Design of solid and microstructure fibers for suppression of higher-order modes

Hole-assisted fibers have been proposed for a number of applications, including low-bend-loss access transmission. Suppression of higher-order modes is essential in these designs, and is explained here as the result of index-matched coupling between core and cladding modes. This physical principle is shown to explain previous empirically optimized designs, and enables intuitive generalizations. The improved tradeoff between bend loss and suppression of higher-order modes in these designs is discussed. Novel solid and microstructure fiber designs with suppressed higher-order modes illustrate these principles.