cladding of the grating I. The numerical aperture of the pump light entering the resonant cavity is configured to be smaller than or equal to half of the numerical aperture of the inner cladding of the grating I, so that the conversion efficiency of the optical fiber oscillator is improved.

Description

technical field [0001] The invention relates to the field of laser technology, in particular to a fiber laser. Background technique [0002] Fiber lasers have the advantages of good beam quality, high efficiency, good heat dissipation, compact structure, high reliability, and easy maintenance, and have attracted widespread attention. With the continuous expansion of the fiber laser market, the laser industry chain is becoming more and more mature, and the special processing industry has higher and higher power requirements for lasers. When the output power of a single fiber laser reaches thousands of watts, its thermal effect and nonlinear effect become the limiting factors for continued amplification. Optical fiber cascade pumping technology is an effective method to solve the problem of limited output power of a single optical fiber. Different from the traditional 976nm pumping light injected into the ytterbium-doped fiber to directly generate laser output in the 1μm ban...

AI Technical Summary

Problems solved by technology

[0004] However, the numerical aperture of the pump light injected into the resonator by beam combining is relatively large, and it is difficult to be absorbed in the gain fiber 14, resulting in low conversion efficiency of the fiber oscillator and low output power of the fiber laser.

Although increasing the length of the gain fiber can improve the absorption of pump light to a certain extent, increasing the length of the gain fiber will cause the phenomenon of amplified spontaneous emission (ASE) caused by the reabsorption of the 1000nm~1030nm laser, resulting in damage to the laser

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