Blazed-binary diffractive elements with periods much larger than the wavelength

Blazed-binary optical elements with only binary ridges or pillars are diffr active components that mimic standard blazed-echelette diffractive elements . We report on the behavior of one-dimensional blazed-binary optical elemen ts with local periods much larger than the wavelength. For this purpose, an approximate model based on both scalar and electromagnetic theory is propo sed. The model is tested against electromagnetic-theory computational resul ts obtained for one-dimensional blazed-binary gratings with large periods. An excellent agreement is obtained, showing that the model is able to predi ct quantitatively the wavelength and the incidence-angle dependences of the diffraction efficiency of blazed-binary structures. (C) 2000 Optical Socie ty of America [S0740-3232(00)01607-0] OCIS codes: 050.1380, 050.1970, 050.1 950.