Study on Raman Spectrum Detection Method Based on Surface Enhanced Micro-nano Fiber

In this paper, an optical fiber Raman probe based on surface-enhanced particles is used to study the Raman spectroscopy of liquid trace substances. The optical fiber Raman detection probe uses a hollow-core fiber structure, and its air cavity as the optical excitation region of the surface-enhanced metal particles and the sample to be measured, it can form the high-efficiency action region of the sample and the excitation light, so as to achieve the perfect coincidence of the optical path and the sample cavity. Through the research on the output power of hollow fiber probe and the detection of Raman signal after inhaling different amount of samples and so on, the performance of the fiber Raman detection probe system is improved to the greatest extent. At the same time, the applicability of surface-enhanced metal particles is analyzed, and the best three kinds of metal sol, sample and hollow fiber are formed. The optimum measurement method was studied and tested. The melamine aqueous solution was measured by this method. The detection limit can reach 100 ppb. This Raman spectroscopic method is suitable for biological fluids or high-value fluids because of its small extraction of liquid samples. Its probe has low cost and is easy to mass production, which provides an effiective solution for the realization of all-optical fiber, portable and rapid detection of the whole Raman system.