Stabilization of high-energy femtosecond ytterbium fiber lasers by use of a frequency filter

The performance of a femtosecond Yb fiber laser is investigated in the limit of high pulse energy (>10 nJ) and short pulse duration (<100 fs). By reducing the strength of nonlinear polarization rotation and introducing amplitude modulation through an intracavity frequency filter, pulses with unprecedented peak powers can be generated. The laser emits stable 13 nJ pulses that are dechirped to 55 fs duration and are capable of providing 130 kW peak power. (c) 2007 Optical Society of America.