Brewster angle

The angle θ (measured from the normal to the boundary) at which a plane wave polarized in the plane of incidence is totally transmitted when incident on a plane dielectric boundary. Given by tanθ = &sqr;e₂/e₁ where e₁, e₂ are the permittivities of the two media. For optical wavelengths, tan θ=n, the refractive index between the media. Also called polarizing angle. See also Brewster window