Numerical Analysis of Wavefront Approximation Accuracy by Means of Zernike Polynomials for Optical Surface Flatness Measurements Using a Hartmannometer Device

A metrological device—Hartmannometer—based on a Shack-Hartmann wavefront sensor for measuring the flatness of optical surfaces was developed and researched, and the results were compared with the results obtained from measurements using a Fizeau interferometer. The paper presents a method for calibrating a Hartmannometer, and also compares the results of measuring a test optical surface using the developed device and a classical Fizeau interferometer. The total amplitude of wavefront distortions measured using a Fizeau interferometer was 0.127 μm (standard deviation 0.022 μm). The Hartmannometer showed distortions amplitude of 0.131 µm (standard deviation 0.024 µm).