Fiber-optic current and voltage sensors using a Bi12GeO20single crystal

By using Faraday and Pockels´ effects of a Bi12GeO20(BGO) single crystal, two kinds of fiber-optic sensors for electric current and voltage were tentatively fabricated. The optimum design of these sensors and their performances were investigated. It was verified that the BGO crystal is very available for either of the current and voltage sensors with regard to their sensitivity and stability. As for the experimental results, the minimum detectable magnetic field of 10^-2Oe and the temperature dependence within ±2 percent in the temperature range of -25 to 85°C was obtained for the current sensor, while for the voltage sensor the sensitivity of 10^-3V and the temperature dependence within ± 0.5 percent was in the same temperature range.