title: Higher order guided mode propagation in solid-core photonic bandgap fibers.
abstract: We investigate higher order core-modes of solid-core photonic bandgap fibers experimentally and theoretically. We observe that for some wavelengths ranges the second mode is guided while the fundamental mode is not. We interpret this behavior in terms of the band diagrams and full numerical simulations, in good agreements with experiments. The sole guidance of the second, ring shaped modes observed at the edges of bandgaps could be of use for generation of vortex beams.
authors.affiliation: Institute of Photonics and Optical Science (IPOS), School of Physics, The University of Sydney, A28, NSW 2006, Australia.
authors.forename: Vincent
authors.initials: V
authors.lastname: Pureur
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Knight
authors.forename: Boris T
authors.initials: BT
authors.lastname: Kuhlmey