Indexed on: 20 Dec '18Published on: 20 Dec '18Published in: Nanotechnology
The tunable propagation properties of MoS2 supported hybrid surface plasmons waveguides based on the dielectric fiber-gap-metal substrate structures have been investigated by using the finite element method, taking into account the influences of structural parameters, the dielectric fiber shape and carrier concentration of MoS2 layer. The results reveal that as the dielectric fiber radius increases, the confinement of hybrid mode increases, and the losses show a peak. The shape of dielectric fiber affects the propagation properties obviously, with optimum structural parameter (larger value of elliptical parameter) the confinement and figure of merits increase, and the dissipation decreases simultaneously. In addition, as the carrier concentration of MoS2 layer increases, the modulation depth of absorption reaches more than 40%, and the propagation constants manifest obvious double peaks at the wavelengths of 610 nm (2.03 eV) and 660 nm (1.88 eV), coming from the excitons absorption of MoS2 layer. The results are very helpful to understand the tunable mechanisms of hybrid modes waveguide structures and design novel surface plasmonic devices in the future, e.g. absorbers, modulators, lasers and resonators. © 2018 IOP Publishing Ltd.