Lateral shifts of optical beams on reflection by slanted chiral sculptured thin films

A theoretical investigation of lateral shifts of circularly polarized beams on reflection by a slanted chiral sculptured thin film (STF) is presented. First, the response of the slanted chiral STF to an obliquely incident plane wave is obtained by rigorous coupled-wave analysis; then, the angular-spectrum representation of beams is exploited for beam diffraction. Two types of lateral shifts of Gaussian beams are studied in detail. One is the lateral shift of a 2D co-handed beam that is mostly reflected due to the circular Bragg phenomenon. This lateral shift can be either forward or backward, depending on the angle of incidence. The other type of lateral shift is the Goos-Hänchen shift that occurs when a beam is totally reflected. The Goos-Hänchen shift comprises components both in and normal to the plane of incidence, when the incident beam is 3D Gaussian. The Goos-Hänchen shift is affected by both the structural handedness and the slantedness of the slanted chiral STF in nanotechnologically significant ways.