Dispersion equalisation of the modes of cylindrically symmetric few-mode optical fibres is investigated using equivalent planar waveguide representations. A numerical analysis based on the Characteristic Matrix Method has identified what we believe to be the first practical three-mode fibre with zero intermodal dispersion. This implies that the group velocities of each of the fibre’s three linearly polarized modes are equivalent. Dispersion equalisation is also confirmed in a power-law profile, as well as a novel two-mode fibre which operates within the third telecommunications windows. These few-mode fibres couldpotentially be used for long-haul telecommunications data links. In the case where themodes are not distinguished and are equally excited, the few-mode fibres could be used as larger core-radius alternatives to traditional single-mode fibres. If themodes are distinguished, eachmode could in theory be considered an independent data channel. All modal data channels would be equivalent for such dispersion-free few-mode fibres, notwithstanding differences in intramodal dispersion and mode crosstalk.
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