Piezoelectric copolymer jacketed single-mode fibers for electric-field sensor application

Characteristics of a piezoelectric copolymer jacketed optical fiber are presented. The jacket consisting of a copolymer of vinylidene fluoride and trifluoroethylene was made piezoactive by corona poling. The performance of the fiber as an optical-phase modulator was demonstrated over a frequency range of 20 Hz–5 kHz. An electric field-induced phase shift of 1.5×10−7 rad/(V/m) per meter of fiber was measured in the low-frequency (axially unconstrained) region. Several resonance peaks in optical phase shift were observed and discussed in conjunction with piezoelectricity in polymer jackets.