Reflection and refraction at the surface of a chiral medium: comparison of gyrotropic constitutive relations invariant or noninvariant under a duality transformation

Abstract

Fresnel amplitudes for specular reflection and refraction at the surface of an isotropic, intrinsically nonmagnetic chiral medium are derived for sets of constitutive relations that are invariant or noninvariant under a duality transformation of the electromagnetic fields. The invariant set leads to a differential reflection curve of incident left and right circularly polarized light that is null at normal incidence and peaks beyond Brewster’s angle; the noninvariant set leads to maximum differential reflection in the vicinity of normal incidence and extends over a wide range of incident angles. Both sets lead to effectively equivalent descriptions of standard optical rotation and circular dichroism.