Optical-fiber copolymer-film electric-field sensor

Characteristics of a fiber-optic sensor for the detection of external electric fields are presented. This device utilizes a single-mode fiber that is embedded in a poled vinylidene fluoride-tetrafluoroethylene copolymer film and incorporated as the sensor arm of a Mach-Zehnder interferometer. A low-frequency intrinsic sensitivity of (0.20 +/- 0.03) x 10(-12) m/V is measured which compares well with our projected theoretical static sensitivity. This sensitivity implies a minimum detectable field of 33 microAV/m for a 1.0-km length of activated fiber and a 10(-7)-rad phase-shift detection capability.