Influence of Length of Opposing bi-Au Cone-Tips and Different Environment on Field Enhancement in Feed Gap  

作　　者：李旭峰 吴世法 

机构地区：[1]School of Physics and Optoelectronic Technology, Dalian Univers,ty of Technology, Dalian 116024

出　　处：《Chinese Physics Letters》2007年第10期2891-2894,共4页中国物理快报（英文版）

基　　金：Supported by National Natural Science Foundation of China under Grant Nos 30270367.

摘　　要：Electric field enhancement distributions encountered in feed gap of opposing bi-Au cone-tips is studied using a frequency-domain three-dimensional finite element method to solve Maxwell＇s equations of electric field distributions. Both the influences of cone-tip length and surrounding medium on electric field enhancement are investigated. The maximal enhancement value is discussed in terms of a simple physical model based on a standing wave on the tip surface associated with the antenna effect and surface plasmon. Simulated results demonstrate the enhancement is sensitive to the tip length. By selecting a suitably matched scale according to the incident wavelength, a large enhancement value can be observed within a small focused spot between the opposing tips permitting a high spatial resolution. The relative position of the opposing tips is also found for the optimum enhancement. All of the results suggest that our configuration is suitable for the site-specific Raman spectroscopic analysis at nanoscale.Electric field enhancement distributions encountered in feed gap of opposing bi-Au cone-tips is studied using a frequency-domain three-dimensional finite element method to solve Maxwell＇s equations of electric field distributions. Both the influences of cone-tip length and surrounding medium on electric field enhancement are investigated. The maximal enhancement value is discussed in terms of a simple physical model based on a standing wave on the tip surface associated with the antenna effect and surface plasmon. Simulated results demonstrate the enhancement is sensitive to the tip length. By selecting a suitably matched scale according to the incident wavelength, a large enhancement value can be observed within a small focused spot between the opposing tips permitting a high spatial resolution. The relative position of the opposing tips is also found for the optimum enhancement. All of the results suggest that our configuration is suitable for the site-specific Raman spectroscopic analysis at nanoscale.

关 键 词：RAMAN-SCATTERING SPECTROSCOPY MICROSCOPY 

分 类 号：O463.1[机械工程—光学工程]