Fiber optic sensor for simultaneous measurement of voltage and temperature

We report a new configuration of the fiber optic voltage sensor based on the Bi 12 TiO 20 crystal, which allows simultaneous measurements of both voltage and temperature. In our scheme, a quarter-wave plate, being an inherent element of voltage sensor, serves simultaneously as a phase-shifting element and as a temperature sensitive element. The sensor operates at two wavelengths (633 nm and 976 nm). The sensor has a linear temperature characteristic within the range of 10divided by70 degree(s)h, providing the accuracy of temperature measurements of 0.3 degree(s)h. As a voltage sensor, this device has a linear amplitude characteristic up to 1000 V rms and the excellent temperature stability of 0.1 % within the temperature range of 10divided by70 degree(s)h.