Fiber-optic voltage sensor based on a Bi12TiO20 crystal

A fiber-optic voltage sensor based on the longitudinal Pockels effect in a Bi(12)TiO(20) crystal is described. The use of a special backreflecting prism as a phase-retarding element is shown to improve the sensitivity and temperature stability of the sensor. A comparison between the temperature properties of the glass backreflecting prism and that of a quarter-wave plate is derived. The sensor demonstrates temperature stability of +/-1.5% from -20 degrees C to 60 degrees C and sensitivity of 0.145% per 1 V(rms) at 850 nm without the use of an additional temperature control channel.