Ultra-narrow linewidth single-frequency fiber laser

Abstract

The invention provides an ultra-narrow linewidth single-frequency fiber laser. The ultra-narrow linewidth single-frequency fiber laser is composed of a symmetric variable ripple period grating directly engraved on a rare earth-doped fiber, a wavelength division multiplexer, pumping laser and a fiber isolator, the symmetric variable ripple period grating engraved on the rare earth-doped fiber is welded with a signal end of the wavelength division multiplexer to form an ultra-narrow linewidth fiber laser resonant cavity, the pumping laser is welded with a pumping end of the wavelength division multiplexer, the input end of the optical fiber isolator is connected with the other signal end of the wavelength division multiplexer, pumping laser pumps an optical fiber laser cavity of the erbium-doped optical fiber engraved with the symmetric variable ripple period grating through the optical fiber wavelength division multiplexer, and ultra-narrow linewidth laser is output to the input end of the optical fiber isolator from the other signal end of the wavelength division multiplexer and is output in a one-way mode through the output end of the optical fiber isolator. The ultra-narrow linewidth fiber laser can effectively suppress or eliminate the influence of environmental changes on laser output parameters. The fiber laser has the advantages of being simple in structure, stable in performance and ultra-narrow in output single-frequency laser linewidth.

Description

technical field [0001] The invention relates to the technical field of fiber lasers, in particular to an ultra-narrow linewidth single-frequency fiber laser. Background technique [0002] At present, the main cavity types used in narrow-linewidth single-frequency fiber lasers are wired cavity and ring cavity. The structure of the linear cavity is simple, the cavity is short and the work is stable, and there is basically no problem of mode hopping; the cavity of the ring cavity is long and the gain is high, and various filter devices can be added in the cavity to obtain narrow line width or wavelength Tuning, but there will be random mode hopping. In order to solve this problem, a saturable absorber or composite ring is generally set in the light wave transmission loop to achieve single-frequency output, but this design increases the complexity of the optical path, which directly leads to the large size of the fiber laser and the impact on the environment (temperature, vibra...

AI Technical Summary

Problems solved by technology

However, due to no substantial progress in ultra-narrow-spectrum fiber grating filters, the linewidth of single-frequency fiber lasers has remained at the kHz level, and there has been no breakthrough for a long time

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