Analysis of anisotropic dielectric gratings using differential method

Abstract

An analysis algorithm is presented for the scattered field from a surface relief‐type anisotropic dielectric grating with an arbitrary permittivity tensor. The method based on the differential equation known widely as an analysis for isotropic dielectric gratings is extended here to the case where a dielectric grating contains an anisotropic medium. Further, an algorithm is proposed which avoids, by means of reorthogonalization of the initial value vectors, the difficulty in numerical treatment encountered by the differential method when the groove in the grating is deep and the number of expansion terms is large. By means of numerical examples, it is shown that stable numerical solutions can be obtained regardless of the depth of the grating grooves or the size of the expansion terms.