Diffraction from tunable periodic structures: application for the determination of electro-optic coefficients

We discuss a method for measuring electro-optic coefficients by measuring d iffraction from a tunable grating. The method involves measuring the change s in the diffraction pattern of a reflection grating, where applied electri c fields of alternating direction induce changes in the index of refraction through the electro-optic effect. For certain geometries, these applied fi elds cause period-doubling effects that produce new peaks in the diffractio n pattern. Numerically calculated diffraction patterns are presented for th e assumptions of both homogeneous and inhomogeneous fields. Peak splitting, as a function of both the number of slits illuminated and the induced chan ge in the index of refraction, is observed and discussed. Finally, the usef ulness of our method for the measurement of electro-optic coefficients is d iscussed. (C) 2001 Optical Society of America.