Iterative optimization algorithm based on electromagnetic model for designing diffractive micro-optical elements

Abstract

An iterative optimization algorithm for designing two dimensions, finite aperture, aperiodic diffractive micro-optical elements based on rigorous electromagnetic computation model––the finite-difference time-domain method has been proposed. All aspects relating to the algorithm such as the finite-difference time-domain method, and the optimization process have been discussed in detail. Without any approximation based on scalar theory, the algorithm can present rigorous design results with reasonable computational cost. An aspherical surface lens and four kinds of off-axis lenses for normally incident TE mode have been designed to illustrate our algorithm. Meanwhile, we also consider the influence of quantized-lenses profiles on their diffraction performance.