关键词:传感器;光纤传感器
摘 要:An electric current sensor based on Faraday rotation effect in optical fiber was developedfor measuring aircraft lightning current. Compared to traditional sensors, the design hasmany advantages including the ability to measure total current and to conform to structuregeometries. The sensor is also small, light weight, non-conducting, safe from interference,and free of hysteresis and saturation. Potential applications include characterization oflightning current waveforms, parameters and paths, and providing environmental data foraircraft certifications. In an optical fiber as the sensing medium, light polarization rotateswhen exposed to a magnetic field in the direction of light propagation. By forming closedfiber loops around a conductor and applying Ampere’s law, measuring the total lightrotation yields the enclosed current. A reflective polarimetric scheme is used, wherepolarization change is measured after the polarized light travels round-trip through the sensing fiber. The sensor system was evaluated measuring rocket-triggered lightning overthe 2011 summer. Early results compared very well against a reference current shuntresistor, demonstrating the sensor’s accuracy and feasibility in a lightning environment.While later comparisons show gradually increasing amplitude deviations for anundetermined cause, the overall waveforms still compared very well.