Large quadratic electro-optic effect in K0.99Li0.01Ta0.60Nb0.40O3 single crystal

Single crystal paraelectric K0.99Li0.01Ta0.60Nb0.40O3 is grown with a room-temperature Curie temperature (Tc). The parameters of the Sellmeier dispersion equation were determined. A large quadratic electro-optic (QEO) effect was observed. The QEO coefficient R11 reaches as high as 2.48 × 10−15 m2 V−2 around Tc. The induced refractive index change under an electric field of 500 V/mm is 40 times bigger than that of commonly used LiNbO3. The large QEO coefficient makes single crystal K0.99Li0.01Ta0.60Nb0.40O3 a promising candidate in optical devices.

► High quality paraelectric K0.99Li0.01Ta0.60Nb0.40O3 single crystal was grown.
► Sellmeier dispersion equation of the crystal was obtained.
► Large quadratic electro-optic effect was observed near Curie temperature.
► Quadratic electro-optic coefficient R11 reaches ∼10−15 V2 m−2.