Breaking the glass ceiling: hollow OmniGuide fibers

Summary form only given. Telecommunications has continued to push optical fibers towards ever-more demanding applications-such as high bit rates, dense wavelength-division multiplexing (DWDM), and long distances-and in response there has been renewed interest in alternative fiber designs to lift fundamental limitations of silica fibers. A particularly exciting departure from traditional fibers are fibers based on photonic band gaps, forbidden frequency ranges in periodic dielectric structures that can confine light even in low-index or hollow regions. Two main classes of fibers have emerged using photonic band gaps: photonic-crystal "holey" fibers that use a two-dimensional transverse periodicity, and Bragg fibers that use a one-dimensional periodicity of concentric rings. We introduce a novel class of Bragg fibers: "OmniGuide" fibers, which can guide light within a hollow core by concentric multilayer films with the property of omnidirectional reflection.