A Polarization-Insensitive Broadband Metamaterial Absorber at the Optical Regime
SHI Jun-Xian1, ZHANG Wen-Chao1, XU Wan1, ZHU Qing1, JIANG Xia1, LI Dong-Dong1, YAN Chang-Chun1**, ZHANG Dao-Hua2
1Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116 2School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
Abstract：We present a polarization-insensitive broadband absorber which has a feature of metal-insulator-metal structures. The top metal layer consists of four-fan-rings-shaped gold. Simulations show that the absorber exhibits an absorption of nearly unity at the wavelength of 386.1 nm and a relative absorption bandwidth of 0.548, which refers to the ratio of the full absorption bandwidth over an absorption of 0.9 to the central wavelength. Meanwhile, the absorption is nearly independent of the polarized direction of the incident wave. This absorption bandwidth with insensitive polarization is widely reported to date for such metal-insulator-metal structures. Such a structure offers a way of realization of a polarization-insensitive broadband absorber ranging in ultraviolet-to-visible wavelengths.
2015, Vol. 32 
