Dynamic manipulation of electromagnetic(EM)waves with multiple degrees of freedom plays an essential role in enhancing information processing.Currently,an enormous challenge is to realize directional terahertz(THz)hol...Dynamic manipulation of electromagnetic(EM)waves with multiple degrees of freedom plays an essential role in enhancing information processing.Currently,an enormous challenge is to realize directional terahertz(THz)holography.Recently,it was demonstrated that Janus metasurfaces could produce distinct responses to EM waves from two opposite incident directions,making multiplexed dynamic manipulation of THz waves possible.Herein,we show that thermally activated THz Janus metasurfaces integrating with phase change materials on the meta-atoms can produce asymmetric transmission with the designed phase delays.Such reconfigurable Janus metasurfaces can achieve asymmetric focusing of THz wave and directional THz holography with free-space image projections,and particularly the information can be manipulated via temperature and incident THz wave direction.This work not only offers a common strategy for realizing the reconfigurability of Janus metasurfaces,but also shows possible applications in THz optical information encryption,data storage,and smart windows.展开更多
基金This study was supported by the National Key Research and Development Program of China(2017YFA0700202,2021YFB2800701)National Nature Science Foundation of China(62288101,91963128,62071215,62071217,62027807,62035014)Fundamental Research Funds for the Central Universities,and Research Fund for Jiangsu Key Laboratory of Advanced Techniques for Manipulating Electromagnetic Waves.J.W.acknowledges the support from Xiaomi Young Scholar Program.
文摘Dynamic manipulation of electromagnetic(EM)waves with multiple degrees of freedom plays an essential role in enhancing information processing.Currently,an enormous challenge is to realize directional terahertz(THz)holography.Recently,it was demonstrated that Janus metasurfaces could produce distinct responses to EM waves from two opposite incident directions,making multiplexed dynamic manipulation of THz waves possible.Herein,we show that thermally activated THz Janus metasurfaces integrating with phase change materials on the meta-atoms can produce asymmetric transmission with the designed phase delays.Such reconfigurable Janus metasurfaces can achieve asymmetric focusing of THz wave and directional THz holography with free-space image projections,and particularly the information can be manipulated via temperature and incident THz wave direction.This work not only offers a common strategy for realizing the reconfigurability of Janus metasurfaces,but also shows possible applications in THz optical information encryption,data storage,and smart windows.
