An electric-field sensitive fiber with coaxial electrodes for optical phase modulation

It was shown that an electric-field sensitive optical fiber utilizing a radially poled piezoactive copolymer jacket is suitable for application as an all-fiber optical phase modulator. The jacket used was a copolymer of vinylidene fluoride and trifluoroethylene (P(VDF73/TrFE27)), 63-μm thickness, and was made radially piezoactive by corona discharge poling. The optical response of induced phase shift due to applied dc voltages was measured to be between0.80 × 10⁻⁵and1.24 × 10⁻⁵rad/(V/m) per meter of fiber. The performance of the jacketed fibers with coaxial electrodes as an optical phase modulator was tested over a wide frequency of range, from 20 Hz to 20 KHz.