Research On Reflected Intensity Modulated Optical Fiber Distance Sensor Based On Plastic Optical Fiber

With the rapid development of optical fiber manufacturing and a variety of in-depth studyof the optical fiber material, the optical fiber sensing technology has the rapid development ofits unique advantages. Reflective Intensity Modulated Fiber Optic Displacement Sensor(RIM-FODS) is widely used in distance, pressure, vibration, sound and other physicalmeasurements because of it advantages including simple principle, higher bandwidth, flexibledesign, make convenient, stable performance, et al. Compared to traditional quartz fiber,plastic optical fiber has low-cost, large numerical aperture and toughness advantages, it has abroad application prospects in the field of fiber optic sensing. Papers do research on PlasticFiber-Optic Displacement Sensor.First of all, a theoretical model for the intensity modulation model of the plastic opticalfiber RIM-FODS was established using the quasi-Gaussian distribution to describe plasticoptical fiber outgoing light field. Numerical simulations are made to study the influence ofCharacteristic parameters function of the sensor intensity modulation function. Simulationanalysis also made to study Light intensity modulation characteristics based on the fiberbundle sensor. Designed the RIM-FODS overall plan and selected the appropriate light sourceand detector.Second, design the RIM-FODS photoelectric signal processing systems based on weakoptical signal processing theory. The design takes advantage of coss-correlation detectiontheory and lock-in amplification technology principle, and then Design circuit. The signalprocessing circuit part includes a light source modulation and the driver module, aphotoelectric conversion module, the pre-amplification module, band-pass filtering module,the phase-sensitive detector module, and a low pass filter module.Third, design and implement the RIM-FODS data acquisition system. The dataacquisition system mainly including AD conversion module, USB data transmission module,FPGA control module and the host computer module. The software includinganalog-to-digital converter, USB data transmission control procedures and the combinationof both based on FPGA was designed.Finally, the paper builds the optical experiment platform to text the theory results. including the intensity-modulated characteristics test, system repeatability and stability, andsensitivities of RIM-FODS, et al. The experiment’s effect is good, meets the designexpectations basically.