Ultra-broadband reflectionless Brewster absorber protected by reciprocity  

作　　者：Jie Luo Hongchen Chu Ruwen Peng Mu Wang Jensen Li Yun Lai 

机构地区：[1]School of Physical Science and Technology,Soochow University,Suzhou,215006,China [2]National Laboratory of Solid State Microstructures,School of Physics,and Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing,210093,China [3]Department of Physics,The Hong Kong University of Science and Technology,Clear Water Bay,Hong Kong,China [4]William Mong Institute of Nano Science and Technology,The Hong Kong University of Science and Technology,Clear Water Bay,Kowloon,Hong Kong,China

出　　处：《Light(Science & Applications)》2021年第5期931-940,共10页光（科学与应用)（英文版）

基　　金：Y.L.,R.P.,and M.W.acknowledge support from the National Key R&D Program of China under Grant No.2020YFA0211300,2017YFA0303702;National Natural Science Foundation of China under Grant Nos.11974176,11634005,11974177,61975078;J.Luo acknowledges support from the National Natural Science Foundation of China under Grant No.11704271;Natural Science Foundation of Jiangsu Province under Grant No.BK20170326;a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD);J.Li acknowledges support from the Research Grants Council of Hong Kong under Grant No.R6015-18.

摘　　要：The Brewster’s law predicts zero reflection of p-polarization on a dielectric surface at a particular angle.However,when loss is introduced into the permittivity of the dielectric,the Brewster condition breaks down and reflection unavoidably appears.In this work,we found an exception to this long-standing dilemma by creating a class of nonmagnetic anisotropic metamaterials,where anomalous Brewster effects with independently tunable absorption and refraction emerge.This loss-independent Brewster effect is bestowed by the extra degrees of freedoms introduced by anisotropy and strictly protected by the reciprocity principle.The bandwidth can cover an extremely wide spectrum from dc to optical frequencies.Two examples of reflectionless Brewster absorbers with different Brewster angles are both demonstrated to achieve large absorbance in a wide spectrum via microwave experiments.Our work extends the scope of Brewster effect to the horizon of nonmagnetic absorptive materials,which promises an unprecedented wide bandwidth for reflectionless absorption with high efficiency.

关 键 词：POLARIZATION ABSORBER DIELECTRIC 

分 类 号：O4[理学—物理]