Mazine, Alexandre (2006) La caractérisation de front d'onde dans un système de propagation à multi-illumination gérée par un modulateur spatial de lumière. PhD thesis Signal et Images, Optique, ENST.
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Abstract
Phase retrieval is a cornerstone of wavefront analysis, which is finding ever wider applications in many fields where it is met under two forms: wavefront reconstruction and surface analysis. Present techniques leave opportunities for novel methods: more powerful, more efficient and especially cheaper. Whereas the most popular techniques require sophisticated optical equipement, the use of a diffractive solution makes possible the use of low cost equipment combined with a powerful intelligent digital image-processing. The aim of this study is, on the one hand, to demonstrate the feasibility of a multiview principle dealing with phase retrieval of an unknown beam and on the other, to design an experimental setup that is able to determine the phase map from a small number of captured diffraction patterns. We propose a method, called here ``multi-illumination'', for extracting this phase-information with the aid of a spatial light modulator which produces a range of different illuminating beams. This method involves a digital image-processing based on the Iterative Fourier/Fresnel Transform Algorithm (IFTA) principle. Two versions are developped: the first using images grabbed in a coherent imaging system, the second works with diffraction patterns obtained in a double Fresnel/Fourier setup. The capacities of the algorithm are verified both in extensive digital simulations and in an experimental setup built up with a SLM and a CCD syncronously managed by a specifically developped software.
Key-words: wavefront analysis, phase retrieval, spatial light modulator, multiview, iterative Fourier/Fresnel transform algorithms.
| Item Type: | PhD Thesis (PhD) |
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| Thesis Supervisor: | De Bougrenet de la Tocnaye, Jean-Louis |
| Date: | 2006 |
| Board of examiners: | Maruani, Alain and Ambs, Pierre and Keryer, Gilles and Heggarty, Kevin |
| Ecole Doctorale: | ED 130 INFORMATIQUE, TELECOMMUNICATIONS ET ELECTRONIQUE (EDITE) |
| Discipline: | Signal et Images |
| Collection (Fonds): | ENST |
| Institution: | ENST |
| Department: | Optique |
| Subjects: | 3. Physics, Optics |
| Uncontrolled Keywords: | Analyse de front d'onde, Reconstruction de phase, Slm, Algorithmes iteratifs |
| ID Code: | 1748 |
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| Deposited By: | Alexandre Mazine |
| Deposited On: | 22 May 2006 |
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