Optical damage resistant zirconium-diffused lithium tantalate ridge waveguides

Abstract

We report on the study of high-temperature zirconium in-diffusion in congruent z-cut lithium tantalate crystals. Zirconium (Zr) concentration profiles in samples prepared at different diffusion times and temperatures were investigated using secondary neutral mass spectrometry. From the diffusion profiles specific diffusion constant and activation energy were obtained. Zr-induced near-surface refractive index changes were extracted by means of prism-coupler measurements, and their correlation with Zr concentration was studied. Subsequently, low-loss optical ridge waveguides were diced and their resistance to photorefractive optical damage in the blue (405 nm) and green (532 nm) spectral ranges was measured, demonstrating damage thresholds in the multi-MW/cm^2 range.