Brewster angle, θB
When an unpolarized planar electromagnetic wavefront impinges on a flat dielectric surface, there is a unique angle (θB), commonly referred to as Brewster angle, at which the reflected waves are all polarized into a single plane.
  1. Expression for Brewster @A00346@: \[\theta_{\text{B}} = arctan \frac{n_{2}}{n_{1}} = arctan \left (\frac{\varepsilon_{2}}{\varepsilon_{1}} \right)^{1/2}\] where n2 and n1 are the refractive indices of the receiving surface and the initial medium, respectively, and ɛ2 and ɛ1 are the relative static permittivities (formerly called dielectric constants).
  2. For a randomly polarized beam incident at Brewster @A00346@, the electric fields of the reflected and refracted waves are perpendicular to each other
  3. For a wave incident from air on water (n = 1.333), glass (n = 1.515), and @D01671@ (n = 2.417), the Brewster angles are 53, 57, and 67.5 degrees, respectively.
PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 310 (