title: Long period grating resonances in photonic bandgap fiber.
abstract: We demonstrate the formation of stress-induced long period gratings (LPGs) in fluid-filled photonic bandgap fiber (PBGF). Based on our experimental results, simulations, and theoretical understanding of LPGs, we identify coupling to a guided LP(11)-like mode of the core and lossy LP1x-like modes of cladding microstructure for a single grating period. The periodic modal properties of PBGFs allow for coupling to the same mode at multiple wavelengths without a dispersion turning point. Simulations identify inherent differences in the modal structure of even and odd bands.
authors.forename: P
authors.initials: P
authors.lastname: Steinvurzel
authors.forename: E D
authors.initials: ED
authors.lastname: Moore
authors.forename: E C
authors.initials: EC
authors.lastname: Mägi
authors.forename: B T
authors.initials: BT
authors.lastname: Kuhlmey
authors.forename: B J
authors.initials: BJ
authors.lastname: Eggleton