A polarization-independent broadband terahertz absorber

A highly efficient broadband terahertz absorber is designed, fabricated, and experimentally as well as theoretically evaluated. The absorber comprises a heavily doped silicon substrate and a well-designed two-dimensional grating. Due to the destructive interference of waves and diffraction, the absorber can achieve over 95% absorption in a broad frequency range from 1 to 2 THz and for angles of incidence from 0 degrees to 60 degrees. Such a terahertz absorber is also polarization-independent due to its symmetrical structure. This omnidirectional and broadband absorber have potential applications in anti-reflection coatings, imaging systems, and so on. (C) 2014 AIP Publishing LLC.