Abstract-Dual-band and polarization-insensitive terahertz absorber based on fractal Koch curves

Ma Yan-Bing (马岩冰)1, Zhang Huai-Wu (张怀武)1, Li Yuan-Xun (李元勋)1,2, Wang Yi-Cheng (王艺程)1, Lai Wei-En (赖伟恩)1 and Li Jie (李 颉)1

http://m.iopscience.iop.org/1674-1056/23/5/058102/pdf/1674-1056_23_5_058102.pdf

mayanbing_uestc@163.com

1 State Key Laboratory of Electronic Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
2 Institute of Electronic and Information Engineering, University of Electronic Science and Technology of China, Dongguan 523808, China

Ma Yan-Bing et al 2014 Chinese Phys. B 23 058102. doi:10.1088/1674-1056/23/5/058102
Received 9 July 2013, in final form 28 October 2013. Published 1 April 2014. 

We report the design, fabrication, and characterization of a dual-band and polarization-insensitive metamaterial absorber (MA), which consists of periodically arranged fractal Koch curves acting as the top resonator array and a metallic ground plane separated by a dielectric spacer. Compared with conventional MAs, a more compact size and multi-frequency operation are achieved by using fractal geometry as the unit cell of the MA. Both the effective medium theory and the multi-reflection interference theory are employed to investigate the underlying physical mechanism of the proposed terahertz MA, and results indicate that the latter theory is not suitable for explaining the absorption mechanism in our investigated structure. Two absorption peaks are observed at 0.226 THz and 0.622 THz with absorptivities of 91.3% and 95.6% respectively and good agreements between the full-wave simulation and experimental results are achieved.