Calculations of air-guided modes in photonic crystal fibers using the multipole method

We demonstrate that a combination of multipole and Bloch methods is well suited for calculating the modes of air core photonic crystal fibers. This includes determining the reflective properties of the cladding, which is a prerequisite for the modal calculations. We demonstrate that in the presence of a sorption, the modal losses can be substantially smaller than in the corresponding bulk medium. (C) 2001 Optical Society of America.