title: Discontinuous wavelength super-refraction in photonic crystal superprism.
abstract: Experimental results on wavelength-dependent angular dispersion in InGaAsP triangular lattice planar photonic crystals are presented. An abrupt variation of the angular dispersion is observed for TM-polarized waves whose frequencies are comprised between those of the fourth and sixth allowed bands. According to the crystal period, the measured angle of refraction is found to either decrease or increase by 30 degrees within a wavelength range smaller than 30 nm. Experimental results are reproduced well from 2D finite difference time domain calculations. The observed phenomena are interpreted from the coupling of the incident light to different modes of the photonic crystal that travel with different group velocities and propagate in different directions within the crystal. Mode dispersion curves and mode patterns are calculated along with isofrequency curves to support this explanation. The observed discontinuous wavelength super-refraction opens a new approach to the application of superprisms.
authors.forename: Anatole
authors.initials: A
authors.lastname: Lupu
authors.forename: André
authors.initials: A
authors.lastname: de Lustrac
authors.forename: Abdelwaheb
authors.initials: A
authors.lastname: Ourir
authors.forename: Xavier
authors.initials: X
authors.lastname: Checoury
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Lourtioz
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Centeno
authors.forename: David
authors.initials: D
authors.lastname: Cassagne
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Albert
authors.forename: Frederic
authors.initials: F
authors.lastname: Pommereau
authors.forename: Lionel
authors.initials: L
authors.lastname: Legouezigou
authors.forename: Olivier
authors.initials: O
authors.lastname: Drisse
authors.forename: Odile
authors.initials: O
authors.lastname: Legouezigou
authors.forename: Estelle
authors.initials: E
authors.lastname: Deroin
authors.forename: Guang-Hua
authors.initials: GH
authors.lastname: Duan