Vibrational distribution measurement of piezoelectric devices using laser speckle and image processing techniques

Fast visualization techniques for vibrational distribution in piezoelectric devices are described. The methods are based on the speckle interference on the device surface, and apply a two-dimensional correlation filter to speckle image data for the driven and resting phases of the devices. In spite of having a short measurement time, these methods produce very clear high-contrast vibrational-distribution images. The experimental results for quartz resonators with rough or polished surfaces demonstrate the applicability of the proposed method.