Switchable optical element with Bragg mode diffraction

A theoretical model of a new electronically switchable grating design that uses a multilayer structure of an electro-optic (EO) material with an inter digitated-electrode type of array is proposed as an original technique for calculating the induced refractive index. It is shown that asymmetrical dis tribution of the electric field induces a slanted Bragg grating, which allo ws the slant angle to be switched electronically among more than two switch ing status. Parameters of the suggested design are calculated for a number of EO materials. A special case of frequency-based switching is anticipated for some polymer-dispersed liquid-crystal materials. (C) 2001 Optical Soci ety of America.