Design and evaluation of diffractive optical elements; optimization byusing iterative angular spectrum approach and evaluation based onvector diffraction theory

摘要

Diffractive optical elements (DOE) are used for various purposes, such as a beam shaper, beam splitter and so on. Inorder to design DOEs, iterative Fourier transform algorithm (IFTA) is widely used. IFTA is fast and effectiveoptimization method and can handle large size data. In the IFTA, propagation in the far field and near field is describedby Fourier transform and Fresnel transform, respectively. Iterative angular spectrum approach (IASA) is one of iterativemethods based on angular spectrum technique. IASA adopt angular spectrum technique as expression of propagation innear field instead of Fresnel transform. Angular spectrum technique is based on scalar diffraction theory and satisfiesHelmholtz equation; therefore angular spectrum technique is the accurate method for the calculation of diffraction.