Study Of Surface Plasmon Resonance Sensor Based On Multi-hole Optical Fibers

In this paper, the development process of the surface plasmon resonance ?SPR?technology and the basic principle of the SPR based sensor are summarized systematically.On the basis of the theory,four structures of multihole optical fiber based SPR sensor are proposed and investigated. The influences of the fiber geometry parameters, the thicknesses of nano-films deposited on the air hole surface and selective coating on the hole on the sensor performance are analyzed in detail. The main works are summarized as follows:1. Two structures of optical fiber based SPR sensor are theoretically studied in detail with the finite element method ?FEM?. Both hollow-core fiber structures have many advantages, such as: simple structure, easy production and single transmission mode.Simulation results show that the gold film thickness and refractive index of the analytes have obvious effect on the resonant peak and the resonant wavelength is essentially the same with the changes of air hole size and pitch of holes. The sensitivity of the proposed SPR sensors can reach 10-4.2. Two multihole fiber optic SPR sensor structures with a high refractive index core are proposed in the paper. Discussion the sensing fiber geometry parameters, the gold film thickness, refractive index of the sample parameters on the transmission characteristics of the sensor shows that a high refractive index thin TiO₂ film deposited on the gold film resulting in that the operating wavelength of the sensor can be adjusted to near-infrared, the loss of sensors can be greatly reduced, and the sensitivity has been significantly improved. The numerical results indicate that the refractive-index resolution of 2.7×10-5 ?S?370 / RIU? for aqueous analytes can be achieved by the TiO₂ layer based multihole optical fiber SPR sensor.