title: Interferometric characterization of subwavelength lamellar gratings.
abstract: We propose a new, to our knowledge, method for determining the two main critical parameters of periodic one-dimensional lamellar structures, namely, linewidths and etched depths. The method is simple and requires only two measurements for the phase of the zero-transmitted order under two orthogonal polarizations. It is inspired by the analogy between subwavelength gratings and anisotropic homogeneous thin films. The method is tested with experimental data obtained with a Mach-Zehnder interferometer. Etched depths and linewidths derived from the interferograms and electromagnetic theory are compared with scanning-electron-microscope observations.
authors.affiliation: Laboratoire Charles Fabry de l'Institut d'Optique, Centre National de la Recherche Scientifique, BP 147, F-91403 Orsay cedex, France. philippe.lalanne@iota.u-psud.fr
authors.forename: P
authors.initials: P
authors.lastname: Lalanne
authors.forename: P
authors.initials: P
authors.lastname: Pichon
authors.forename: P
authors.initials: P
authors.lastname: Chavel
authors.forename: E
authors.initials: E
authors.lastname: Cambril
authors.forename: H
authors.initials: H
authors.lastname: Launois