Patent ID: 7408712
Filing Date: 2008-08-05
Classification: G03F

Abstract:
1. A polarization-selectively blazed, diffractive optical element comprising: a plurality of contiguous blaze structures, which extend along a given geometrical path and each of which have a width perpendicular to a direction of extension, said width being greater than the wavelength of the electromagnetic radiation for which the diffractive optical element is designed, and each of said blaze structures comprising a plurality of individual substructures, which are arranged adjacent to each other in the direction of extension according to a predetermined period, said substructures providing a blaze effect and each substructure having the shape, when viewed from above, of a closed geometrical figure whose dimension parallel to the direction of extension varies perpendicular to the direction of extension, but is always smaller than the wavelength of the electromagnetic radiation, and whose maximum dimension perpendicular to the direction of extension is greater than the wavelength of the electromagnetic radiation, wherein the filling ratio of the individual substructures in the direction of the extension relative to the period is selected such that, as a function of a position perpendicular to the direction of extension, the blaze effect is optimized for one of two mutually orthogonal polarization conditions of the electromagnetic radiation.