1.9-W cw ring-cavity KTP singly resonant optical parametric oscillator.

We report high-power and single-frequency operation of a continuous-wave singly resonant potassium titanyl phosphate (KTiOPO(4)) optical parametric oscillator in a ring-cavity configuration. The ring singly resonant optical parametric oscillator threshold is 4.3 W. When the oscillator is pumped by 6.7 W of 532-nm radiation from an 11.2-W single-frequency resonantly doubled Nd:YAG laser, 1.9 W of single-axial-mode output is generated at the idler wavelength of 1039 nm.