High-energy, high-efficiency harmonic generation from a Cr:LiSrAlF(6) laser system

We have developed a near-diffraction-limited Q-switched Cr:LiSrAlF(6) (Cr:LiSAF) laser system capable of producing 860-nm, 400-mJ pulses at a repetition rate of 2 Hz. Our harmonic-generation experiments with beta-BaB(2)O(4) nonlinear crystals have yielded 200 mJ of energy at 430 nm and 40 mJ at 215 nm. To the best of our knowledge, the 50% second-harmonic conversion efficiency and UV energy demonstrated in this research are the highest yet obtained from a Cr:LiSAF laser.