Optical form measurement employing a tiltable line scanning, low coherence interferometer for annular subaperture stitching interferometry

This contribution presents experimental and simulation results of a tiltable line scanning low coherence interferometer applied for form measurement of spherical and aspherical objects with a diameter of up to 300 mm. The region of interest is sampled by multiple annular subapertures that are realigned employing stitching algorithms based on Cartesian- and Zernike polynomial fittings. The paper addresses common challenges in the reduction and modeling of displacement errors associated with the motion of the interferometric sensor between subaperture measurements and compares the topography deviations of the experimental results with those simulated by a Monte Carlo based model.