Channel plasmon-polariton modes in V grooves filled with dielectric

We investigated the effect of dielectric filling in a V groove on the propagation parameters of\udchannel plasmon-polariton (CPP) modes. In particular, existence conditions and critical groove\udangles, mode localization, field structure, dispersion, and propagation distances of CPP modes are\udanalyzed as functions of dielectric permittivity inside the groove. It is demonstrated that increasing\uddielectric permittivity in the groove results in a rapid increase of mode localization near the tip of\udthe groove and increase of both the critical angles that determine a range of groove angles for which\udCPP modes can exist. Detailed analysis of the field structure has demonstrated that the maximum of\udthe field in a CPP mode is typically reached at a small distance from the tip of the groove. The effect\udof rounded tip is also investigated