Hybrid low-permittivity slot-rib plasmonic waveguide based on monolayer two dimensional transition metal dichalcogenide with ultra-high energy confinement

A hybrid plasmonic waveguide design is proposed that incorporates a two-dimensional transition metal dichalcogenide monolayer covered slot-rib in between a cylindrical waveguide and a metal surface. A deep optical energy confinement (mode area ranging from λ²/1000000-λ²/100000) along with a reasonable propagation length (5μm-25μm) can be realized at the working wavelength of 1550 nm. In comparison with a traditional hybrid plasmonic waveguide, the proposed waveguide structure exhibits a smaller mode area as well as a higher figure of merit. Investigation on the influence of various two-dimensional materials on modal properties reveals that a larger permittivity provides a stronger field confinement. Owing to its excellent energy field confinement with low transmission loss, the proposed waveguide can be utilized in a variety of plasmonic devices such as compact plasmonic chips, high-integration plasmonic nano-lasers and high-sensitivity plasmonic detectors.