Brewster Windows are primarily used in laser cavities to produce a beam with a high degree of polarization purity. When unpolarized light is incident on an uncoated substrate at Brewster’s Angle, the reflected portion is completely S polarized and the transmitted portion is partially P polarized. Multiple passes through the substrate Substantially reduce the S component in the transmitted beam, resulting in a highly P polarized output. multi-layer thin Film Polarizer coatings can be applied to these substrates to greatly improve efficiency and extinction ratio on a single pass through the substrate. |