A diffractive having a grating period that exhibits significant polarization selectivity is used as a polarizing beamsplitter for obliquely incident polarized light. The grating is preferably a subwavelength of the illuminating beam and is preferably designed to substantially transmit transverse magnetic...http://www.google.com/patents/US6426837?utm_source=gb-gplus-sharePatent US6426837 - Diffractive selectively polarizing beam splitter and beam routing prisms produced thereby
