Polarization-maintaining Fiber Stress Sensor And Sagnac Interferometer Of Polarization-maintaining Fiber

Polarization maintaining fiber(PMF)has been widely used in optical fiber communication and sensing technology as transmission fiber and sensing element.As transmission fiber,it has great polarization maintaining ability;as sensing element,it has been used in optical sensing fields,such as distributed stress sensing,optical fiber gyro and optical fiber current transformer.It had great significance to research the transmission characteristic and sensing characteristic of PMF.In this thesis,we researched the stress sensing properties of PMF and stability of Sagnac interferometer of PMF.The results and innovation points as follow(1)Based on elastic mechanics,we solved the stress distribution of fiber cross section under the lateral stress,and got the refractive index distribution.According to elastic-optic effect,we concluded the influence of the stress;(2)Considering the inherent birefringence of PMF is large,the different of stress coordinate system and the inherent birefringence coordinate system,we calculated the diagonal matrix of the refractive index matrix,and got the influence of external stress against PMF;(3)And we produced extrusion mechanism,completed experiment that can measure the magnitude and direction of stress;(4)Used the above theories,we calculated the output of PMF Sagnac interferometer by external stress,and the anti-jamming performance of PMF was analyzed,and tested by experiment.