Holey optical fibers are microstructured silica fibers with an array of microscopic air holes that run down the full fiber length. If the size, spacing, and geometric arrangement of holes are chosen appropriately, these structures can be made to guide light. Guidance can be obtained by either of two distinct mechanisms: through photonic-bandgap effects related to certain periodic arrangements of large air holes or through volume average refractive-index effects that do not intrinsically rely on air-hole periodicity.
Now Peter Bennett, Tanya Monro, and David Richardson of the Optoelectronics Research Centre at the University of Southampton (Southampton, England) report they have fabricated mechanically robust holey fiber greater than 50 m in length. They have also demonstrated that the fiber can be spliced to conventional fiber types--an important issue for practical application of the technology. These technological advances permitted a detailed characterization of a holey fiber near 1.5 µm. The results may represent the first report of loss, nonlinearity and dispersion for holey fiber in the 1550-nm telecommunications window.
Paula M. Noaker