Brewsters angle and oblique windows are a common product in our offerings. We have produced many different angles and diameters through the years. Call us to produce any angle you need. When light moves between two media of differing refractive index, generally some of it is reflected at the boundary. At one particular angle of incidence, however, light with one particular polarization cannot be reflected. This angle of incidence is Brewster's angle.
Brewster/Oblique windows are windows designed for use at Brewster's angle (usually uncoated). This is the angle where only incident p-polarized light has 0% transmission loss. They are and economical option for coupling linearly polarized light into sealed optical systems and to select the polarization of light traveling in optical cavities.
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 reduces 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.