Metasurfaces,the ultra-thin media with extraordinary wavefront modulation ability,have shown great promise for many potential applications.However,most of the existing metasurfaces are limited by narrow-band and strong dispersive modulation,which complicates their real-world applications and,therefore require strict customized dispersion.To address this issue,we report a general methodology for generating ultra-broadband achromatic metasurfaces with prescribed ultra-broadband achromatic properties in a bottom-up inverse-design paradigm.We demonstrate three ultra-broadband functionalities,including acoustic beam deflection,focusing and levitation,with relative bandwidths of 93.3％,120％and 118.9％,respectively.In addition,we reveal a relationship between broadband achromatic functionality and element dispersion.All metasurface elements have anisotropic and asymmetric geometries with multiple scatterers and local cavities that synthetically support internal resonances,bi-anisotropy and multiple scattering for ultra-broadband customized dispersion.Our study opens new horizons for ultra-broadband highly efficient achromatic functional devices,with promising extension to optical and elastic metamaterials.

Hao-Wen Dong;Chen Shen;Sheng-Dong Zhao;Weibao Qiu;Hairong Zheng;Chuanzeng Zhang;Steven A.Cummer;Yue-Sheng Wang;Daining Fang;Li Cheng

Institute of Advanced Structure Technology,Beijing Institute of Technology,Beijing 100081,China;Department of Mechanical Engineering,The Hong Kong Polytechnic University,Hong Kong,China;Department of Electrical and Computer Engineering,Duke University,Durham,NC 27708,USA;Department of Mechanical Engineering,Rowan University,Glassboro,NJ 08028,USA;School of Mathematics and Statistics,Qingdao University,Qingdao 266071,China;Paul C.Lauterbur Research Center for Biomedical Imaging,Institute of Biomedical and Health Engineering,Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,China;Department of Civil Engineering,University of Siegen,D-57068 Siegen,Germany;Department of Mechanics,School of Mechanical Engineering,Tianjin University,Tianjin 300350,China

国家科学评论（英文版）

[1]Hao-Wen Dong;Chen Shen;Sheng-Dong Zhao;Weibao Qiu;Hairong Zheng;Chuanzeng Zhang;Steven A.Cummer;Yue-Sheng Wang;Daining Fang;Li Cheng-.Achromatic metasurfaces by dispersion customization for ultra-broadband acoustic beam engineering)[J].国家科学评论（英文版）,2022(12):179-189

Achromatic

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