Category: Metrology

The Smartt interferometer or its evolution, the Phase-shifting point diffraction interferometer is probably the most accurate one can make, and it is not even expensive. It has its limitation, doesn’t everything, such as that we need a focus to create a reference wave with a pinhole. If the focus is at a high numerical aperture,…

Optical wavefront measurement, or wavefront metrology, is a big subject. In this tech talk, we will focus on two topics which could even be considered dichotomies, phase-shifting interferometry and Shack-Hartmann wavefront sensing. With phase-shifting interferometry, accuracy is key and every nanometer is significant. Speed and versatility come second. Quite the opposite can be said for…