Concave reflective surfaces topographic inspection using robust non-contact techniques

A robust non-contact technique for performing topographic measurements on reflective concave surfaces is presented, allowing the measurement of submicrometric features of the surfaces under test. The advantages of a non-contact optical technique are combined with a robustness to environmental alterations (no vibration isolated mounts, tolerance to the positioning of the sample) which makes it an optical inspection technique specially fit for inclusion in automated industrial outlines. Results are provided for surfaces of polished ophthalmic lenses, showing the ability of the technique to be applied in precision quality control tasks of any reflective concave surface.