Efficient and broadband Terahertz plasmonic absorbers using highly doped Si as the plasmonic material

The property of highly doped Si as the plasmonic material in the THz regime is analyzed, based on which the design of efficient and broadband Terahertz plasmonic absorbers is proposed and the performance of these absorbers is numerically investigated. Numerical results from the reflection spectra demonstrate that these structures exhibit high absorption in the terahertz frequencies with large bandwidth and high tunability. It is also shown that the same level of absorptivity and bandwidth can be achieved when the top layer of highly dopes Si stripes are replaced with regular metal materials e.g. copper, highly facilitating the fabrication and practical use of the proposed structure in real Terahertz applications.