FIBER LASERS: VECSEL amplification yields femtosecond high-repetition-rate pulses

摘要

Ytterbium (Yb) -doped fiber amplifiers and fiber lasers that use solid-state lasers or gain-switched laser diodes as seed lasers in a master-oscillator power-amplifier (MOPA) configuration can produce picosecond and femtosecond pulses at high average power for materials-processing applications. However, these lasers often suffer from unwanted nonlinear effects that degrade output-pulse shape and duration and limit maximum output power. An alternative technique demonstrated by researchers at the University of Southampton (Southampton, England) uses a modelocked vertical-external-cavity surface-emitting laser (ML-VECSEL) source to produce near-transform-limited, 110 fs duration pulses with 53 W average power from a 500 fs seed pulse.