Analysis on a Novel Reflective Intensity Modulated Fiber Optic Temperature Sensor

摘要

Fiber optic temperature sensors are widely used in smart materials and structure health monitoring.In this paper,a novel reflective intensity modulated fiber optic temperature sensor(RIM-FOTS)is designed and analyzed.The mercury is filled into the hollow fiber and the surface of the mercury acts as the reflective mirror.The intensity of the reflective light is the function of the distance between the surface of the mercury and the fiber end,which is determined by the thermal extension of the mercury.And different length of the mercury in the capillary defines different sensitivity of the sensor.The modulation function of the RIM-FOTS is also analyzed.Experiment was carried out to evaluate the performance of the sensor.A number of RIM-FOTSs of different length of the mercury were made to test the variety of the sensitivity.The outer diameter of the sensor is less than 250 μm and the length of the sensor is less than 20 mm.Experiment shows the sensitivity of the RIM-FOTS is higher than 0.1°Cand a good correlation between the theoretical and experimental result is also presented by the experiment.