Macro Bending Losses in Single-Cell Kagome-Lattice Hollow-Core Photonic Crystal Fibers

We report on numerical and experimental results on macro bending losses in single-cell Kagome-lattice hollow-core photonic crystal fibers. Fibers with different cladding layer numbers have been investigated. Results show that a cladding with at least two rings produces a reduction in bend sensitivity by more than one order of magnitude relative to a single layer cladding. This result is an original way to confirm the main role played by the inhibiting coupling mechanism in such microstructured fibers.