Obtaining the wavefront phase maps of free form surfaces: using the least squares algorithm

7th International Congress of Engineering Physics

物理学;工业技术

Villalobos-Mendoza, B.^1 ; Aguirre-Aguirre, D.^1 ; Granados-Agustín, F.^1 ; Cornejo-Rodríguez, A.^1

Instituto Nacional de Astrofisica, Óptica y Electrónica, Luis Enrique Erro No.1, Sta., María Tonantzintla, C.P., Puebla

72840, Mexico^1

关键词: Conventional algorithms;    Free-form surface;    Interferograms;    Least squares algorithm;    Phase-shifting;    Spatial light modulators;    Twyman-Green interferometers;    Wave-front phase;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/582/1/012033/pdf
DOI  :  10.1088/1742-6596/582/1/012033

学科分类：工业工程学

来源: IOP

【 摘 要 】

In this work is presented the validation of the least squares algorithm proposed by Morgan (1982) and Greivenkamp (1984), to obtain the wavefront phase maps of a free form surface. The validation was made by simulating the synthetic interferograms of a free form surface using a Bessel function, each interferogram was simulated with a phase-shifting of π/20. This algorithm is applied to the experimental interferograms that are obtained in a Twyman-Green interferometer where the phase shifting is achieved by using a SLM (Spatial Light Modulator) that is placed in one of its arms; the phase shifts are achieved by displaying all the gray levels from 0 to 255 in the SLM. The phase shifts that are performed in this experimental setup are lower than π/4, therefore the conventional algorithms cannot be applied.