Short pulse generation in neodymium materials by passive feedback on hybrid Q-switched mode-locking operation

Abstract

Synchronous (or hybrid) pumping of femtosecond lasers requires a source of picosecond pulses with high amplitude stability, in a train of at least 100 pulses. Therefore, continuously mode-locked frequency-doubled YAG lasers or argon lasers have been the most commonly used sources. Q-switched solid state lasers would be preferable, because they provide shorter pulses and higher peak powers, but the train generally consists only in a few pulses of widely varying amplitude. It is shown here that inclusion of a two-photon absorber in a hybridly Q-switched and mode-locked solid state laser results in a the generation of roughly 100 pulses of equal amplitude, bandwidth limited and high energy (as compared to the cw mode-locked laser) pulses.