Abstract-Experimental realization of perfect terahertz plasmonic absorbers using highly doped silicon substrate and CMOS-compatible techniques

Ting Wang, Su Shen, Jianjun Liu, Yusheng Zhang, and Zhanghua Han
https://www.osapublishing.org/ome/abstract.cfm?uri=ome-6-2-523

We experimentally demonstrate that at terahertz frequencies perfect plasmonic absorbers made on a highly doped silicon platform can be easily realized, exhibiting near-zero dips in the reflection spectra. The unit cell of the absorber consists of a dielectric layer of SiO2 film sandwiched between a highly doped silicon wafer and the copper structures, in the form of either one-dimensional stripe array or two-dimensional cross array. The reflection spectrum of the proposed absorbers are characterized using a terahertz time-domain spectroscopy system and the experimental results are in good agreement with numerical simulations. The dependence of the absorption on the THz polarization for both the 1D and 2D absorbers are also investigated. The high performance together with the easy fabrication processes presented in this paper show that the plasmonic absorber holds high prospect in terahertz applications.

© 2016 Optical Society of America

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

Yusheng Zhang¹ and Zhanghua Han^1,a)
 HIDE AFFILIATIONS
1 Centre for Terahertz Research, China Jiliang University, Hangzhou 310018, China
a) zhanghua@outlook.com
AIP Advances 5, 017113 (2015); http://dx.doi.org/10.1063/1.4905888

http://scitation.aip.org/content/aip/journal/adva/5/1/10.1063/1.4905888

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.