A simple highly stable and temporally synchronizable Nd:glass laser oscillator delivering laser pulses of variable pulse duration from sub-nanosecond to few nanoseconds

A simple flash lamp pumped Nd:phosphate glass laser oscillator has been designed and set up delivering laser pulses of variable duration from ∼800 ps to 6 ns. It is based on Q-switching and full-wavelength cavity dumping and provides single laser pulse energy of 5 mJ and 11 mJ corresponding to pulse duration of ∼800 ps and 6 ns respectively at an electrical pump energy of 50 J. While the maximum pulse duration is governed by the cavity round trip time, the lower limit is decided by the switching speed of the high voltage pulse to the Pockels cell of the cavity dumper. Output laser pulses have shown enhanced pulse energy stability by dumping the cavity four round trips after the peak buildup. The laser pulses were synchronized with 250 ps positively chirped laser pulse train derived from an independent commercial cw mode locked Nd:fluorophosphate glass laser oscillator. The temporal jitter between these two pulses was measured to be ∼200 ps, limited by the speed of the electronics used.