Optical spherometer for measuring large curvature radii of convex surfaces

摘要

Measuring large curvature radii of convex surfaces with high precision is a challenge because the spherometer's focus must be positioned at the apex of the surface and at the center of curvature of the surface by moving the surface or the spherometer. If the radius of curvature is larger than the back focus of spherometer, then measurement is not possible. In this work, we propose to use the FOCOIVA system to move the focus of the spherometer in longitudinal way without modifying the f number by moving two lenses inside it, with this mechanism it is possible to measure radii of curvature of several meters in length. The curves of movement of the lenses and the optical parameters of the lenses that compose the spherometer are presented.