An optical self-calibrating technique for the dynamic characterization of PZT's

A system suitable for the measurement of linear sinusoidal vibration amplitudes is described. The signal beam of a Michelson interferometer is focused on the vibrating target while a suitable phase noise is applied to the reference arm of the interferometer. Signal processing is based on the null adjustment of the Bessel coefficients J/sub 1/ and J/sub 2/ derived from the signal provided by a single photodiode placed in the center fringe of the interference pattern. The system has been shown to be self-calibrating and intrinsically immune to mechanical perturbations induced in the interferometer. The technique proposed has been experimentally demonstrated by measuring the vibration amplitude of a PZT device in the amplitude range from 0.4 to 1.7 mu m and in the frequency range from 8 to 22 kHz.<
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