A low-cost approach to thermal error compensation of fiber optic sensor in field programmable gate array (FPGA)

A scheme for controlling thermal sensitivity of Faraday effect in interferometric fiber optic current sensor (FOCS) is presented. Temperature sensor is placed on fiber optic sensing head. Thermal behavior of FOCS is monitored after testing in thermal chamber from -10°C to 60°C. Equations of temperature, temperature gradient, and scale factor correction are estimated in MATLAB and implemented in FPGA. System is again tested in thermal chamber with same thermal profile and compensation is verified. The embedded solution is a simpler, cost effective, and faster.