Fresnel reflection (source code)

= Fresnel reflection
{c}

The specular reflection of a wave at a planar dielectric interface with amplitudes described by the <Fresnel equations>. Below the <critical angle>, the reflected fraction is generally nonzero even when transmission is allowed; above the critical threshold, ideal lossless <total internal reflection> has unit reflected power. The reflected electric-field sign depends on polarization and the chosen basis conventions.