PHASE-MATCHING PROPERTY OPTIMIZATION USING BIREFRINGENCE TUNING IN SOLID-SOLUTIONS OF KTIOPO4 ISOMORPHS

We report here the linear and nonlinear optical properties of the soli d-solutions KTiOPxAs1-xO4 and Cs1-xKxTiOAsO4. Single domain crystals o f these solid solutions were grown using a high temperature solution g rowth technique. By varying the compositional parameter x, the optical birefringence of these crystals was tuned to achieve noncritically ph ase-matched type II frequency doubling of the 1.064 and 1.32 mum lines of Nd:YAG. Near optimal compositions for these two applications, and their associated phase-matching angles, temperature bandwidths and ang ular acceptances are presented. The birefringence of KTiOPxAs1-xO4 exh ibits a Vegard dependence on x, and the phase-matching property optimi zation amounts to an accurate determination of the partition coefficie nts for P and As suitable for crystal growth. For the Cs1-xKxTiOAsO4 s olid solution, a non-Vegard dependence of the crystal birefringence an d the cell constants was observed. This is believed to be due to the p referential occupation of the larger K(2) site by Cs.