Low-threshold operation of an all-solid-state KTP optical parametric oscillator

Abstract

We report on the low-threshold operation of a KTP optical parametric oscillator (OPO) pumped by a diode-pumped, Q-switched Nd:YLF laser. Thresholds below 0.5 mJ have been obtained for pumping at 1.047 μm, with internal conversion efficiencies approaching 50%. A threshold model is presented and compared with previous models. Reasonable agreement is observed between experiment and theory. Examination of the spectral properties of the OPO suggests a method of obtaining consistent single-axial-mode operation without insertion of intracavity elements or use of a seed laser.