A Compact FBG-Based Magnetostrictive Optical Current Sensor With Reduced Mass of Terfenol-D

In this letter, we performed finite element method (FEM) simulations, fabrication, and experimental characterization of two prototypes of fiber-optic current sensors (FOCS) based on fiber Bragg grating (FBG) and Terfenol-D for monitoring current in high-voltage transmission lines. The proposed prototypes were designed in geometrical configurations that allowed a massive reduction of more than 98% in the amount of Terfenol-D employed compared to FBG-based FOCS proposed previously. Using only 5.6 and 2.0 g of Terfenol-D in each prototype, we show that not only the cost of the sensor can be reduced but also greater sensitivity, linearity, and fast response-time to transient events were achieved.