Research On Surface-Enhanced Raman Scattering Of Metal Nano-particles In THz Wave Band

Terahertz spectroscopy is located in infrared and microwave between, it belongs to with classical theory as the foundation of the electronics and the quantum transition theory as the foundation of the photonics overlapping area, because of the nature of appear a series of characteristic, therefore Terahertz waves in medicine, imaging, communication and astronomy, and many other fields, especially in the detection of biological macro molecules has outstanding application advantages. Surface enhanced Raman Scattering (SERS) technology in biological macromolecules in the inspection of the Terahertz and have a lot in common, the Terahertz wave and SERS combine to form a kind of based on the SERS Terahertz detection technology, biological macromolecules in the detection process has obvious advantages, not only can describe the molecular structure of biological macromolecules, but to detect the concentration of bio logical molecules. The surface of the metal nanoparticles electromagnetic enhancement effect is SERS basal part, using the Finite Difference Time Domain (FDTD) under the method of numerical calculation and simulation is the foundation. This paper Terahertz technology and the combination of SERS technology research proposition the following research:1) Analyze the forming principle of Raman scattering and the enhanced mechanism of SERS. We conducted an in-depth analysis for the combination of Terahertz technology and SERS technique based model.2) Study the differential forms of Maxwell equations describing electromagnetic fields in FDTD calculation. Focus on the analysis of the processing mode of dispersion characteristics of metal nano-particles in the approach of numerical calculation process.3) Research the enhancement factor of size distribution in the Thz-band of metal nano-particles using the FDTD method. Certify Terahertz wave technology and SERS technology combination of reasonable applicability from the basis. In the paper, we conducted simulation experiments of the electromagnetic enhancement of near-field Raman in "hot spot" of gold nano-particles dimer, and experimental results indicate electromagnetic enhancement factor of "hot spot" up to 106.