Ultra-broadband absorber based on cascaded nanodisk arrays  

作　　者：Qi Wang Rui Li Xu-Feng Gao Shi-Jie Zhang Rui-Jin Hong Bang-Lian Xu Da-Wei Zhang 王琦;李瑞;高旭峰;张世杰;洪瑞金;徐邦联;张大伟(Engineering Research Centre of Optical Instrument and System,the Ministry of Education,Shanghai Key Laboratory of Modern Optical System,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]Engineering Research Centre of Optical Instrument and System,the Ministry of Education,Shanghai Key Laboratory of Modern Optical System,University of Shanghai for Science and Technology,Shanghai 200093,China

出　　处：《Chinese Physics B》2022年第4期83-89,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.61775140 and 62005165)。

摘　　要：An ultra-broadband perfect absorber consisting of cascaded nanodisk arrays is demonstrated by placing insulatormetal-insulator-metal nanodisks on insulator-metal film stacks.The absorber shows over 90% absorption in a wavelength range between 600 nm and 4000 nm under transverse magnetic(TM) polarization,with an average absorptivity of 91.5%and a relative absorption bandwidth of 147.8%.The analysis of the electric field and magnetic field show that the synergy of localized surface plasmons,propagating surface plasmons,and plasmonic resonant cavity modes leads to the ultrabroadband perfect absorption,which accords well with the results of impedance-matched analysis.The influences of structural parameters and different metal materials on absorption performance are discussed.Furthermore,the absorber is polarization-independent,and the absorption remains more than 90% at a wide incident angle up to 400 under TE polarization and TM polarization.The designed ultra-broadband absorber has promising prospects in photoelectric detection and imaging.

关 键 词：ultra-broadband absorption cascaded nanodiskarrays polarization-independent 

分 类 号：TB383.1[一般工业技术—材料科学与工程]