Simple, high-performance type II β-BaB↓(2)o↓(4) optical parametric oscillator

摘要

A visibleear-IR optical parametric oscillator (OPO) based on type II phase matching in βBaB↓(2)o↓(4) (BBO) is described. Pumped at 355 nm, this OPO covers 410-2500 nm completely with a single set of standard Nd:YAG cavity optics. The output efficiency is >25%, the linewidth of the OPO is narrower than 1-2 cm↑(-1) without the use of gratings or etalons, and the signal-beam divergence is <400 μrad. Three type I BBO doubling crystals are used to extend the tuning range from 208 to 415 nm. Doubling efficiencies as high as 40% are easily obtained. The reasons for the high doubling and overall system efficiency are discussed. # 1997 Optical Society of America