A model in geometric optics, along with some preliminary experimental results for a new range-finding method that exploits near-field diffraction phenomena found with plane gratings, is presented. Among the characteristics investigated is a magnification effect applicable to three-dimensional microscopy. A variety of embodiments of the method is disclosed, including an off-axis illumination model and a method of near-field focus compensation that takes advantage of the Scheimpflug condition.
DeWitt, Thomas D. and Lyon, Douglas A., "Range-finding method using diffraction gratings" (1995). Engineering Faculty Publications. 87.
DeWitt, Thomas D., and Douglas A. Lyon. "Range-finding method using diffraction gratings." Applied optics 34, no. 14 (1995): 2510-2521.