DEVELOPMENT OF THE NONLINEAR-OPTICAL CRYSTAL CSTIOASO4 .2. CRYSTAL-GROWTH AND CHARACTERIZATION

We report here the crystal growth and characterization of the new nonl inear optical crystal CsTiOAsO4 (CTA). We have studied the Cs2O-TiO2-A s2O5 ternary and identified the phase field within which orthorhombic CTA can be crystallized. Large inclusion-free single crystals measurin g up to 30x20x25 mm3 can be readily grown using the Cs5As3O10 self-flu x. As-grown CTA crystals have the same crystal facets as KTP, although they tend to be multidomain. We present here two techniques for remov ing these domains: by trivalent oxide dopings and by ferroelectric pol ing. The refractive indices, nonlinear optical coefficients, electro-o ptic coefficients and dielectric properties of single domain CTA cryst als are reported. Compared to the crystal KTiOPO4, the smaller birefri ngence of CTA makes it particularly suitable for frequency doubling fu ndamental wavelengths between 1.3 and 1.5 mum. Our results suggest tha t CTA should find practical applications in electrooptic and in freque ncy conversion applications, such as optical parametric oscillators an d compact diode-pumped solid state lasers.