Bend Loss in All-Solid Bandgap Fibers Revisited

The rate of decay of the fundamental guided mode into the surrounding cladding in all-solid photonic bandgap fibers is investigated. Both a simple 1-D model and numerical calculations of realistic fibers show that the decay rate varies asymmetrically across the bandgaps, with larger values near the upper edge of the bandgap. The implications for modeling bend loss in these fibers are discussed.