Linear and nonlinear optical properties of MgO:LiTaO3

We derive new temperature dependent Sellmeier equations for the extra-ordinary and ordinary refractive indices of 0.5% MgO-doped stoichiometric LiTaO3 crystal. The equations are based on quasi phase-matched frequency conversion measurements, as well as on interferometric measurements of the thermal expansion and thermal dispersion. These equations fit experimental data over wide spectral ranges: 0.35-6 mu m for the extra-ordinary wave and 0.375-3.75 mu m for the ordinary wave, from room temperature up to 200A degrees C. The nonlinear optical measurements set lower-limit values for the d (33), d (22), and d (24) elements of the second-order susceptibility tensor chi ((2)) of 12.9, 1.54, and 0.46 pm/V, respectively. The interferometric measurements enable one to determine the linear and quadratic expansion coefficients of 1.45762e-5 1/A degrees C, and 2.68608e-8 (1/A degrees C)(2), respectively. The Sellmeier equations are in good agreement with previously published data.