Temperature-compensated AC current sensor using tandem flat-topped fiber Bragg gratings

摘要

An intensity-demodulated AC current sensor system, which compensated the background temperature, was proposed and demonstrated. Temperature-compensated current detection is achieved by designing a novel sensor head which makes a pair of flat-topped FBGs (FT-FBGs) having differential current responses and the same temperature responses. As a result, optical intensity after the two tandem FT-FBGs varies monotonously with measured current and has no relation to the background temperature. The experimental results shows that the minimum ac current of 2.4 A is detected by the sensor and a linear relationship in the range of 0–426.0 A is obtained.