A tunable single-frequency green laser based on a wedged Nd:YVO4 crystal and a KTP crystal

Abstract

Abstract A 532 nm single-frequency laser generated from a V-type oscillator configuration with a wedged Nd:YVO4 crystal and a KTP crystal is reported. An a-cut, 2.at% Nd:YVO4 crystal with a wedge angle of 10° and a KTP nonlinear crystal composes a novel birefringent filter. By adjusting the incident angle of the fundamental mode in the KTP, the laser can change from single-mode operation to two-mode oscillation. The maximum single-frequency output power of lasers with a 5 mm long KTP and a 7 mm long KTP are 284 and 148 mW, respectively, at pump powers of 2 and 1.1 W. The corresponding optical-to-optical conversion efficiencies are 14.2% and 13.5%. For the laser configuration with a 5 mm long KTP, the single-frequency operation at a pump power of 2 W is maintained within the temperature range of 18 °C to 24 °C, and the measured wavelength drift rate with the temperature is approximately 0.071 nm °C−1.