Frequency Shifted Digital Holography for the Measurement of Vibration with Very Small Amplitudes

摘要

A method for measurements of nanometer-scale vibrations based on frequency shifted time average digital holographic interferometry employing the principle of the phase shifting technique is presented. This approach allows a reduction of noise and results in a higher sensitivity. The method has been applied to study the normalized vibration amplitude and the structure of vibration modes of piezoelectric transformers and actuators. In addition, quantitative information on the vibration amplitudes has been obtained in some cases.