A 10 GHz Regeneratively Mode-Locked Fiber Laser With Biased Nonlinear Amplifying Loop Mirror

Regeneratively mode-locked fiber lasers are able to generate tens of gigahertz picosecond optical pulses by the emp-loyment of modulator feedback driven by their own harmonic longitudinal beat note. Improvements in performance, such as pulse shortening (or bandwidth broadening) and noise reduction, are desired for many modern applications. Here, we propose and demonstrate an all-fiber polarization-maintaining regeneratively mode-locked Erbium-doped fiber laser that generates 537 fs optical pulses at 10 GHz with supermode suppression over 80 dB by combining and making full use of a biased nonlinear amplifying loop mirror (NALM) for intracavity pulse compression and supermode suppression. The measured single-sideband phase noise is -135.2 dBc/Hz at 10 kHz offset and the root-mean-square timing jitter is 9.3 fs integrated from 10 kHz to 100 MHz. To obtain significant pulse shaping with the biased NALM, dispersion management is introduced by tailoring the net cavity dispersion in the vicinity of zero dispersion to sustain short and high peak pulses inside the cavity. Numerical simulations are implemented to investigate the detailed laser operation and the dependence of its output characteristics on the laser parameters prior to the experiments.