Numerical Modelling of Waveguiding Properties of Solid Core Photonic Crystal Fibers

Waveguiding properties of the higher order modes in solid core photonic crystal fibers are studied numerically. The dispersion diagram is calculated for glass fibers with refractive indices of 1.611 with a hole to period ratio of 0.5 and 0.8. It is shown that, below the cutoff of the higher order core modes, frequency regions exist within which these modes may propagate due to bandgaps in the cladding. In other words, the guiding effect in the solid core fibers may result both from total internal reflection and from resonant reflection by the periodic cladding.