Long-range channel plasmon polaritons in thin metal film V-grooves.

We numerically investigate the propagation characteristics of guided modes in a thin metal film V-groove embedded in a dielectric medium, with a particular emphasis on long-ranging channel plasmon polaritons (LR-CPPs). The LR-CPP shows several orders of magnitude larger propagation length than the previously studied short-range channel plasmon polariton (SR-CPP). Moreover, the LR-CPP possesses a peculiar mode cutoff mechanism when surrounding dielectric media are asymmetric and this makes its propagation characteristics very sensitive to index change of the surrounding dielectric media.