Positioning sensing with a Shack-Hartmann wavefront sensor

Summary form only. The Shack-Hartmann wavefront sensor is becoming nowadays a popular optical laboratory tool. Its inherent mechanical properties and conceptual simplicity and the possibility of working even with non monochromatic light sources, are its main advantages in the field of wavefront sensors. In this work we introduce the use of a Shack-Hartmann (SH) sensor as a positioning device. As the lateral shearing interferometer the Shack-Hartmann sensor can achieve a multiple range superresolution compared to the Rayleigh depth of focus. It belongs to a class of optical devices which estimate the shape of an incoming wavefront from a set of measurements of its local slopes.