title: Comparing the Fourier modal method with the C method: analysis of conducting multilevel gratings in TM polarization.
abstract: The coordinate transformation method (C method) with adaptive spatial resolution and the Fourier modal method (FMM) are compared in the case of conducting discontinuous multilevel gratings in TM polarization. A procedure permitting analysis of such gratings more efficiently with the C method than with the FMM is presented. The C method is observed to converge more rapidly than the FMM, whose instabilities are shown to harm the convergence in the aforementioned case.
authors.affiliation: Department of Physics, University of Joensuu, Finland. Tuomas.Vallius@joensuu.fi
authors.forename: Thomas
authors.initials: T
authors.lastname: Vallius