Wave coupling theory of the quadratic electro-optic effect in a linear absorbent medium

Starting from Maxwell's equations and considering the quadratic electro-optic effect as a perturbation, we present a generalized wave coupling theory of quadratic electro-optic effect in linear absorbent centrosymmetric medium. We use a KLTN crystal as an example for studying the influences of linear absorption on the amplitudes and phases of the two electromagnetic wave components of electro-optic modulation.