Application Of Optical Fiber Microstructure In Liquid Level And Vibration Monitoring

In recent decades, the optical fiber sensing technology develop rapidly. Compared to traditional electronic or mechanical sensor, it has anti-corrosion, high temperature, anti-electromagnetic interference, high sensitivity and other fine features. It has been widely used in hundreds of physical quantities. It relates to the field of aerospace, military defense,civil engineering, energy, electricity, environmental security, health care systems.The main content of this paper is sensing properties of the SNS(single_mode-no_core-single_mode) structure as well as self-imaging effect theory analysis and simulation. Build the appropriate level of monitoring systems and vibration monitoring systems, respectively, the level and frequency of vibration monitoring. This study, the main achievements are:(1)Designed a tunable fiber laser based on self-image effect with SNS structure as a sensing head and filters for monitoring the liquid level in the external environment. Achieve level monitoring range 280 mm, sensitivity is about 26.6 pm / mm, linearityR2 = 0.9994.(2)We designed a vibration monitoring system based on SNS structure for vibration frequency measurement. Using a signal generator, PZT and cantilever structure constructed vibration simulation environment. And do vibration monitoring experimental study with wavelength demodulation respectively. At last, achieved a precise measurement of low-frequency vibration frequency of 200 Hz.