中国物理B ›› 2019, Vol. 28 ›› Issue (10): 107802-107802.doi: 10.1088/1674-1056/ab3f99

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Cascaded plasmonic nanorod antenna for large broadband local electric field enhancement

Dou Zhang(张豆), Zhong-Jian Yang(杨中见), Jun He(何军)   

  1. Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China
  • 收稿日期:2019-06-13 修回日期:2019-07-14 出版日期:2019-10-05 发布日期:2019-10-05
  • 通讯作者: Zhong-Jian Yang E-mail:zjyang@csu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11704416) and the Hunan Provincial Natural Science Foundation, China (Grant No. 2017JJ3408).

Cascaded plasmonic nanorod antenna for large broadband local electric field enhancement

Dou Zhang(张豆), Zhong-Jian Yang(杨中见), Jun He(何军)   

  1. Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China
  • Received:2019-06-13 Revised:2019-07-14 Online:2019-10-05 Published:2019-10-05
  • Contact: Zhong-Jian Yang E-mail:zjyang@csu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11704416) and the Hunan Provincial Natural Science Foundation, China (Grant No. 2017JJ3408).

摘要:

We propose a cascaded plasmonic nanorod antenna for large broadband electric near-field enhancement. The structure has one big gold nanorod on each side of a small two-wire antenna which consists of two small gold nanorods. For each small nanorod, the enhanced and broadened optical response can be obtained due to the efficient energy transfer from its adjacent big nanorod through strong plasmonic near-field coupling. Thus, the electric field intensity of the cascaded antenna is significantly larger and broader than that of the individual small two-wire antenna. The resonant position, field intensity enhancement, and spectral width of the cascaded antenna are highly tunable by varying the geometry of the system. The quantum efficiency of the cascaded antenna is also greatly enhanced compared with that of the small antenna. Our results are important for the applications in field-enhanced spectroscopy.

关键词: surface plasmon, optical antenna, electric field enhancement, broadband, cascaded

Abstract:

We propose a cascaded plasmonic nanorod antenna for large broadband electric near-field enhancement. The structure has one big gold nanorod on each side of a small two-wire antenna which consists of two small gold nanorods. For each small nanorod, the enhanced and broadened optical response can be obtained due to the efficient energy transfer from its adjacent big nanorod through strong plasmonic near-field coupling. Thus, the electric field intensity of the cascaded antenna is significantly larger and broader than that of the individual small two-wire antenna. The resonant position, field intensity enhancement, and spectral width of the cascaded antenna are highly tunable by varying the geometry of the system. The quantum efficiency of the cascaded antenna is also greatly enhanced compared with that of the small antenna. Our results are important for the applications in field-enhanced spectroscopy.

Key words: surface plasmon, optical antenna, electric field enhancement, broadband, cascaded

中图分类号:  (Nanocrystals, nanoparticles, and nanoclusters)

  • 78.67.Bf
73.20.Mf (Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)) 42.25.-p (Wave optics)