Study On Surface Plasmon Polaritons Sensor

Sensors play important roles in our daily life. The surface plasmon sensor is widely used in many fields such as food inspection, clinical medicine, environmental monitoring, etc. Because of its characteristics such as label-free, high sensitivity, real-time monitoring, no damage, so it has a broad space for development and application areas. Therefore,designing and researching of the surface plasmon sensor is a hot point in the sensing field.With the rapid progress of nanotechnology in recent years, more and more people research the properties of optical nanowires and its production. Currently, optical nanowires are one of the most representative structures of micro-nano optical devices structure.Therefore, the sensing performance of surface plasmon sensors based on optical nanowires is very worthy of research.This paper mainly introduces the following work: Firstly, We summarize the development history of surface plasmon sensors, the common surface plasmon sensors and the basic theory and manufacturing process of optical nanowires. Second, we derivate of excitation conditions for surface plasmons from the Maxwell equations and metal-dielectric systems and introduced the characteristic length parameters of the surface plasmon. Then we briefly summarize the measurement methods of the surface plasmon sensors currently used.Next, we proposed three kinds of sensor structures based on surface plasmon: single silver nanowire structure, nanofiber with silver-plated structure and metal silver nanowire with nanofiber double-line structure.We use the finite element method and the COMSOL simulation tool to calculate the sensitivity of the intensity modulation method for these three structures from the light field analysis of the surface plasmons and make a analysis of the influence of parameters on the various structures. The silver nanowires and nanofiber double-line structure in the strength of the detection method, the sensor's sensitivity can reach more than 1.2×103RIU-1. According to the phase detection method of the surface plasmon and the method of obtaining the phase by the coherent surface plasmon, we proposed a surface plasmon phase detection method device and calculated the sensitivities of the three sensing structures for phase detection. We also discussed the sensitivity parameter dependence of the phase detection and found that the sensitivity of the surface plasmonic sensor based on the silver-coated nanofibers can reach 1.9×106RIU-1.Nanofiber coating structure could greatly enhance the sensitivity of the phenomenon aroused our attention, then we presented the phenomenon explanation and data comparison for the improvement of sensitivity.Finally, we summarized and prospected the surface plasmon sensor based on optical nanowire in this paper.