Three-dimensional imaging by sub-Nyquist sampling of white-light interferograms

Abstract
We demonstrate a simple way of increasing the data acquisition and processing speed in a scanning white- light interferometer for surface topography measurement. The method consists of undersampling interference data and processing the resultant sub-Nyquist interferograms in the frequency domain to create complete three- dimensional images. Experimental results on a 20-jrm step height standard show a measurement repeatability of 10 nm. ~~~~~~~~~~Source