Optical parametric generation and amplification in barium borate and lithium triborate crystals

Abstract

A picosecond, widely tunable, optical parametric generator–amplifier system can be constructed with barium borate and lithium triborate crystals pumped by third- or second-harmonic output of an active–passive mode-locked Nd:YAG laser. A tunable output of several hundred mirojoules per pulse with a conversion efficiency as high as 30% has been obtained. The tuning range covers from 0.4 to 2.0 or from 0.6 to 2.5 μm and can be extended by sum- and difference-frequency generation to near 0.2 μm in the UV and to near 8 μm in the IR. The output linewidth can be narrowed to near the transform limit with the help of frequency selection by a grating.