Optical behavior simulation of the divergence adapter elements in a Ronchi deflectometry configuration for convex surfaces
F. Gonzales, J. Arasa
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Base Information
Volume
V55 - N3 / 2022 Ordinario
Reference
51107
DOI
http://dx.doi.org/10.7149/OPA.55.3.51107
Language
English
Keywords
Ronchi deflectometry, convex surfaces, divergence adapter, simulation, metrology.
Abstract
The primary purpose of this article is to show the simulation of the optical behavior of the divergence adapter elements in the Ronchi deflectometry configuration to measure convex surfaces, which so far has not been reported in the literature. The use of divergence adapter elements is mandatory when Ronchi deflectometry is used to obtain the shape of a convex surface. Otherwise, light reflected by the surface cannot be collected into the measuring stage. Divergence adapters must be included in both arms of the Ronchi deflectometry configuration, keeping in mind that their optical behaviors affect the surface shape measurement. Before carrying out an experimental setup, we analyzed these elements' effects through an optical simulation of the selected Ronchi. From the analysis of the optical simulation, we can check the adequacy of the divergence adapter for the expected measuring range and required accuracy; the decision about its suitability has been taken by looking if the relations between slope and position at the apex of the convex surface was unequivocal. In this paper, we present the Ronchi configuration chosen to measure convex surfaces, the selected lenses for the divergence adapters, the thresholds linked to the sampler’s elements, the optical simulation, and the criteria used to answer if the behavior of the divergence adapters is appropriated for the radii interval that we want to measure. Finally, a unique polynomial expression is proposed to transfer slope and position values from the sampling elements of the apex plane of the surface to be measured.