Patent ID: 7139128
Filing Date: 2006-11-21
Classification: G02B

Abstract:
1. A reflective diffraction grating for processing electromagnetic radiation, the radiation having a wavelength λ and a TM-polarized portion, comprising: a substantially reflective surface comprising a plurality of grooves each having a width aligned in a first direction, and a plurality of ridges each having a width aligned in the first direction, the grooves and ridges being alternately disposed along the surface, and each of the grooves being adapted to propagate and reflect a waveguided portion of the TM-polarized portion of the radiation, and each of the grooves being adapted to provide a phase delay to the guided portion of the TM-polarized portion of the radiation, relative to a non-guided portion of the TM-polarized portion of the radiation reflected by the ridges, such that the zeroth diffraction order of the TM-polarized portion of the radiation is substantially canceled by destructive interference; a dielectric material having an index of refraction disposed on at least a portion of the reflective surface; and an overcoat layer disposed on the dielectric material having an index of refraction equal n