Linear electro-optical properties of tetragonal BaTiO3

Linear optical susceptibility and clamped linear electro-optical tensor coefficients of tetragonal BaTiO₃ are calculated using a formalism based on bond charge theory. Calculated values are in close agreement with experimental data. The covalent Ti-O bonds constituting distorted TiO₆ octahedral groups are found to be major contributors to the electro-optic coefficients making them more sensitive than the BaO₁₂ groups for these properties. Orientations of chemical bonds play an important role in determining these properties.