Algorithm based on rigorous coupled-wave analysis for diffractive optical element design

Diffractive optical element design is an important problem for many applica tions and is usually achieved by the Gerchberg-Saxton or the Yang-Gu algori thm. These algorithms are formulated on the basis of monochromatic wave pro pagation and the far-field assumption, because the Fourier transform is use d to model the wave propagation. We propose an iterative algorithm (based o n rigorous coupled-wave analysis) for the design of a diffractive optical e lement. Since rigorous coupled-wave analysis (instead of Fourier transforma tion) is used to calculate the light-field distribution behind the optical element, the diffractive optical element can thus be better designed. Simul ation results are provided to verify the proposed algorithm for designing a converging lens. Compared with the well-known Gerchberg-Saxton and Yang-Gu algorithms, our method provides 7.8% and 10.8%, respectively, improvement in converging the light amplitude when a microlens is desired. In addition, the proposed algorithm provides a solution that is very close to the solut ion obtained by the simulated annealing method (within 1.89% error). (C) 20 01 Optical Society of America.