In order to improve integration density, it is essential to develop a nano-scale optical waveguide
which is the key element to build varies of optical components. In this paper, a novel cylindrical hybrid
plasmonic waveguide, which has an air core surrounded by a metal layer and a silicon layer, is
proposed to achieve nano-scale confinement of light at the operating wavelength of 1550nm. And there
is a low-index material nano-layer between the metal layer and the silicon layer, in which the field
enhancement provides a nano-scale confinement of the optical field. The relations between the
characteristics of the bound modes, including the effective mode indices, propagation lengths, mode
sizes, mode shapes and parameters of the plasmonic waveguide are numerically investigated in detail.
The simulation results show that the nano-scale confinement can be realized and the proposed hybrid
plasmonic waveguide has a potential application in high density photonic integration.
Keywords: Surface Plasmon, Mode confinement, Subwavelength structure