cw harmonic generation in the uv using a thin-film waveguide on a nonlinear substrate

Abstract
Phase‐matched second harmonic in the thin‐film and nonlinear Cerenkov radiation in the substrate have both been observed in the uv on a cw basis in a thin‐film waveguide structure consisting of an aluminium‐oxide film deposited on a quartz substrate. A sharp resonance in the second‐harmonic output was observed as the fundamental wavelength was tuned through the phase‐matching point. In contrast, the Cerenkov radiation was found to be broadly and continuously tunable and relatively intense.