A ZnGeP₂ Optical Parametric Oscillator with Mid-IR Output Power 3W Pumped by a Tm,Ho:GdVO₄ Laser

We report an efficient mid-infrared optical parametric oscillator (OPO) pumped by a pulsed Tm,Ho-codoped GdVO₄ laser. The 10-W Tm,Ho:GdVO₄ laser pumped by a 801nm diode produces 20ns pulses with a repetition rate of 10kHz at wavelength of 2.048μm. The ZnGeP₂ (ZGP) OPO produces 15-ns pulses in the spectral regions 3.65-3.8μm and 4.45-4.65μm simultaneously. More than 3W of mid-IR output power can be generated with a total OPO slope efficiency greater than 58% corresponding to incident 2μm pump power. The diode laser pump to mid-IR optical conversion efficiency is about 12%.