Phase anisotropic laser mirrors

A description is given of a multilayer reflector which alters the phase of normally incident light in accordance with its polarization. This reflector is a thin-film Fabry–Perot interferometer in which one of the mirrors is a multilayer dielectric and the other is a metal strip grating whose period is less than λ. The distance between these mirrors is selected so as to ensure that the amplitudes of the reflection coefficients for two orthogonal linear polarizations are the same, but the phases are different. It is shown that the difference between the phases decreases on increase in the reflection amplitude. The results are given of a numerical calculation for a reflector with between two and sixteen dielectric layers.