Flexible dual-band all-graphene-dielectric terahertz absorber

We report a polarization-insensitive dual-band tunable graphene absorber in the terahertz region, which is composed of a top patterned graphene and a gold ground plane, separated by a silicon dielectric layer. Numerical simulations verify the amplitude of the absorption peaks have reached 98.6% and 98.2% at 0.512THz and 1.467THz, respectively. It exhibits excellent performances with high absorptivity and wide incident angles for both transverse electric (TE) and transverse magnetic (TM) polarizations. The frequency and amplitude of the absorption peaks can be regulated by chemical potential of graphene via bias voltage. These characteristics provide great potential applications in imaging, detecting, and sensing in the terahertz regime. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement