J. Hellstrom et al., Efficient nanosecond optical parametric oscillators based on periodically poled KTP emitting in the 1.8-2.5-mu m spectral region, OPTICS LETT, 24(17), 1999, pp. 1233-1235
The use of periodically poled KTiOPO4 as a gain medium in efficient nanosec
ond optical parametric oscillators pumped by a flash-lamp-pumped Q-switched
Nd:YAG laser is demonstrated. Parametric radiation in the 1.8-2.5-mu m spe
ctral region was achieved when the crystal temperature was tuned from 10 to
100 degrees C. A maximum total output energy of 1.8 mJ was obtained at a p
ump level of 3.5 mJ. Stable operation was achieved, with conversion efficie
ncies reaching 50%. No gray hacking or laser damage was observed, even for
pump intensities of 450 MW/cm(2). (C) 1999 Optical Society of America.