title: Optical guided waves at graded metal-dielectric interfaces.
abstract: Waveguides at interfaces with a linearly graded permittivity between a metal and a dielectric are studied. Analytic expressions for the dispersion relations, modes, losses, and cutoff wavelengths are derived and agree well with simulations. The gradation results in anomalous dispersion, a reduction in the energy velocity, and increased field confinement in the metal-dielectric transition region. These effects lead to increased propagation losses, which are sensitive to the spatial extent of the interface gradation.
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, Ontario M5S 3G4, Canada. brett.kruger@utoronto.ca
authors.forename: Brett A
authors.initials: BA
authors.lastname: Kruger
authors.forename: Joyce K S
authors.initials: JK
authors.lastname: Poon