The inability of an optical spherometer to measure large curvature radii in optical convex surfaces is well known. This is because the movement of the optical component or the instrument cannot be physically carried out since this would involve crossing each other. This study proposes the opto-mechanical design of a spherometer that will have a source light, a beam splitter, and a liquid lens composed of a plane surface and a transparent elastic membrane with a liquid medium between them. By changing the volume of the liquid the shape of the membrane and the thickness of the lens will change. The present study offers a paraxial analysis of the relationships obtained to measure the curvature radius together with its uncertainty as a function of changes in the volume. The study also presents the work range of the instrument. The instrument is focused on the vertex of the surface and on the center of curvature with aid an intensity detector.

Date Published: 2 October 2007
PDF: 8 pages
Proc. SPIE 6665, New Developments in Optomechanics, 666510 (2 October 2007); doi: 10.1117/12.734477

Published in SPIE Proceedings Vol. 6665:
New Developments in Optomechanics
Alson E. Hatheway, Editor(s)