Asymmetric excitation of surface plasmons by dark mode coupling

Xueqian Zhang; Quan Xu; Quan Li; Yuehong Xu; Jianqiang Gu; Zhen Tian; Chunmei Ouyang; Yongmin Liu; Shuang Zhang; Xixiang Zhang; Jiaguang Han; Weili Zhang

doi:10.1126/sciadv.1501142

Asymmetric excitation of surface plasmons by dark mode coupling

Sci Adv. 2016 Feb 19;2(2):e1501142. doi: 10.1126/sciadv.1501142. eCollection 2016 Feb.

Authors

Xueqian Zhang¹, Quan Xu¹, Quan Li¹, Yuehong Xu¹, Jianqiang Gu¹, Zhen Tian¹, Chunmei Ouyang¹, Yongmin Liu², Shuang Zhang³, Xixiang Zhang⁴, Jiaguang Han¹, Weili Zhang⁵

Affiliations

¹ Center for Terahertz Waves, College of Precision Instrument and Optoelectronics Engineering, and the Key Laboratory of Optoelectronics Information and Technology (Ministry of Education), Tianjin University, Tianjin 300072, China.
² Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115, USA.
³ School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK.
⁴ Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
⁵ Center for Terahertz Waves, College of Precision Instrument and Optoelectronics Engineering, and the Key Laboratory of Optoelectronics Information and Technology (Ministry of Education), Tianjin University, Tianjin 300072, China.; School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, OK 74078, USA.

Abstract

Control over surface plasmons (SPs) is essential in a variety of cutting-edge applications, such as highly integrated photonic signal processing systems, deep-subwavelength lasing, high-resolution imaging, and ultrasensitive biomedical detection. Recently, asymmetric excitation of SPs has attracted enormous interest. In free space, the analog of electromagnetically induced transparency (EIT) in metamaterials has been widely investigated to uniquely manipulate the electromagnetic waves. In the near field, we show that the dark mode coupling mechanism of the classical EIT effect enables an exotic and straightforward excitation of SPs in a metasurface system. This leads to not only resonant excitation of asymmetric SPs but also controllable exotic SP focusing by the use of the Huygens-Fresnel principle. Our experimental findings manifest the potential of developing plasmonic metadevices with unique functionalities.

Keywords: Surface plasmons; asymmetric excitation; coupling; dark mode; near field; terahertz.

Publication types

Research Support, Non-U.S. Gov't