Optical and electro-optic properties of potassium lithium tantalate niobate single crystals

Potassium lithium tantalate niobate single crystals with the composition of K_0.95Li_0.05Ta_1-x Nb_xO₃ (KLTN) 0.4<x<0.9, have been grown using the top seeded melt growth method. The dielectric, pyroelectric, and piezoelectric properties have been systematically investigated earlier to establish the quality of the crystals. Using the minimum deviation method the indices of refraction as a function of frequency at room temperature and the Sellmeier's dispersion parameters are determined. The Sénarmont compensator method and a modified Mach-Zehnder interferometer configuration were coupled with computer interfaced dynamic scanning to measure the linear (Pockels') electrooptic coefficients. Large electro-optic responses are obtained for the crystal with K _0.95Li_0.05Ta_0.4Nb_0.6O₃ composition at 1kHz: r₃₃ =216.7 [pm/V], r₁₃ = -21.2 [pm/V], and r_C= 242.9 [pm/V]. The high EO coefficients, high figure of merit (as EO modulator), and high laser damage threshold are some of the attractive features for their attractive applications as electro-mechanical-optical coupled devices.