New infrared injection-seeded optical parametric oscillator with high energy and narrow bandwidth output

Abstract

We report on a new infrared injection-seeded optical parametric oscillator with narrow bandwidth (Γ≤0.2 cm−1) and high energy (E≥4 mJ/pulse) output between 2.5 and 4 μm which has been developed for cluster spectroscopy in molecular beams. The oscillator contains a LiNbO3 crystal pumped by the 1.064 μm fundamental of a Q-switched Nd:YAG laser. In order to reduce the linewidth and to increase the output energy, it is seeded with narrow bandwidth IR-radiation obtained by difference frequency mixing the output of a tunable dye laser with the second harmonic of the same Nd:YAG laser in a LiIO3 crystal.