OPTICAL PARAMETRIC AMPLIFICATION OF 1-KHZ HIGH-ENERGY PICOSECOND MIDINFRARED PULSES AND APPLICATION TO INFRARED TRANSIENT-GRATING EXPERIMENTS ON DIAMOND

Optical parametric generation of high-repetition-rate high-energy pico second mid-IR pulses is demonstrated by use of a Q-switched mode-locke d cavity-dumped output-coupled Nd-YAG laser as the pump source for a s eeded LiIO3 optical parametric amplifier. By mixing a high-energy cavi ty-dumped pulse that is frequency doubled to lambda = 532 nm with a dy e-laser pulse at lambda = 611 nm, we generated 2-muJ, 50-ps pulses at lambda = 4.1 mum at a repetition rate of 1 kHz. The application of the se ER pulses to nonlinear spectroscopy is demonstrated by measurement of the thermal diffusivity of diamond with IR transient-grating experi ments.