title: Fast modal method for crossed grating computation, combining finite formulation of Maxwell equations with polynomial approximated constitutive relations.
abstract: We present a modal method for the fast analysis of 2D-layered gratings. It combines exact discrete formulations of Maxwell equations in 2D space with polynomial approximations of the constitutive equations, and provides a sparse formulation of the eigenvalue equations. In specific cases, the use of sparse matrices allows us to calculate the electromagnetic response while solving only a small fraction of the eigenmodes. This significantly increases computational speed up to 100×, as shown on numerical examples of both dielectric and metallic subwavelength gratings.
authors.affiliation: ONERA-The French Aerospace Laboratory, Palaiseau, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Portier
authors.forename: Fabrice
authors.initials: F
authors.lastname: Pardo
authors.forename: Patrick
authors.initials: P
authors.lastname: Bouchon
authors.forename: Riad
authors.initials: R
authors.lastname: Haïdar
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Pelouard