Low-pump-threshold continuous-wave singly resonant optical parametric oscillator

We describe a compact all-solid-state continuous-wave singly resonant optical parametric oscillator (SRO) with a minimal pump-power requirement. The SRO is based on periodically poled LiNbO3 as the nonlinear material and is pumped by a 1-W diode-pumped Nd:YVO4 minilaser at 1.064 mu m. By exploiting the intracavity pumping technique in a 50-mm crystal, we have achieved SRO operation threshold at a diode pump power of only 310 mW. At 1 W of input diode power, the SRO delivers 70 mW of output power in the nonresonant idler at 3.66 mu m, at a photon conversion efficiency of 55%. Multiparameter tuning of the SRO yields a signal wavelength range from 1.45 to 1.60 mu m and an idler wavelength range from 3.16 to 4.02 mu m in the mid infrared. The device is characterized by robust turnkey operation and long-term amplitude-stable performance. (C) 1998 Optical Society of America.