High-power, continuous-wave, singly-resonant, intracavity optical parametric oscillator

A high-power continuous-wave optical parametric oscillator based on the nonlinear material KTiOAsO₄ and pumped internal to a tunable Ti:sapphire laser is described. The use of the intracavity pumping approach has enabled operation of a singly resonant oscillator (SRO), resulting in the generation of as much as 1.46 W of infrared power in a 11.5-mm-long crystal. Amplitude-stable signal and idler outputs, each in excess of 500 mW, over the respective wavelength ranges of 1.11–1.20 and 2.44–2.86 mm have been extracted from the SRO. We demonstrate up to 90% down-conversion of the optimum Ti:sapphire output power to the SRO, confirming our recent theoretical predictions. The performance characteristics of the device demonstrate that practical, stable, and efficient operation of continuous-wave SROs at watt-level output power can be readily achieved in conventional birefringent materials by exploiting the intracavity pumping approach.