Fiber optic interferometry for precision measurement of the voltage and frequency dependence of the displacement of piezoelectric tubes

Piezoelectric tube scanners used in scanning microscopy show nonlinear displacements with applied voltage. We have used an optical fiber based interferometer to make precision measurements of these nonlinearities. We have made the measurement of the sensitivity coefficient (displacement/voltage) for a wide range of different scanning voltage ranges and scanning rates, and find that the sensitivity coefficient has nonlinearities of order 4% as a function of the applied voltage. A 3% frequency dependence of the sensitivity coefficient is also measured. A phenomenological model is used to characterize the frequency dependence on the basis of a single relaxation time constant. (C) 2001 American Institute of Physics.