An improved vector model for analyzing the diffraction field of sub-wavelength diffractive optical elements

An improved vector model to analyze the diffraction field of sub-wavelength diffractive optical elements is proposed. Based on the pioneer model put forward by Prof. M. Mansuripur, the Fresnel formula is further applied in our work to calculate the transmitted light field. A revised model is built, the updated vector diffraction formula is deduced and a computing example is given. Compared with Mansuripur's method, our method leads to results closer to those obtained by finite-difference time domain (FDTD), which is always considered as a more rigorous algorithm. Therefore, this paper provides the practical and fast algorithm for computing the diffraction light field of sub-wavelength diffractive optical elements.