Design of a Photo-Excited Tunable Metamaterial Absorber with Polarization-Insensitive and Wide-Angle Absorption in Terahertz Regime

We present a photo-excited tunable terahertz matematerial absorber (MMA) with polarization-insensitive and wide-angle absorption. The MMA is a periodic array consisted of dielectric layer sandwiched with continue metal film and meander split-rings., where light-sensitive silicon (LSS) chip is embedded in four gaps of split-ring. Since the conductivity of LSS is sensitive for laser light power., the tunable function is easy to achieve for this MMA. The numerical simulations demonstrate that the absorption peak frequency of the designed MMA is varied from O.615THz to O.321THz by modulated LSS. In addition., the relative modulation bandwidth and absorption depth are 62.67% and 49.59%., respectively. Further simulations indicate that the MMA has polarization-insensitive and wide-angle absorption for both TE and TM modes.