Dual-band absorption enhancement of monolayer molybdenum disulfide by a tapered metamaterial waveguide slab

A dual-band absorption enhancement of monolayer molybdenum disulfide (MoS2) by a tapered metamaterial waveguide slab (TMWS) is presented. Due to the gradient width of TMWS, double absorption bands of monolayer MoS2 can be enhanced simultaneously via the fundamental waveguide mode resonance. The correlation between the selective absorption performances of the TMWS-based absorber and the resonant waveguide modes can be evaluated by using the impedance theory and the planar waveguide model. In addition, the influence of the structural parameters of the TMWS on the absorption spectra of the monolayer MoS2 is systematically studied.