Passively Q-switched transverse-diode-pumped Nd^3+:YLF laser oscillator

Abstract
The design and performance of a diode-pumped Nd3+:YLF laser oscillator is described. A simple transverse-pump geometry in which a lensing duct efficiently couples the two-dimensional diode-pump array radiation to the YLF rod is employed. Using a color-center LiF crystal as a passive Q switch, we have produced burst-mode pulse trains that have a total energy of 115 mJ at a 30-Hz pulse-repetition frequency. The Q-switched pulse-train energy is 71% of the optimized free-lasing pulse energy, which is 163 mJ. Using an unstable cavity with a graded-reflectivity output coupler, we have generated Q-switched pulses that have 12-ns duration and near-diffraction-limited spatial profiles.