Analytic Spectral Integration of Birefringence-Induced Iridescence-Supplemental Material

In this section an overview of the physical theory of light propagating in an optically anisotropic medium is provided. We consider two homogeneous and magnetically isotropic adjacent media with their interface forming the XZ-plane in our coordinate system of choice and Ii = [0, cos θ, sin θ ]T being a ray propagating from the source medium (Y > 0) to the destination medium (Y < 0) with the incidence point being at the origin (see figure 2 in the paper). The incidence angle of Ii is then θ and we denote ηi as the effective index-of-refraction as perceived by the incident wave propagating in the source medium, which for isotropic materials is the refractive index of the source medium.