These are thin film polarizers constructed as a cube. Thin film polarizers utilize the polarization which occurs on reflection from a plane surface. By combining a large number of such surfaces in a stack it is possible to obtain useful extinction ratios. The s-polarization is more than 99% reflected while the p-polarization can be suppressed in the reflected beam and become 95% transmitted. Thin film polarizers can be optimized for a particular wavelength to give superior performance for laser applications.
