The influence of KTP"s thermal effects on the stabilization of a high-power diode-side-pumped all-solid-state QCW intracavity-frequency-doubled Nd:YAG laser and the compensating methods

The stabilization and modes of a high-power intracavity frequency-doubled Nd:YAG laser are numerically analyzed, the great influence of frequency-doubler’s thermal lensing on the stabilization and modes of this laser is demonstrated, and a compensating method is developed. A high-power QCW 532 nm green laser has been fabricated in the experiment, with a KTP crystal (θ=90°, φ=24.7°, 6×6×9.2mm, cut for high-temperature (80°C) application) as frequency-doubler. With the KTP crystal warmed up to 48.8°C and resonator parameters adjusted optimum according to the calculated thermal focal length of KTP crystal, a maximum 110W green laser is generated at 10.6kHz repetition rate, and its pulse width is 142ns, instability 2%, and optical-to-optical efficiency 11%.