title: BLOCH modes dressed by evanescent waves and the generalized Goos-Hänchen effect in photonic crystals.
abstract: It is common knowledge that in an infinite periodic medium, for instance, an infinite photonic crystal, the direction of propagation of a monochromatic wave packet is given by the normal to the isofrequency diagram. We show that this is no longer true in a finite size medium, due to the existence of evanescent waves near the interfaces of the photonic crystal. We derive a renormalized isofrequency diagram giving the correct direction. We give a physical interpretation, showing that this phenomenon can be considered as a generalized Goos-Hänchen effect.
authors.affiliation: Groupe d'Etude des Semiconducteurs, Unité Mixte de Recherche du Centre National de la Recherche Scientifique 5650, Université Montpellier II, 34095 Montpellier Cedex 5, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Felbacq
authors.forename: Rafik
authors.initials: R
authors.lastname: Smaâli