Evaluation of the increment of the sampling in optical testing using substructured Ronchi gratings

In this paper, we use Ronchi substructured gratings to evaluate the increment of the accuracy in optical testing using a liquid crystal display. For this, we perform a comparison between the aberration function and the wavefront obtained with classical Ronchi gratings against the ones obtained using substructured Ronchi gratings. This analysis is performed for different gratings positions, both outside and inside of focus. We show the results obtained in the laboratory for a concave spherical mirror of 57.27 mm diameter and a radius of curvature of 397.55 mm. We conclude that by using substructured Ronchi gratings we can test a larger area of ronchigram.