Mode classification and degeneracy in photonic crystal fibers

A novel full vector model based on the supercell lattice method is presented to analyze photonic crystal fiber (PCF). From symmetry analysis waveguide modes, we classify PCF modes into nondegenerate or degenerate pairs according to the minimum waveguide sectors and their appropriate boundary conditions. We describe how the modes of the PCF can be labeled by step-index fiber analogs, with the exception of modes that have the same symmetry as the PCF. When the doublet of the degenerate pairs both have the same symmetry as the PCF, they will be split into two nondegenerate modes. (C) 2003 Optical Society of America.