1.59 W, single-frequency, continuous-wave optical parametric oscillator based on MgO:sPPLT

A watt-level, single-frequency, continuous-wave (cw) singly resonant optical parametric oscillator (OPO) based on MgO:sPPLT is described. Pumped in the green by a frequency-doubled cw diode-pumped Nd:YVO(4) laser at 532 nm, the OPO can provide up to 1.59 W of single-frequency idler output with a linewidth of ~7 MHz at pump depletions of as much as 67%. Using a compact ring resonator and optimized focusing in a 30 mm crystal, a singly resonant oscillation threshold of 2.84 W has been obtained under single-pass pumping. With a single grating period of 7.97 microm, continuous signal and idler coverage over 852-1417 nm is obtained by temperature tuning between 61 degrees C and 236 degrees C. The influence of thermal lensing on idler output power across the SRO tuning range is also verified.