SCATTERING-MATRIX APPROACH TO MULTILAYER DIFFRACTION

A new modeling system to determine the optical response function of a multilayer structure with imposed periodicity in the plane of the laye rs, a multilayer diffraction grating, is described. This new model has two essential ingredients. This model is based on the well-establishe d coordinate transformation procedure developed by Chandezon et al. [J . Opt. Sec. Am. 72, 839-846 (1982)] in which a periodically modulated surface is transformed into a frame in which it is flat, permitting si mpler use of Maxwell's boundary conditions. Then, instead of using the conventional transfer-matrix method, we developed a scattering-matrix technique that permits the modeling of very thick (of the order of 1 mu m or greater) multilayer systems with many field components without numerical instability. Model programs have been developed based on th is new scattering-matrix approach and tested by comparison with other models and experimental data.