Experimental research of optical fiber current sensors based on loren magnetic force

A simple device based on the Lorentz force to measure the current optical fiber sensors is proposed. Using two copper carrying wires, the two carrying wires are parallel to the fixed insulated coil spring. Then, they are vertically fixed on two coppers, respectively. When the current input the wires, Loren magnetic force will exist between wires. The force causes deformation of the spring and lead to the displacement of the fiber's end faces change, so the spectra should be changed. The experimental device is used to measure the current at range of 1~5 A, the time response is about 0.1 s, and resolution sensitivity of this sensor is 10 nm/A. When the stiffness coefficient of the spring is K=0.1 N/m, the sensor can measure the range of 155 A. The results show that the device is simple and low cost, it has a potential application in high current sensing. ©, 2014, Guangxue Xuebao/Acta Optica Sinica. All right reserved.