Anisotropic protective coating for brewster angle windows

We propose what we believe is a new type of dielectric anisotropic coating of arbitrary thickness that can protect Brewster angle windows without degrading their optical quality. Such a coating may be fabricated as a multilayer two-component structure. The parameters of the structure, i.e., the dielectric permittivities of the components and their concentrations, are calculated. For ZnSe windows two examples of anisotropic coatings are presented. The optical quality of the multilayer films does not depend on their precise thickness, which makes them less sensitive to surface damage.