Research On Optical Fiber Sensing And Demodulation Technology Based On Microwave Photon Processing

Microwave photonics(MWP)can break the bottleneck issue in the electrical domain.This technology is extended to the direction of sensing.It combines the characteristics of optical fiber sensing such as small size and strong anti-interference ability with the mature microwave technology,as well as greatly improves the sensing structure.The demodulation speed also optimizes the demodulation rate of the proposed structure.In addition,the use of microwave photons to process signals also has wide bandwidth,low loss,and remote sensing.In this thesis the microwave photon sensing and demodulation system with different taps is studied,and the specific work is as follows:(1)The dual-tap microwave photon sensing and demodulation system is studied.Through the theoretical analysis of the double-tap MPF,which proves that the sensing signal can be directly detected by the power of the output microwave signal.Using dual FBGs to form a dual-tap microwave photon sensing and demodulation structure,the power of the output signal is measured experimentally to achieve the sensing and demodulation of the external pressure,and discuss the parameters that alter sensitivity is achieved to optimize the sensitivity.(2)The multi-tap microwave photon sensing and demodulation system is studied.According to the theoretical analysis of the multi-tap MPF,it is proved that signal can be attained by the center frequency of the system.The bias fusion coreless fiber structure is implemented the cutting of the BOS,forming a multi-tap microwave photon sensing and demodulation system.Through simulation,the refractive index intensify with the center frequency,and the detection of the refractive index is actualized.(3)The infinite-tap microwave photon sensing and demodulation system is studied.From the simulation,the parameters influence the system are procured.And certifying that the length of the fiber loop can be obtained through the FSR,and is certified from experiments.At the same time,the measurement accuracy is optimized by adding a reference fiber.