A polyvinylidene fluoride (PVF
2) phase shifter is characterized in terms of amplitude response linearity, frequency response uniformity, and ultimate sensitivity to electric field. Phase-drift compensation with this PVF
2device is demonstrated in a Mach-Zehnder fiber interferometer. The compensator can be operated at the

-phase mode for maximum sensitivity in detection applications, or the π-phase mode for maximum frequency mixing efficiency.