Fresnel Equations - Overview

Overview

When light moves from a medium of a given refractive index n₁ into a second medium with refractive index n₂, both reflection and refraction of the light may occur. The Fresnel equations describe what fraction of the light is reflected and what fraction is refracted (i.e., transmitted). They also describe the phase shift of the reflected light.

The equations assume the interface is flat, planar, and homogeneous, and that the light is a plane wave.