Recently, Near-field Optics group, School of Physics, Peking University, led by Prof. Xing ZHU, has found a new way to realize plasmonic coupling between Ag nanowire and Bowtie antennas. Ag nanowire with the receiving and transmitting Ag bowtie antenna pairs at its incident and emission ends was used to realize an enhanced Plasmon emission with a factor of 45. The receiving and transmitting bowtie antenna pairs enhanced the Plasmon coupling and emission efficiencies of the Ag nanowire. And the maximum emission sensitively depended on the length of Ag nanowire, the arm length of bowtie antennas, and the incident angle of optical excitation. This enhanced Plasmon emission was also explored with analytical calculations using the impedance matching theory at optical frequency. Mr Zheyu Fang, a Ph.D. candidate, is the first author of the paper, under the supervision of Prof. Zhu.

This work is jointly completed by Peking University, National Center for Nanoscience and Technology, and Tübingen University, Germany. This work was supported by National Basic Research Program of China (973 Program) , National Natural Science Foundation, and SKL Mesoscopic Physics, Peking University.