Ronchi and Moiré patterns for testing spherical and aspherical surfaces using deflectometry

Abstract

The aim of this paper is to compare the Ronchi test and the Moiré deflectometry applied to a new pattern. To do so, we used two Ronchi patterns (typical Ronchigrams) produced by two identical Ronchi rulings angularly displaced and placed close to the curvature radius of a mirror. The result obtained by superposing both Ronchigrams is our new pattern, a Moiré pattern of the Ronchigram (Moiré-Ronchigram). The Zernike aberration polynomial coefficients of the tridimensional wavefront for both mirrors are obtained as a result. We also compared the Zernike coefficients obtained for each of the mentioned techniques and we found that the results with less dispersion are those where Moiré deflectometry was applied. Finally, as a confidence test for applying and testing the Moiré-Ronchigram, we compare our results with Open Fringe, FringeXP, and APEX, using the root-mean-square and standard deviation values.