A fiber optic voltage sensor operating at two widely separated wavelengths
(633 nm - probe radiation and 976 nm - control laser) with optically contro
lled sensitivity is presented. The modulation depth of the sensor is calcul
ated as a function of the probe-to-control laser power ratio, orientation a
ngle and thickness of a phase prate. We have demonstrated experimentally th
e continuous changes of sensitivity from 0.01 to 0 and back to 0.008% per V
-rms varying the control power from 0 to 55 muW. (C) 2001 Published by Else
vier Science B.V.