DESIGN AND PERFORMANCE OF A SINGLY RESONANT PICOSECOND LIB3O5 OPTICAL PARAMETRIC OSCILLATOR SYNCHRONOUSLY PUMPED BY A SELF-MODE-LOCKED TI-SAPPHIRE LASER

The design and the operating characteristics of a high-repetition-rate, singly resonant picosecond optical parametric oscillator based on temperature-tuned LiB3O5 and synchronously pumped by a self-mode-locked Ti:sapphire laser at 81 MHz are described. It is shown that LiB3O5 is an excellent nonlinear material candidate for parametric generation of ultrashort pulses because of its broad tunability, small spatial and temporal walk-off, wide acceptance bandwidths, and low dispersion. With a 30-mm-long LiB3O5 crystal cut for noncritical type-I phase matching, average output powers of as much as 325 mW have been obtained at 1.8 times the 650-mW threshold. We demonstrate continuous tuning from 1.15 to 2.26 mu m with a single crystal, limited by the tunability of the Ti:sapphire pump laser. For 1.8-ps input pump pulses, transform-limited signal pulses with durations of 1-1.2 ps and idler pulses with durations of 2-2.2 ps have been generated over 1,2-2.2 mu m without requiring dispersion compensation. (C) 1995 Optical Society of America