Diode-laser-pumped continuous-wave optical parametric oscillator with a large mid-infrared tuning range

Abstract We report a singly resonant continuous-wave optical parametric oscillator (SRO), which is pumped by a simple semiconductor laser system and operates in the mid-infrared region (2.9 to 3. 6 μ m ). The pump laser system allows for a simple and cost-efficient SRO design with a small footprint. Tuning of the SROs mid-infrared output wavelength by more than 200 nm is demonstrated by scanning the pump laser wavelength through only 1.25 nm, without any need to adjust the SRO settings. The large tuning range is obtained by choosing a pump wavelength (780 nm) that corresponds to a turning point of the group velocity mismatch between the phase-matched signal and idler waves of the SRO.