FDTD for plasmonics:Applications in enhanced Raman spectroscopy  

作　　者：YANG ZhiLin LI QianHong RUAN FangXiong LI ZhiPeng REN Bin XU HongXing TIAN ZhongQun 

机构地区：[1]Department of Physics, Xiamen University, Xiamen 361005, China [2]Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China [3]Department of Chemistry, Xiamen University, Xiamen 361005, China

出　　处：《Chinese Science Bulletin》2010年第24期2635-2642,共8页

基　　金：supported by the National Natural Science Foundation of China(20703032,10625418,10874233 and 10904171);the National Basic Research Program of China(2009CB930703,2006DFB02020 and 2009CB9-30700);the Natural Science Foundation of Fujian Province of China(E0710028);the Hundred Talents Project of Chinese Academy of Sciences

摘　　要：The exact electromagnetic enhancement mechanism behind SERS,TERS,HERS and SHINERS is one of the issues focused on in the study of enhanced Raman spectroscopy.The three dimensional finite difference time domain method(3D-FDTD),which is widely used in nanoplasmonic simulations,not only provides us with a powerful numerical tool for theoretical studies of the ERS electromagnetic enhancement mechanism,but also serves as a useful tool for the design of ERS-active systems with higher sensitivities and spectral spatial resolution.In this paper,we first introduce the fundamental principles of FDTD algorithms,and then the size-dependent dielectric function of dispersive metallic material is discussed.A comparative study of FDTD and rigorous Mie evaluations of electromagnetic fields in the vicinity of a system of self-similar nanospheres shows an excellent correlation between the two computational methods,directly confirming the validity and accuracy of 3D-FDTD simulations in ERS calculations.Finally,we demonstrate,using a TERS calculation as an example,that the non-uniform mesh method can be more computationally efficient without loss of accuracy if it is applied correctly.The exact electromagnetic enhancement mechanism behind SERS, TERS, HERS and SHINERS is one of the issues focused on in the study of enhanced Raman spectroscopy. The three dimensional finite difference time domain method （3D-FDTD）, which is widely used in nanoplasmonic simulations, not only provides us with a powerful numerical tool for theoretical studies of the ERS electromagnetic enhancement mechanism, but also serves as a useful tool for the design of ERS-active systems with higher sensitivities and spectral spatial resolution. In this paper, we first introduce the fundamental principles of FDTD algorithms, and then the size-dependent dielectric function of dispersive metallic material is discussed. A comparative study of FDTD and rigorous Mie evaluations of electromagnetic fields in the vicinity of a system of self-similar nanospheres shows an excellent correlation between the two computational methods, directly confirming the validity and accuracy of 3D-FDTD simulations in ERS calculations. Finally, we demonstrate, using a TERS calculation as an example, that the non-uniform mesh method can be more computationally efficient without loss of accuracy if it is applied correctly.

关 键 词：增强拉曼光谱 FDTD法 应用 时域有限差分法 时域有限差分算法 电磁增强机理 SERS效应 有限差分模拟 

分 类 号：O625.65[理学—有机化学] TN011[理学—化学]