Short and ultrashort pulses from fiber-amplified and passively Q-switched microchip lasers

Short and ultrashort laser pulses are of immense interest for commercial applications and fundamental science. This range of pulse durations is typically addressed by mode-locked laser systems, which have the reputation of being fairly complex and expensive. A compact and affordable laser system tailored to provide pulses with variable durations from a few picoseconds to several hundred picoseconds, flexible repetition rates, multi-microjoule energy level and megawatt peak powers hold a great potential. The state-of-the-art microchip lasers based on the combination of neodymium- doped yttrium orthovanadate and semiconductor saturable absorber mirror are simple, compact, and produce the shortest pulses (down to several tens of picoseconds) and the highest repetition rates (kilohertz to megahertz range) attainable from Q-switched laser systems. Reducing the pulse duration of these laser sources below ten picoseconds can be a promising alternative to mode-locked systems and interesting for many applications such as high-precision micromachining. The objectives of this thesis include: realization of compact passively Q-switched microchip lasers using a bonding approach, which provides mechanical stability and a sealed laser cavity; investigation of the laser performance and timing jitter, and implementation of a newly proposed jitter-reduction method, study of a feasible concept for further reduction of pulse durations below ten picoseconds and its experimental realization. In addition to experimental results, this thesis reflects necessary theoretical basics and is supported by more than 160 corresponding references.