Critical modeling issues relating to rigorous boundary element method (BEM) analysis of diffractive optical elements (DOEs) are identified. Electric-field integral equation (EFIE) and combined-field integral equation (CFIE) formulations of the BEM are introduced and implemented. The nonphysical interior resonance phenomenon and thin-shape breakdown are illustrated in the context of a guided-mode resonant subwavelength grating. It is shown that modeling such structures by using an open geometric configuration eliminates these problems that are associated with the EFIE BEM. Necessary precautions in defining the incident fields are also presented for the analysis of multiple-layer DOEs.
© 2001 Optical Society of America
(050.1940) Diffraction and gratings : Diffraction
(050.1970) Diffraction and gratings : Diffractive optics
(050.2770) Diffraction and gratings : Gratings
(260.1960) Physical optics : Diffraction theory
(260.2110) Physical optics : Electromagnetic optics
Jon M. Bendickson, Elias N. Glytsis, Thomas K. Gaylord, and Andrew F. Peterson, "Modeling considerations for rigorous boundary element method analysis of diffractive optical elements," J. Opt. Soc. Am. A 18, 1495-1506 (2001)