Mode-locked fiber laser and method for generating fractional order soliton light pulse

The invention discloses a mode-locked fiber laser and method for generating fractional order soliton optical pulses, and the method is characterized in that the reflection end of a first wavelength division multiplexer is connected with a first pumping source, and the common end of the first wavelength division multiplexer is sequentially connected with a gain fiber and the input end of an output coupler; a first port of the circulator is connected with a first output end of the output coupler, a second port of the circulator is connected with the saturable absorber, and a third port of the circulator is sequentially connected with input ends of the polarization independent isolator, the polarization controller and the spectrum shaper; and the output end of the spectrum shaper is connected with the transmission end of the first wavelength division multiplexer. According to the invention, the spectrum shaper is added in the laser, and the spectrum shaper is utilized to make the dispersion of the second order a