A rigorous unidirectional method for designing finite aperture diffractive optical elements.

We have developed a rigorous unidirectional method for designing finite-aperture diffractive optical elements (DOE's) that employs a micro-genetic algorithm (microGA) for global optimization in conjunction with a 2-D Finite-Difference Time-Domain (FDTD) method for rigorous electromagnetic computation. The theory and implementation of this microGA-FDTD design method for normally incident TE illumination are briefly discussed. Design examples are presented, including a micro-lens, a 1-to-2 beam-fanner and a 1-to-3 beam-fanner.