Sobre métodos ópticos para la reconstrucción del frente de onda: novedades, mejoras y modificaciones en los métodos para aplicaciones en la industria aeroespacial
Different optical methods for phase recovering and therefore the wavefront are related with a set of direct techniques as interferometry, indirect ones like Shack-Hartmann sensing and iterative methods where an objective function is optimized. The aerospace industry has used techniques coming from o...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | español |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/26782 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/26782 |
| Access Level: | acceso abierto |
| Palabra clave: | 629.7(043.2) Aeronautica Aeronautics Aeronáutica 3301 Ingeniería y Tecnología Aeronáuticas |
| Sumario: | Different optical methods for phase recovering and therefore the wavefront are related with a set of direct techniques as interferometry, indirect ones like Shack-Hartmann sensing and iterative methods where an objective function is optimized. The aerospace industry has used techniques coming from optical metrology for the assembly and integration of instruments with optical properties. However, also other subjects use, involve and push the development of these kind of techniques, for example in microscopy. Currently, the wavefront retrieval techniques have been improved and strengthened by using algorithms coming from computer graphics. In addition, the design of filters and phase demodulation by using the theory of signals coming from electronic engineering and telecommunications. In addition to the improvements in algorithms, the experimental optical methods have triggered innovative developments considering the emergent technologies based on liquid crystal (spatial light modulators - SLMs) and its ability to modulate phase, amplitude or both easily. Furthermore, the performance in terms of response times, resolution and modulation capabilities, among others, of liquid crystal devices are improving constantly. This thesis proposes new methods and improvements in techniques for recovering the wavefront in order to be used in the corresponding processes of assembly and integration of optical instruments for space. A method able to recover the phase with abrupt differences of intensity in the incoming field is proposed from the conventional interferometry by using techniques coming from computer graphics and fringe normalization through filters described since the signal theory. A comparison between electronic speckle pattern interferometry (ESPI) and differential interferometry showing as a disadvantage that the last one does not recover the phase of an extended object. Moreover, the wavefront recovery in topographic applications is proposed in ESPI by using two wavelengths, and adapting the wavefront by using a SLM. In this way, it was proposed a complete new method, where the wavefront is modified by introducing an orbital angular momentum (OAM) using an experimental setup ESPI to overcome the sign ambiguities which are typical on interferometry since the experiment. There were proposed two new methods from the indirect methods focused on Shack-Hartmann sensing. The first one uses spiral phase filtering. This filter is an extension of the ESPI experimental setup introducing an optical vortex in the reference beam since the perspective of image processing. Moreover, it is a generalization of the high dynamic range (HDR) method proposed in the experimental setup of conventional interferometry. The second one, is a novel proposal to recover the wavefront in zonal mode, using the optical flow method coming from computer graphics and to avoid the computation for the centroids in a traditional way, which is computationally expensive. At last, a revision of the iterative methods for phase recovering and their usefulness on the integration of optical instruments is presented |
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