title: Modal characteristics of coupled metallic nanoscale rectangular apertures.
abstract: We examine the modal characteristics of coupled metallic nanoscale rectangular apertures using a simple and accurate separation of variables method, recently proposed by us for a single aperture [Opt. Lett.33, 333 (2008)]. The study shows that the coupling between the antisymmetric surface plasmon polariton (SPP) modes of the two rectangular apertures results in a coupled SPP mode with very large propagation length, larger than 1 mm at the wavelength of 0.633 microm, provided the aperture size and the separation are sufficiently large. The effective indices and the propagation lengths of various coupled SPP modes are presented.
authors.affiliation: Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. triranjita@yahoo.co.in
authors.forename: Triranjita
authors.initials: T
authors.lastname: Srivastava
authors.forename: Arun
authors.initials: A
authors.lastname: Kumar