Research On Nanostructure Surface Enhancement Of Electromagnetic Field

Raman spectroscopy based on the nonlinear Raman scattering have important applications and potential value in the area of chemical, biological, medical, food safety, national security and environment. However, the Raman scattering is a third-order nonlinear optical effect, generally the signal intensity is very weak making it difficult to detect. In recent years, with the development of Nanotechnology, the technology named SERS can amplifier the Raman signal in several orders of magnitude, making the foundation for low-cost, miniaturization, portability and popularity of Raman spectroscopy technology, and becoming a hot research topic in spectrometric detection with significance and application value.SERS is a powerful vibrational spectroscopy technique, which can achieve the highly sensitive detection of low concentration materials through the amplification of local electromagnetic fields by the excitation of localized surface plasmons. But currently the most widely used SERS substrate is made by vapor deposition, which has poor uniformity and their hot spot distribute randomly. It is an important development direction of current SERS technology that using electron beam lithography and nano-processing technology to produce large-area uniform enhancement chip. From this perspective, I made a model of metallic nanostructures can be used to produce SERS enhancement chips, with a simple structure and easy to manufacture planar features. Then I did numerical simulation using FDTD algorithm on three kinds of structures I designed. Simulation results show that the nano-block structure has better SERS enhancement factor which up to108in magnitudes. This structure is very promising for surface enhanced spectroscopy and sensing applications.