Abstract

Compact and efficient sources of stable single-frequency radiation in the green and blue spectral region are presented. Based on ultra-stable miniature Nd:YAG ring lasers oscillating at 1064 nm and the quasi-three-level transition at 946 nm, frequency doubling in external resonators is performed. Applying MgO:LiNbO₃ as nonlinear crystal, up to 1.1 W are generated at 532 nm, while 250 mW are achieved at 473 nm with KNbO₃. High conversion efficiencies and excellent long term stabilities are measured. Due to a semi-monolithic cavity for the frequency conversion, modehop-ffee frequency tuning of the visible radiation over several tens of GHz is possible.

© 1997 Optical Society of America