High Repetition-rate And Narrow Pulse Hybrid Mode-Locked Fiber Laser Based On Nonlinear Amplifying Ring Mirror

Compared with solid-state lasers,fiber lasers have the advantages of compact structure,good heat dissipation,low fabrication cost,and high stability,and can produce ultrashort pulses with high repetition frequency.Active mode-locked fiber lasers are confronted with many problems,such as wide output pulse and poor stability,while passive mode-locked fiber lasers can not achieve a high repetition rate.Therefore,a hybrid mode-locked fiber laser,which combines active mode-locking and passive mode-locking,has become a research hotspot at home and abroad.In order to generate short pulses with high repetition frequency,the stability of active mode-locked fiber lasers and the compression of output pulse width is investigated in this thesis.The main work and achievements are as follows:1.The super-mode-locked noise is the main noise of the active mode-locked fiber laser.Based on the all-polarization preserving self-regenerative mode-locked fiber laser,the paper realizes the suppression of the super-mode-locked noise of the active mode-locked laser without other stable technologies and obtains the stable pulse output with the repetition frequency of 10GHz,and the suppressive ratio of the noise of the laser is higher than 70dB.2.The principle of nonlinear amplifying ring mirror as a saturable absorber is studied and applied to pulse compression of active mode-locked fiber lasers.On this basis,a hybrid mode-locked fiber laser based on a nonlinear amplifying ring mirror is proposed and realized.The pulse output is 10GHz and 1.9ps,and the laser has polarization-maintaining and self-starting functions.