A plasmonic staircase nano-antenna device with strong electric field enhancement for surface enhanced Raman scattering (SERS) applications

作者：Li Ziyuan^*; Hattori Haroldo T; Parkinson Patrick; Tian Jie; Fu Lan; Tan Hark Hoe; Jagadish Chennupati

来源：Journal of Physics D: Applied Physics , 2012, 45(30): 305102.

DOI：10.1088/0022-3727/45/30/305102

In this paper, a staircase plasmonic nano-antenna device is analysed both theoretically and experimentally. The tapered nano-antenna cavity with a grating leads to electric field enhancement factor (EF) as high as 31 close to 830 nm. The integration of a metallic grating aids the coupling of light coming from the vertical direction to the nano-antenna, increasing the electric field in the nano-antenna by a factor of 3. The smallest air gap width between the metallic regions of the fabricated nano-antenna is about 35 nm, fabricated using focused ion beam system. The small air gaps in the nano-antennas can generate very high intensity electric fields which can be used in applications in biological sensing and imaging, nanoparticle manipulations and enhancement of nonlinear effects. In this paper, to experimentally demonstrate that with the integration of a well designed grating and reflectors, the resonance inside the nano-antenna cavity is increased significantly, we exploit one application of this device: the enhancement of surface enhanced Raman scattering (SERS). The present structure can lead to SERS EFs above 1 million.

• 出版日期2012-8-1