Efficient diode-pumped passively Q-switched Raman laser on barium tungstate crystal

An efficient all-solid-state diode-pumped intracavity Raman laser was constructed. This laser was based on three-mirror linear cavity with triangular Brewster-angle-cut Nd:YAG slab crystal pumped by 300-W quasi-CW diode Q-switched by Cr4+:YAG saturable absorber operated at 1064 nm. BaWO4 (barium tungstate) crystal was used as a Raman converter. After the Raman laser optimisation for the first Stokes (1180 nm) the reproducible conversion efficiency was about 40% with respect to the Q-switched laser operation at the fundamental frequency. The corresponding output energy and pulse duration was 1.46 mJ and 3.5 ns, respectively. The top reached Raman laser output energy was 2.3 mJ with the conversion efficiency of 55%. (C) 2002 Elsevier Science B.V. All rights reserved.