INTRACAVITY FREQUENCY BOUBLING OF PICOSECOND LASER IN A CONFOCAL UNSTABLE RESONATOR
共焦非稳腔中ps激光的内腔倍频

Considering the influence of angular acceptance angle of doubling crystal on the SHG conversion efficiency,a mode locked Nd:YAP laser with a positive branch confocal unstable resonator is designed.Therefore,a fully phase matching is realized when the parallel beam pass through the nonlinear crystal.Using BBO and KTP as intracavity frequency doubled generators,a highly efficient SHG conversion of 80.6% and 60.2% are obtained,respectively,and several tens millijoule green output is obtained.At the same time,some relative parameters are measured experimentally.