title: Guidance properties of low-contrast photonic bandgap fibres.
abstract: We investigate the guidance properties of low-contrast photonic band gap fibres. As predicted by the antiresonant reflecting optical waveguide (ARROW) picture, band gaps were observed between wavelengths where modes of the high-index rods in the cladding are cutoff. At these wavelengths, leakage from the core by coupling to higher-order modes of the rods was observed directly. The low index contrast allowed for bend loss to be investigated; unlike in index-guiding fibres, anomalous "centripetal" light leakage through the inside of the bend can occur.
authors.forename: A
authors.initials: A
authors.lastname: Argyros
authors.forename: T
authors.initials: T
authors.lastname: Birks
authors.forename: S
authors.initials: S
authors.lastname: Leon-Saval
authors.forename: C M B
authors.initials: CM
authors.lastname: Cordeiro
authors.forename: P
authors.initials: P
authors.lastname: St J Russell