Noncritical phase matching and photorefractive damage in Sc2O3:LiNbO3

The noncritical phase-matching temperature, Tpm, of Sc2O3-doped LiNbO3 was measured as a function of Sc2O3 concentration (0.0, 0.5, 1.0, and 1.5 mol % Sc2O3). Increasing the Sc2O3 concentration increased the phase-matching temperature, but to a lesser extent than reported in MgO:LiNbO3. The maximum phase-matching temperature was 46.5 °C in the 1.0 mol % Sc2O3:LiNbO3 crystal with an estimated temperature bandwidth of 1° cm. Photorefractive damage, determined by distortion in the transmitted beam, decreased with increasing Sc concentration, reaching a damage level comparable to that observed in 5.0 mol % MgO:LiNbO3 crystal in the 1.5 mol % Sc2O3:LiNbO3 crystal.