Refractive index measurement of cerium-doped LuxY2−xSiO5 single crystal

► Principal refractive indices of biaxial LuxY2−xSiO5. ► Analytical results between 350 and 1100nm by using calculated dispersion coefficients. ► Nearly uniaxial behavior. ► Ellipsometric measurement of axial dispersion between 250 and 900nm. ► Importance in spectroscopic evaluation of crystal properties. Principal refractive indices of the biaxial cerium-doped LuxY2−xSiO5 (LYSO) crystal were determined with high accuracy at seven different wavelengths between 400 and 700nm using the classical minimum angle of deviation method. The reliability of the measured data permitted to deduce parameters of a common dispersion formula, by which the refractive indices can be extrapolated for wavelengths up to 1100nm, an important range for laser applications. The extent of axial dispersion was precisely measured by ellipsometry, its effects on the anisotropic refractive index has been calculated. Examples are given to demonstrate the influence of anisotropy on the operation of optical devices.