Piezoelectric/electrostrictive materials are a unique class of nonconducting, anisotropic materials which change in dimension due to the application of an electric field and thereby may be used as mechanical actuators. The most widely used actuation materials for acoustic transduction applications are piezoceramics, such as lead zirconate titanate (PZT) and lead magnesium niobate (PMN). Disadvantages of these materials include relatively high creep and hysteresis, the tendency of the ferroelectric dielectric material to retain electric potential after the alternating electric field to which it is subjected reverses polarity, thus causing electrostatic action to lag the applied voltage. The need to study the geometrical, material, and time dependent nonlinear behavior, as well as the interaction effects between sensors and actuators, is increasingly apparent, although a unified approach for modeling the local and global response of a nonlinear active material system has not been accomplished. In this paper we discuss the use of optical fiber-based short gage length Fabry-Perot sensors to experimentally verify an analytical model and allow determination of the nonlinear behavior of actuator elements without affecting their material properties.