Brewster's angle

Dependence of the power reflectivity on the angle of incidence, if the light at 1064 nm wavelength impinges from air on a silica surface.

Brewster's angle is the angle under which p-polarized indicent light is almost completely transmitted. In the figure to the right, you can see that an air/silica interface has a reflectivity of zero for p-polarized light at ~56°. Brewster's angle is dependent on the ratio between refractive indeces, which in turn are dependent on the wavelength of the light.

Additional explanation.

Implications

• If your beam port is supplied with horizontally polarized light, make sure that your Brewster window is in the vertical direction (because you want that light to be completely transmitted, so it has to be parallel to the Brewster window).

  

  A stack of plates at Brewster's angle to a beam reflects off a fraction of the s-polarized light at each surface, leaving (after many such plates) a mainly p-polarized beam.

Brewster's angle - the angle under which p-polarized indicent light is almost completely transmitted.