OPTICAL PARAMETRIC FREQUENCY-CONVERSION PROPERTIES OF KTIOASO4

The new nonlinear optical crystal KTiOAsO4 (KTA) is characterized and evaluated for use in optical parametric oscillator devices (OPOs) capa ble of generating tunable radiation in the 3-5 mu m region. Parametric tuning curves at the pump wavelength of 1.064 mu m are measured and c ompared to predictions based on published Sellmeier equations. Oscilla tion thresholds and damage thresholds of KTA are measured relative to its well-known isomorph KTiOPO4 (KTP). A KTA OPO was constructed which obtained a maximum conversion efficiency of 20% when pumped 2.6 times above threshold. Our results demonstrate that KTA is a promising mate rial for use in optical parametric devices. (C) 1994 American Institut e of Physics.