Multi-point dynamic displacement probe that uses a self-focusing micro-lens array

A multi-point dynamic displacement probe was developed for measuring dynamic displacement and deformation. In this probe, a self-focusing micro-lens array (SMLA) replaces a microscope objective normally used in autofocus sensors, and an acousto-optic deflector (AOD) is used as a scanner to allow the collimated laser beam to scan the SMLA, namely, allow the focused spot to scan the sample surface. Due to the very high scanning speed of the AOD, the relative position of many points, and thus the dynamic deformation, can be measured in near real time. The method's principles, accuracy, and error sources are described. (C) 1997 Society of Photo-Optical Instrumentation Engineers.