Linear electrooptic coefficient r51 of tetragonal potassium lithium tantalate niobate K_0.95Li_0.05Ta_0.40Nb_0.60O₃ single crystal

The linear electrooptic r51 coefficient of tetragonal K_0.95Li_0.05Ta_0.40Nb_0.60O₃ single crystal was measured and reported. A modified AC modulating method coupled with high precision sample positioner, coherent light source, and phase-locked signal detection, was used to measure the electric field induced rotation of optical axis. The electrooptic r₅₁ coefficient was found to be exceptionally large, r₅₁ = (1.10 ± 0.14) × 10⁴ pm/V at room temperature. Altogether with high ferroelectric phase transition temperature (~440 K), good optical crystal quality, ultrahigh linear electrooptic r51 coefficient and low frequency dependency, the K_0.95Li_0.05Ta_0.40Nb_0.60O₃ single crystal offers significant application potential for various electrooptic devices.