Passively harmonic mode-locked Yb-doped fiber laser for supercontinuum generation

Abstract

We demonstrate an all-normal dispersion passively mode-locked Yb-doped fiber laser for the supercontinuum (SC) generation based on the nonlinear polarization rotation technique. A piece of polarization-maintaining fiber is utilized in the cavity as a spectral filter. By changing the pump power as well as the polarization states, pulses at repetition rates of 22.85, 45.7, 91.40 MHz can be achieved, corresponding to the fundamental and the second- and the fourth-ordered repetition rates, respectively. The output spectrum has a central wavelength of 1040 nm with steep edges, which indicates that it is a dissipative soliton (DS) mode-locking state. By launching the amplified DS pulses into a piece of photonic crystal fiber at a fundamental repetition rate, SC exhibiting a spectral range from 700 to 1700 nm is realized.