Truncation of Angular Spread of Bragg Zones by Total Reflection, and Goos–Hänchen Shifts Exhibited by Chiral Sculptured Thin Films

Abstract

The total-reflection phenomenon is shown to restrict the angular spread of the Bragg phenomenon, when a plane wave is incident ona chiral sculptured thin film (STF) from an optically denser medium. Unlike the Bragg phenomenon, the total-reflection phenomenon is insensitiveto the structural handedness of the chiral STF. Mechanically tunable Goos–Hänchen shifts that are appreciable fractions of the wavelength are experienced by beams of finite transverse extent, in the total-reflectionregime.