Brewster's Angle
(θ_B)

Air
n_{1 = 1.0003}

Propagation

This demonstration directs incident light at a surface, at an angle equal to Brewster's angle for index of refraction values between 1.0 and 3.0. The incoming light is unpolarized, that is, it includes electric field vibrations of all orientations. When such light strikes a surface at precisely Brewster's angle, θ_B, the reflected portion of the beam is very polarized. The reflection contains only electric field vibrations that are parallel to the reflecting surface. The refracted beam contains all the other orientations of electric field vibrations. The measure of Brewster's angle is dependent only on the index of refractions of the two media.