Study On Relationship Between Sensitivity And Mechanical Performance Of Optical Fiber Sensor

Compared with mechanical and electronic sensor, the fiber-optic sensor has had great development with its high sensitivity, large dynamic range, convenience, compactness and so on. Interferometric fiber-optic weak magnetic sensor and fiber grating strain sensor have become the hot topics in the field of research on the fiber-optic sensor technologies.The study target of this dissertation is to analyze the relationships between system sensitivity and mechanical parameters of transducer for the two kinds of sensors mentioned above. The main contents include:Firstly, the interferometric fiber-optic weak magnetic sensor was introduced. A mathematical model was presented to analyze the mechanical performance of the transducer for fiber-optic weak magnetic field sensors using finite element method. The resonant frequencies from the lowest mode up to the fortieth order mode were calculated. It was found that the transducer has the highest sensitivity at the 32nd order resonant frequency, which agrees with the experimental result. This indicates the validity of the model. It provides an effective method for the optimal design and implementation of the transducer, and the system sensitivity can be improved accordingly. The displacements of transducer with different sizes of magnetostrictive rings and different lengths of fiber wrapped on the ring were calculated through harmonic response analysis. The results are that maximum displacement of sensing transducer can be...