Vectorial mode characterization of microstructured optical fibers

We investigate the mode structure and dispersion properties of air-silica microstructured fibers using a fully vectorial numerical model. The transverse electric and magnetic modal fields are expressed as linear combinations of plane-wave type exponential functions. The same basis functions are used to approximate the refractive index of the cross section of the fiber. For fiber profiles composed of cylindrical or elliptical subregions with a constant refractive index (rods, holes, capilars etc.) the Fourier expansion coefficients are found analytically. Boundary conditions are included in the supercell approximation, and finally the model leads to an algebraic eigenproblem which is solved numerically.