On the optical quality of KTP crystals for nonlinear optical and electro-optic applications

Correlation between conditions of the top-seeded solution growth (TSSG) of potassium titanyl phosphate (KTP) crystals from self-fluxes and their optic al uniformity has been studied with respect to the crystal morphology, vari ation of stoichiometry and formation of point defects. It has been shown th at growth with pulling on X-oriented seeds yields single sector crystals ex hibiting the ideal transverse optical uniformity necessary for the design o f eye-safe optical parametric oscillations (OPO) and electro-optic elements based on the KTP crystals. Variation of stoichiometry has been studied usi ng powders synthesized by solid state reaction and measuring the Curie temp eratures of samples synthesized from batches with different starting compos itions. Growth from self-fluxes at lower temperatures is found to reduce th e concentration of potassium vacancies and their gradients and thus to supp ress the detrimental gray-tracking phenomenon during frequency doubling of the 1064 nm Nd:YAG laser radiation into the green. (C) 2001 Elsevier Scienc e B.V. All rights reserved.