Origin of the giant quadratic electro-optic effect in KTa1−Nb O3 single crystals

Abstract The quadratic electro-optic (EO) effect of KTa1−xNbxO3 single crystals were investigated in this paper. The quadratic EO coefficient (R11–R12) could reach as high as 1.07 × 10−14 m2/V2, which means that the induced refractive index change under an 500 V/mm electric field is 200 times bigger than that of LiNbO3. A Sellmeier dispersion model of the quadratic EO effect was proposed to analyze the origin of the giant quadratic EO effect in KTa1−xNbxO3 single crystals.