Analysis of Various Approaches for the Fabrication of Diffractive Optical Elements

Diffractive Optical Elements (DOEs) exist for a large range of applications. Usually DOEs are obtained by combining lithographic techniques and etching in order to achieve pre-determined phase patterns. That way, it is possible to shape or split laser beams with very high efficiencies. Indeed for binary element which consist of two phase levels (0 and π) the diffraction efficiency is around 75% and this efficiency can approach 100% for multilevel elements. Various illustrations of DOEs can be found in the literature for example using organic materials like photoresists or inorganic materials such as silica or chalcogenide layers [1].