Electromagnetic plane-wave response characteristics of non-axially excited slabs of dielectric thin-film hélicoïdal bianisotropic mediums

Thin-film hélicoïdal bianisotropic mediums (TFHBMs) are rotationally non-homogeneous mediums whose microstructure consists of parallel helical columns. We characterize here the plane-wave response of non-axially excited dielectric TFHBM slabs. The constitutive relations for the dielectric TFHBMs are substituted into the timeharmonic Maxwell curl equations, and a 4 x 4 matrix ordinary differential equation is obtained. The piecewise homogeneity approximation method is shown to be reasonably robust to solve the differential equation. Bragg reflection by non-axially excited dielectric TFHBM slabs is investigated, and transmission characteristics are examined. The effects of several key illumination and constitutive parameters on the response of non-axially excited dielectric TFHBM slabs are studied to elucidate trends in functional relationships. A TFHBM bilayer is presented as an example of a device based on non-axially excited dielectric TFHBMs. Keywords: sculptured thin films; hélicoïdal symmetry; structurally chiral mediums; local biaxiality; non-axial excitation; Bragg phenomena