Abstract

We used a passively mode-locked 750 fs Yb:YAG oscillator [1] as seed laser for a diode-pumped thin disk Yb:YAG regenerative amplifier (Fig. 1). We obtained pulse energies of 180 μJ at repetition rates up to 750 Hz and 120 μJ pulses at 1 kHz repetition rate for a pump power of 8 W. The amplified pulse duration was 2.3 ps (Fig. 3), resulting in a pulse peak power of 78 MW. Gain narrowing in the amplifier material and not intracavity dispersion is responsible for the increased pulse duration during amplification. This approach provides an all-solid- state picosecond laser system with more than 100 μj pulse energy due to the relatively broad gain bandwidth (i.e. 5.3 nm) of YbrYAG at 1030 nm. A compact amplifier setup without stretcher and compressor was possible without any damage.

© 1998 Optical Society of America