title: Double photonic bandgap hollow-core photonic crystal fiber.
abstract: We report on the design, fabrication and characterization of hollow-core photonic crystal fiber with two robust bandgaps that bridge the benchmark laser wavelengths of 1064 nm and 1550 nm. The higher-order bandgap arises due to the extremely thin struts of the silica cladding and their fine-tuning relative to the apex size. The optimum strut thickness was found to be approximately one hundredth of the cladding pitch.
authors.affiliation: Centre for Photonics and Photonic Materials, Department of Physics, University of Bath, Bath BA27AY, UK. f.benabid@bath.ac.uk
authors.forename: Philip S
authors.initials: PS
authors.lastname: Light
authors.forename: François
authors.initials: F
authors.lastname: Couny
authors.forename: Ying Ying
authors.initials: YY
authors.lastname: Wang
authors.forename: Natalie V
authors.initials: NV
authors.lastname: Wheeler
authors.forename: P John
authors.initials: PJ
authors.lastname: Roberts
authors.forename: Fetah
authors.initials: F
authors.lastname: Benabid