Stimulated Brillouin Scattering Suppression Method for Fiber Laser Amplifier System

Abstract

The invention provides a suppression method for stimulated Brillouin scattering of an optical fiber laser amplifier system. The optical fiber laser amplifier system includes a seed source and an optical fiber amplifier; and inclined optical fiber grating is accessed into the optical fiber amplifier, and filtering is performed on a laser input in the inclined optical fiber grating by utilizing thehigh loss of the inclined optical fiber grating in a Brillouin wave band to suppress the stimulated Brillouin scattering. The inclined optical fiber grating has the high loss in Brillouin wave band and has better suppression effects on backward Stokes signal light generated by the optical fiber laser amplifier system, and so, an overall SBS threshold of the optical fiber laser amplifier system canbe improved, the risk of high power backward light on the optical fiber laser amplifier system is greatly reduced, and the performance of the optical fiber laser amplifier system is improved.

Description

technical field [0001] The invention belongs to the technical field of fiber lasers, in particular to a method for suppressing stimulated Brillouin scattering of a fiber laser amplifier system. Background technique [0002] Fiber laser amplifiers have the advantages of high efficiency, good beam quality, small size, maintenance-free, low operating cost, high beam quality, long operating life, easy modulation, compact structure, etc., and are widely used in military, industrial and other fields. In special applications such as gravitational wave detection, nonlinear frequency conversion, and beam synthesis, there are special requirements for the power, linewidth, and polarization state of fiber lasers. High-power narrow-linewidth fiber laser amplifiers are effective light sources for these special applications. [0003] For high-power narrow-linewidth fiber laser amplifiers, due to the long length of the fiber and the small cross-sectional area of ​​the fiber core, various n...

AI Technical Summary

Problems solved by technology

Among them, the first two are limited by the manufacturing process of the fiber, and the large mode field area of ​​the fiber will make the threshold of the mode instability (MI) effect lower, which is not conducive to the stability and power improvement of the fiber laser amplifier, and the application is still very limited.

The method of suppressing the Stimulated Brillouin Scattering (SBS) effect by broadening the linewidth of the seed laser through active phase modulation requires the introduction of additional electrical modulation devices, and subsequent linewidth suppression is required, and the system is very complicated.

The method of broadening the Brillouin gain spectrum by applying temperature and stress gradients to suppress the stimulated Brillouin scattering (SBS) effect is difficult to control, and it is easily affected by external factors, and the system is relatively complex.

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