High repetition rate, tunable, Q-switched diode pumped Tm:YLF laser

Abstract

The aim of work was to characterize a simple oscillator consisted of Tm:YLF crystal end-pumped by a fiber coupled diode laser and active Q-switch with tunability option. About 7 W with near 35% slope efficiency was demonstrated in a free-running mode. The divergence angle was about 4.3 mrad and estimated parameter M2 < 1.3. Continuous tuning by means of Lyot's filter, consisted of 2 quartz plates in the range of 1879.0-1939.4 nm with less than 1-nm linewidth, was achieved. For the best case (10-ms pump pulse duration, 42-A pump current corresponding to 266 mJ of pump energy), the Q-switched energy was 10.5 mJ with pulse duration of 22 ns corresponding to near 0.5 MW peak power. The 2.5 W of average power with 12.6-kW peak power and 2000-Hz repetition rate was demonstrated for cw pumping regime. © 2009 Versita Warsaw and Springer-Verlag Berlin Heidelberg.