《bzhang_oe_2016》.pdf

Polarization-independent dual-band infrared perfect absorber based on a metal-dielectric-metal elliptical nanodisk array 1,2 2 2 2 3 Bingxin Zhang, Yanhui Zhao, Qingzhen Hao, Brian Kiraly, Iam-Choon Khoo, 1 2,* Shufen Chen, and Tony Jun Huang 1School of Optoelectronics, Beijing Institute of Technology, Beijing 100081, China 2Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA 3Department of Electrical Engineering, The Pennsylvania State University, University Park, PA 16802, USA *junhuang@ Abstract: We have designed and fabricated a dual-band plasmonic absorber in the near-infrared by employing a three-layer structure comprised of an elliptical nanodisk array on top of thin dielectric and metallic films. finite difference time domain (FDTD) simulations indicate that absorption efficiencies greater than 99% can be achieved for both resonance frequencies at normal incidence and the tunable range of the resonant frequency was modeled up to 700 nm by varying the dimensions of the three-layer, elliptical nanodisk array. The symmetry in our two-dimensional nanodisk array eliminates any polarization dependence within the structure, and the near-perfect absorption efficiency is only slightly affected by lar