Nanometric position and displacement measurement of the six degrees of freedom by means of a patterned surface element.
A method is presented for position and displacement measurements of the six degrees of freedom by use of a patterned surface element observed by a static interferometric vision system. The surface element is made of a regular pattern of circular holes etched on a chromium layer deposited onto a flat glass plate. The in-plane coordinates (x, y, theta(z)) are reconstructed with a subpixel resolution by a vision method based on phase measurements. The out-of-plane coordinates (z, theta(x), theta(y)) are reconstructed by phase-shifting interferometry. Resolutions achieved by the proposed method are in the range of microradians for the measurement of angles and of nanometers for the position and displacement.
Sandoz
Patrick
P
Département d'Optique P.M. Duffieux Institut Franche-Comté Electronique, Mécanique, Thermique et Optique-Sciences et Technologies, Universite de Franche-Comté, F25030 Besançon Cedex, France. patrick.sandoz@univ-fcomte.fr