Abstract

Nonlinear second-harmonic generation (SHG) and sum-frequency mixing (SFG) in nonlinear crystals are the most important methods for obtaining laser radiation at many wavelengths, in particular in the visible using solid-state lasers. Quasi phase matching (QPM) using periodically-poled (PP) crystals yields the highest conversion efficiency. One difficulty of QPM is its narrow spectral acceptance, which often only extends over a few tens of GHz. In order to achieve optimum conversion efficiency, the pump laser needs to be sufficiently narrow-band, which is not always the case, in particular for high-power lasers. In our SHG experiment, we are doubling cw light at 1178 nm to obtain up to 5 W at 589 nm, and our conversion efficiency is limited by the pump laser bandwidth.

© 2007 IEEE