Non-polarizing Beamsplitter Cubes

Non-polarizing cube beamsplitters are made of two right angle prisms cemented together with a partially reflecting surface on the internal (protected) face. The dielectric coatings hold the s- and p-polarization components to the same reflection-to-transmission ratio, typically 50:50, at designed laser wavelengths or over broadband 450-700 nm and 750-1100 nm ranges. Cubes are made mainly of BK7, with four sides anti-reflection coated, in several sizes, unmounted or mounted.