All-fiber sub-20 ps ultra low repetition rate high peak power mode-locked fiber laser to generate supercontinuum

We report an ultra-low repetition rate self-started mode-locked fiber laser at 1.55 µm spectral region with a sub-20 ps pulse duration at repetition rate of less than 100 kHz leading to high energy and peak power pulses. A repetition rate of 13.8 kHz with the pulsewidth of 17 ps is then achieved and the issue of multiple pulses is mitigated in the linear cavity structure by proper selection of semiconductor saturable absorber and dispersion management in the cavity. A broad supercontinuum achieved using 7 m SM-ZBLAN fiber while pumping with mode-locked fiber laser with repetition rate, pulsewidth, pulse energy and peak power of 53 kHz, 12.5 ps, 16.6 µJ and 1.3 MW, respectively. (letter)