Reflections gratings with binary profiles are presented. The binary gratings are composed of a minilattice with feature sizes comparable to the wavelength of the incident light. The overall structure is designed in such a way that it imitates a conventional blazed grating. With the help of the diffraction grating high deflection angles with high diffraction efficiency are possible. The principle of such gratings, both dielectric and metallic gratings, are discussed. Theoretical calculations are shown to be in good agreement with measurements. The limitations on the method, both fundamental and arising due to the manufacturing process, are examined. The generation of a variable phase delay with the help of binary features with sizes close to wavelength, can also be applied to make more complicated optical elements such as Fresnel Zone Lenses and kinoforms.
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