Vector-based design of beam splitters using an iterative optimization algorithm

摘要

Motivated by the Gerchberg-Saxton algorithm , an iterative angular spectrum algorithm (IASA) 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 optimization process, the finite difference time domain method, and the angular spectrum propagation method, have been discussed in detail. Because of the iterative algorithm's ability to convergent quickly, the facility of choosing different target distributions and the high computational efficiency of the FDTD method, our method can get required design results in reasonable computation time. Two kinds of beam splitter for normally incident TE mode have been designed to illustrate our algorithm. Meanwhile, the influence of lenses profiles' quantity on their diffraction performance has been considered also.