A high power photonic crystal fiber laser oscillator based on nonlinear polarization rotation mode-locking

Abstract

A high power femtosecond fiber laser based on a Yb-doped large mode area photonic crystal fiber operating in an all-normal dispersion regime is experimentally demonstrated. A ring laser cavity is used without any elements for dispersion compensation. Stable mode-locking is achieved through nonlinear polarization rotation and the dissipative function of a filter. The laser directly outputs 1.03 ps chirped pulses at a 49.09 MHz repetition rate for an average power of 10 W, corresponding to a pulse energy of 202 nJ. The pulses are compressed to 95.5 fs with a grating pair outside the cavity.