Angle insensitive broadband terahertz wave absorption based on molybdenum disulfide metamaterials

Two-dimensional semiconductor materials may be of importance in the field of nanophotonics. We design a broadband terahertz (THz) absorber based on molybdenum disulfide (MoS2) metamaterial, consisting of a monolayer MoS2 concentric double rings and a metal mirror separated by a thin SiO2 layer. The plasma hybridization between two MoS2 rings can effectively increase the operating bandwidth of the device under normal circumstances. The absorption rate of the structure and the absorption bandwidth can be also tuned by temperature or voltage-controlled carrier concentration. The special geometry makes our design exhibit properties that are insensitive to the angle of incidence and the polarization state of the pump source. We believe that our devices may pave the way for the design of tunable sensors in terahertz and other frequency bands.