MoS$_2$ Broadband Coherent Perfect Absorber for Terahertz Waves

We present a comprehensive analysis of terahertz waves propagation through a bulk MoS
₂
crystal slab. It is shown that broadband coherent perfect absorption can be achieved and the coherent absorptivity can be adjusted from 1.57% to 99.97% by means of phase modulation. Moreover, the relative bandwidth for over 90% coherent absorptivity can be as wide as 179%. By increasing the doping rate in MoS
₂
crystal, the coherent absorptivity spectrum exhibits a clear blueshift whilst the peak coherent absorptivity remains over 99.9%. Full-wave numerical simulations are further carried out to confirm the validity of our theoretical analysis.