COMPARATIVE INVESTIGATIONS OF Nb AND Ta DOPED KTiOPO₄ MATERIALS BY HIGH-RESOLUTION X-RAY DIFFRACTION. C.J.Eaton, P.A.Thomas, Department of Physics, University of Warwick,Coventry, CV4 7AL,UK K. B. Hutton, R.C.C.Ward, University of Oxford, Clarendon Laboratory,Parks Road, Oxford, OX1 3PU,UK

Doping of the KTiOPO₄ (KTP) family of materials with ions such as Ta and Nb yields promising non-linear optical materials with increased birefringence but modified physical properties, such as mechanical strength. In this work, 10% niobium doped KTP, and 1% tantalum doped KTP have been studied using high-resolution x-ray diffraction to investigate the crystal quality compared with that of pure KTP. Topographs and reciprocal- space maps are shown and indicate that there is a degree of mosaicity within the material, with both similar and differing d-spacings in the mosaic blocks. These microstructural features are discussed in relationship to the crystal growth and quality of doped KTP and the suppression of growth along the [100] direction in particular.

In addition, second-harmonic generation studies have been made to image the mosaic blocks, and energy-dispersive x-ray analysis has been performed to determine if dopant levels are homogeneous throughout the sample.