Microcavity Interferometric Fiber Optic Sensor And Demodulation Technology Research

Fiber Optical Sensing Technology, as a product of the technological development of the new world, has been developed a practical industry since Corning Incorporated manufactured useful optical fiber in1970s. There are now more than70kinds of optical fiber sensors, which are widely used in areas such as military, civilian, energy, traffic, healthcare industries etc. According to the analysis of the trend of Fiber Optical Sensing Technique, one of our main tasks is to develop new sensors that have more features; the other one is to push findings into practice to solve real problems.Based on these two points, and by a vast amount of reading, a new effective method of making multifunction sensor to measure refractive, strain and temperature is presented in this project. It is lucky that we have the opportunity to take a field test for strain gauge balance using the sensor we manufactured in the lab. Jobs completed in the project are summarized below.(1)For the structure we manufactured is Fabry-Perot, this paper gives a brief account of fiber sensor from definition, classification and application respects. Meanwhile, the development of F-P sensor, the interference principle and the common demodulation methods are analyzed.(2)A detailed introduction of the research is given. First is the factual basis of choosing F-P interferometer as the configuration of the multifunction sensor. Second is the process of manufacturing F-P cavity by157nm laser. Third is the sensing mechanism, which offers proof for the viability of the experimental scheme. The experiment result is that: the sensitivity of refractive is43.093dB/RIU, and the sensitivity of temperature between90℃and380℃is10.965pm/℃, the linearity of strain sensitivity is also good.(3)By using Fourier Transform demodulation, the strain sensor is used on strain gauge balance successfully. The result is satisfying.(4)The software simulation of three-wavelength digital phase demodulation is realized and a new demodulation is currently under patent.