Single-frequency pulse fiber laser based on cascade four-wave mixing pulse width compression

The utility model discloses a single-frequency pulse fiber laser based on cascaded four-wave mixing pulse width compression. The single-frequency pulse fiber laser comprises a semiconductor saturable absorber mirror, a gain fiber, a first fiber grating, a wavelength division multiplexer, a semiconductor laser pumping source, a laser power amplifier, a nonlinear medium and a filtering device, the semiconductor saturable absorber mirror, the gain fiber and the first fiber grating form a resonant cavity of the fiber laser seed source, the semiconductor laser pumping source provides pumping energy for the fiber laser seed source, and signal light output by the resonant cavity is output through the wavelength division multiplexer and amplified by the laser power amplifier. Cascade four-wave mixing is carried out through a nonlinear medium to generate a comb-shaped spectrum, and the comb-shaped spectrum is filtered through a filtering device. The single-frequency pulse fiber laser based on cascade four-wave mixing