Simulation Research Of The Raman Spectroscopy Enhancement Effect Based On Tip Structure

Raman spectroscopy is a kind of scattering spectrum,which is applied to the molecular detection and characterization of nano-materials.In recent years,this technology has become a conventional spectroscopic detection technique.The TERS technology has high spatial resolution and detection sensitivity.And it realizes the near field light and material interaction by the electromagnetic field effect,so it can analyze the components of nano-materials and obtain high-resolution morphological images.Therefore,TERS technology has broad prospects and deserves further study.The enhancement mechanism of TERS effect is analyzed,and the effect of TERS based on different probe tip structures are simulated.First of all,the key parameters in TERS enhancement effect are analyzed systematically.At the same time,the performance evaluation index of TERS enhancement effect is analyzed.Secondly,several new tip structures are proposed and different tip structural models are established by using the FDTD Solutions.Then,the electromagnetic field enhancement effects of several kinds of needle tip are analyzed by simulation.Finally,deep research is carried out on conical and inner concave arc tip,in which the tip material adopts tungsten and with silver-coated on the surface.And the TERS structure models are established based on the conical and concave arc tungsten tip with silver coating,and the golden sample particles.The electromagnetic simulation of TERS effect under different parameters is carried out,and the influence of laser incident angle,sample diameter and tip sample gap on the TERS effect are analyzed.The conclusions obtained in this paper can not only be used as reference for the preparation of probe tip with higher enhancement efficiency,but for the development of Raman spectrometer with ultrahigh sensitivity and spatial resolution.Moreover,it is helpful to improve the technical capability of Raman spectrum technology.