Top seeded solution growth of KTiOPO4 (KTP) single crystals and their characterisation

Single crystals of the nonlinear optical material KTiOPO4 have been grown from K6P4O13 flux with a small addition of MoO3 using the TSSG technique out of a three zone furnace. Clear and transparent crystals measuring up to 3×2×2 cm3 were obtained at cooling rates of 1–3°C day−1 in 2–3 weeks time. Initial surface dissolution appears necessary to achieve flaw-free growth immediately off a seed. Seed orientation [001] exhibited a smaller capping region. Circular growth steps observed on the faces were studied using AFM. The lattice parameters were measured using X-ray powder diffraction analysis. Defects in the grown crystals were observed using SEM.