Low-loss light transmission in a rectangular-shaped hybrid metal trench at 1550 nm.

A hybrid plasmonic waveguide consisting of a high-index dielectric core embedded inside a rectangular-shaped metallic trench is proposed and its guiding properties are investigated at the wavelength of 1550 nm. Numerical simulations based on the finite element method have demonstrated that the introduced dielectric core could greatly reduce the modal loss of the metal trench while maintaining strong confinement of light. The effects of dielectric core size, material of the cladding and the dielectric core on the modal properties have been systematically investigated. The proposed hybrid plasmonic structure can be realized employing fabrication techniques of the traditional metal trench waveguides and could be leveraged as important elements for highly-integrated photonic circuits.