Continuous-wave intracavity frequency-doubled Nd:YAG-KNbO3 blue laser at 473 nm

High power blue radiation obtained by intracavity frequency-doubling of a continuous wave diode end-pumped Nd:YAG laser operating on the 4F3/2 → 4I9/2 transition is reported. The maximum output power for the randomly polarized beam at 946 nm was 3.7 W for 9.5 W absorbed pump power at 808 nm; the slope efficiency with respect to the absorbed pump power was 44%. For the polarized fundamental radiation the maximum power was 1.1 W (26% optical-to-optical efficiency with respect to the absorbed power), the laser operating with 38% slope efficiency. Intracavity frequency-doubling by a 2.0-mm thick KNbO3 crystal placed in a linear resonator yielded 159-mW single-ended blue-output with optical conversion efficiency versus the absorbed pump power of 4.8%. Using a V-type resonator increased the blue power at 418 mW with 11.6% optical conversion efficiency in absorbed power; the laser optical conversion efficiency was 6.7%, while the conversion of the available infrared power reached 50%.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.