Stitched Acousto-Optic Modulator Stroboscopic Interferometry for characterizing larger microstructures

Large field of view with higher resolution has become a strong requirement for the present measurement technology. Currently used sub-aperture stitching methods are suffering from the inaccuracies of computer controlled stages. In this work three different simplified stitching methods are presented. The stitching process proposed here is based on Acousto-Optic Modulator Stroboscopic Interferometry (AOMSI) of fixed field of view (FOV) and it does not require any computer controlled stage. A large microcantilever was tested in two stages, one from the root and the other from the tip portions separately, and the complete profile of the cantilever was extracted using the proposed stitching methods. The same cantilever also was tested using a commercial profilometer with a full field of view. There was a good agreement between the results from the proposed methods and a commercial profilometer. Obtaining extremely low amount of variation using the presented stitching methods validates the proposed stitching methods for large microstructures.