Design and test of a small size fiber-optic electric field sensor

The measurement of lightning electro-magnetic field and its coupling effects inside structures is a challenging problem in the research of lightning protection. A small size free-field sensor with built-in fiber-optic transmission system is developed. The sensor is in the type of small dipole antenna, which uses its outside shielding layer as a pair of antennas. Design of the probing circuit and the tested results are introduced in this paper. Measurement results show that the dynamic range of the sensor is 0.05V-1V, the non-linear distortion is less than 0.0053, the minimum resolution is less than 0.05V/m.