The goal of this experiment is to demonstrate local differences in surface state on a diffusing object by double speckle photography. We record on a single holographic plate two images of the diffusing object lit with coherent light; between the two exposures we slightly modify the angle of incidence of the light beam. We then use the interference fringes produced in the Fourier plane of this double photograph; their visibility characterizes the correlation between the two speckle figures, related to the local surface state. By an appropriate filtering setup it is then possible to visually localize on the image zones of different rugosity.

Date Published: 18 April 1978
PDF: 4 pages
Proc. SPIE 0136, 1st European Conf on Optics Applied to Metrology, (18 April 1978); doi: 10.1117/12.956173

Published in SPIE Proceedings Vol. 0136:
1st European Conf on Optics Applied to Metrology
Michel H. Grosmann; Patrick Meyrueis, Editor(s)