Confinement losses in microstructured optical fibers

We describe a multipole formulation that can be used for high-accuracy calc ulations of the full complex propagation constant of a microstructured opti cal fiber with a finite number of holes. We show how the imaginary part of the microstructure, which describes confinement losses not associated with absorption, varies with hole size, the number of rings of holes, and wavele ngth, and give the minimum number of rings of holes required for a specific loss for given parameters. (C) 2001 Optical Society of America.