Fiber sensor for simultaneous measurement of voltage and temperature

We report a new configuration of the fiber-optic voltage sensor based on the Bi/sub 12/TiO/sub 20/ crystal, which allows simultaneous measurements of both voltage and temperature. In our scheme, a quarter-ware 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 and 976 nm). The sensor has a linear temperature characteristic within the range of 10/spl deg/C-70/spl deg/C, providing the accuracy of temperature measurements of 0.3/spl deg/C. As a voltage sensor, this device has a linear amplitude characteristic up to 1000 V/sub rms/ and the excellent temperature stability of 0.1% within the temperature range of 10/spl deg/C.-70/spl deg/C.