L’ELT (Extremely Large Telescope), est un télescope de diamètre 39 m en cours de réalisation par l’Observatoire Européen Austral (ESO). Pour pouvoir tirer pleinement parti de sa taille, ses instruments seront équipés de systèmes d’Optique Adaptative (OA) qui compenseront la turbulence atmosphérique. Ces systèmes d’OA requièrent l’utilisation d’étoiles guides laser afin de maximiser la couverture du ciel. Les étoiles guides laser sont générées par laser accordé sur une résonance d’atome de sodium présents dans une couche d’une épaisseur de 10 km et située à environ 90 km d’altitude. Une étoile laser est donc un cylindre lumineux dans la haute atmosphère, allumé par la relaxation des atomes. L’analyse de front d’onde à l’aide de ces étoiles artificielles souffrent de limitations connues. De plus, sur un télescope de la taille de l’ELT, leur utilisation est compliquée par l’effet de perspective qui provoque un allongement de l’étoile guide lorsqu’elle est vue d’un point éloigné de son point de lancement au sol : le cylindre n’est plus vu par une section circulaire, mais sur le côté. Sur un télescope de 39m, l’élongation de l’étoile peut alors atteindre jusqu’à 20 secondes d’arc, à comparer avec le diamètre du cylindre qui est déterminé par la turbulence, soit de l’ordre d’une seconde d’arc. La variabilité de l’épaisseur, de l’altitude et de la distribution de densité de la couche de sodium ont alors un impact sur la mesure du front d’onde.L’étude de ce problème, qui porte à la fois sur les algorithmes de mesure et le design des analyseurs de front d’onde, a donné lieu à de nombreux travaux s’appuyant sur des simulations et des tests en laboratoire. Le but de cette thèse a été d’étudier cette question à l’aide de données expérimentales obtenues sur le ciel. Ces données ont été enregistrées grâce au démonstrateur d’OA CANARY, situé sur le télescope William Herschel sur l’île de la Palma aux Canaries. CANARY a été développé par le LESIA, en collaboration avec l’Université de Durham; le laser et son télescope d’émission ont été fournis et opéré par l’ESO. Lors de cette expérience, l'allongement extrême des étoiles laser qui sera observé sur l'ELT a été reproduit en plaçant le télescope d’émission à environ 40m du télescope William Herschel. Le front d'onde a ensuite été mesuré sur l’étoile laser allongée ainsi crée.Les travaux effectués pendant cette thèse ont consisté en la préparation de l’instrument et en particulier de l’analyseur de front d’onde de l’étoile laser, la réalisation des observations et le traitement des données résultant de ces dernières. L’analyse de ces données a permis de construire un budget d’erreur de la mesure de front d’onde sur étoile laser allongée. Grâce à ce budget d’erreur, les performances de différents algorithmes de mesure ont été comparées, ainsi que leur comportement face à la variabilité du profil de sodium et des conditions de turbulence. Enfin, différentes configurations d’analyseurs ont été extrapolées, ce qui a permis d’établir des limites sur leur design dans le cadre de l’ELT. / The ELT (Extremely Large Telescope) is a telescope whose diameter is 39 m currently under construction by the European Southern Observatory (ESO). In order to fully benefit from its size, ELT instruments will be equipped with Adaptive Optics (AO) systems to compensate the atmospheric turbulence. These AO systems require the use of Laser Guides Stars (LGS) in order to have as large a sky coverage as possible. LGS are generated using a laser tuned on a resonant frequency of sodium atoms contained in a layer approximately 90km high and 10 km thick. Therefore, a LGS is a luminous cylinder in the high atmosphere, lighted by sodium atoms relaxation. Wavefront sensing on these artificial stars suffers from known limitations. On a telescope the size of the ELT, their use is further complicated by the perspective effect which causes an elongation of the LGS when it is seen from a point distant from its launch position : the cylinder is no longer seen by its circular section, but on the side. On a 39m telescope, the elongation can reach up to 20 arcseconds, which is large compared to to the diameter of the cylinder determined by the turbulence, that is about 1 arcsecond. Variability of the thickness, height and density distribution of the sodium layer then have an impact on wavefront sensing. The study of this problem, which concerns both sensing algorithms and wavefront sensor design, has already been the subject of many work relying on simulations and laboratory experiments. This thesis aims at studying this question using experimental data obtained on sky. These data were acquired using the AO demonstrator CANARY, placed on the William Herschel Telescope (WHT) on the island of La Palma in the Canaries Island. CANARY was developed by LESIA in collaboration with Durham University; the laser and its launch telescope were supplied and operated by ESO. In this experiment, the extreme elongation of LGS as will be seen on the ELT was reproduced by placing the launch telescope 40 m away from the William Herschel Telescope. The wavefront was the measured on the elongated LGS thus created. The studies led during this thesis consisted in the preparation of the instrument and in particular the LGS Wavefront Sensor (WFS), the realisation of the observations and processing on the data obtained. Analysis of these data allowed to build an error breakdown of wavefront sensing on the elongated LGS. Thanks to this error breakdown, performances of different measurement algorithms where compared, as well as their behaviour according to the variability of the sodium profile and the turbulence conditions. Finally, different wavefront sensor designs were extrapolated which allowed to establish limits on their designs for the ELT.

The main aim of this thesis is to evaluate the effect of meridional blur, using refractive induced astigmatism, on visual performance at far and close distances. Visual performance was evaluated using letter discrimination tasks at distance and near (visual acuity, VA) and a reading task at near on subjects with pharmacologically blocked (young) or absent accommodation (presbyopic and pseudophakic). The effect of astigmatism was tested using positive cylindrical lenses oriented at 180 and 90 degrees, these simulating with- (WTR) and against-the-rule (ATR) astigmatism. Other refractive status were also evaluated, namely, in-focus and spherical defocus. The visual performance data were correlated with biometric measurements (pupil size, anterior chamber depth (ACD), corneal and ocular aberrations, corneal multifocality, patient age, axial length). Further, the functionality of meridional blur was evaluated for alphabets in addition to the standard Roman alphabet using a VA task. The results confirm that myopic astigmatism contributes to a better visual performance at closer distances, with ATR astigmatism providing higher performance for reading tasks compared to other forms of astigmatism. Anatomical factors such as pupil size, corneal multifocality and ACD were significantly correlated visual performance, while other ocular characteristics were not. Ray tracing modelling using wavefront data was a moderate predictor of VA and reading acuity. The results of the effect of meridional blur orientation on alphabets other than the Roman alphabet, suggest that visual performance is dependent on the interaction between blur orientation and letter's spatial characteristics. In conclusion, pseudoaccommodation is a multifactorial phenomenon with pupil size being the major contributor for the improvement in visual performance. Against-the-rule shows advantages over WTR astigmatism, by providing higher reading performance, however extending the present and previous findings for clinical application will require further investigation on the effect of meridional blur in common and socio-culturally adapted tasks.

The thesis details the design and characterization of an innovative optical tweezer system. Optical tweezers provide a relatively new technique for non-contact manipulation of micron-scale particles. They employ a laser beam to hold such particles at the laser’s focus. Optical tweezers are used for many scientific purposes, such as: measuring the mechanical properties of bio-molecules, cell and molecule sorting, stiction-less micro-manipulators, and fundamental research in physics. Typically, trap location has been controlled using steer-mirrors or spatial light modulators, operating without beam quality feedback. Here, an innovative trap control system has been developed, featuring a closed-loop adaptive optics system. The prototype system employs a deformable mirror and wavefront sensor to control trap position in three dimensions, while simultaneously removing beam aberrations. The performance of this system is investigated in terms of controllable range of trap motion, trap stiffness, and trap position stability.

OBJETIVO: Comparar os resultados de duas técnicas cirúrgicas guiadas pela análise de frente de onda, a ceratectomia fotorrefrativa (PRK) e a ceratomileusis in situ a laser (LASIK), para correção da miopia baixa a moderada, associada ou não ao astigmatismo. LOCAL: Setor de Cirurgia Refrativa da Clínica Oftalmológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brasil. MÉTODOS: Estudo prospectivo randomizado envolvendo 70 olhos (35 pacientes) submetidos ao LASIK personalizado em um olho e PRK personalizado no olho contralateral para correção de miopia até 5 dioptrias (D) e astigmatismo até 1,5D. Avaliou-se acuidade visual não-corrigida (AVNC), melhor acuidade visual corrigida (MAVC), resultados refratométricos, aberrometria, sensibilidade ao contraste fotópico e mesópico, acuidade visual de baixo contraste (AVBC), qualidade da imagem retiniana (Função de Transferência Modular e Strehl ratio) e espalhamento intraocular de luz (EIL) no período pré-operatório e no 1o, 3o, 6o e 12o mês pós-operatório. RESULTADOS: O equivalente esférico (EE) médio pré-operatório foi -2,57 ± 0,95D no grupo LASIK e, no grupo PRK, -2,52 ± 0,90D (p = 0,722). No 12o mês pósoperatório (PO), EE foi -0,06 ± 0,33D e -0,12 ± 0,41D, respectivamente (p = 0,438). No grupo LASIK, 60,0% dos olhos apresentaram AVNC 20/16 e 96,7% 20/20, e no grupo PRK, 66,6% e 96,7%, respectivamente (p = 0,667). No período pré-operatório, o total das aberrações de alta ordem (HOAs) foi 0,37 ± 0,09 m no grupo LASIK e 0,36 ± 0,11m no grupo PRK (p = 0,752). No 12o mês PO, o total das HOAs foi 0,46 ± 0,21m no grupo LASIK e 0,42 ± 0,14m no grupo PRK (p = 0,438). Tanto o teste de sensibilidade ao contraste fotópico como o mesópico apresentaram resultados semelhantes entre as técnicas, exceto pela freqüência 1,5 ciclos por grau (cpg) do teste mesópico no 12o mês PO, a favor do grupo PRK. Os índices de qualidade da imagem retiniana mostraram comportamento similar entre as técnicas ao longo do seguimento. Não houve aumento significativo do espalhamento intraocular da luz em ambos os grupos, quatro olhos cursaram com aumento transitório. CONCLUSÃO: Dentro das condições deste estudo, ambas as técnicas apresentaram excelentes resultados refratométricos e função visual semelhante. Apesar do tratamento personalizado guiado pela análise de frentes de onda, houve indução das HOAs, de forma similar, tanto no LASIK como no PRK. / PURPOSE: To compare clinical results of two wavefront-guided treatments, photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK), for low to moderate myopia correction, with or without astigmatism. SETTING: Refractive Surgery Service, General Hospital, University Of São Paulo, São Paulo, Brazil. METHODS: Prospective randomized study of 70 eyes (35 patients) submitted to custom LASIK and custom PRK (contralateral eye) for myopia up to 5D and astigmatism up to 1,5D. Uncorrected visual acuity (AVNC), best-corrected visual acuity (MAVC), refractive results, wavefront analysis, photopic and mesopic contrast sensitivity, low contrast visual acuity (AVBC), retinal image quality (Modulation Transfer Function and Strehl ratio) and intraocular straylight (EIL) were performed preoperatively and at one, three, six and twelve months postoperatively. RESULTS: The mean preoperative spherical equivalent (EE) was -2,57 ± 0,95D in the LASIK group and -2,52 ± 0,90D in the PRK group (p = 0,722). At twelve months postoperatively (PO), the mean EE was -0,06 ± 0,33D and -0,12 ± 0,41D, respectively (p = 0,438). In the LASIK group, 60,0% had AVNC 20/16 and 96,7% 20/20, and in the PRK group, 66,6% e 96,7%, respectively (p = 0,667). The mean pre-treatment total high-order aberrations (HOAs) was 0,37 ± 0,09 m in the LASIK group and 0,36 ± 0,11m in the PRK group (p = 0,752). At twelve months PO, the mean total HOAs was 0,46 ± 0,21m in the LASIK group and 0,42 ± 0,14 m in the PRK group (p = 0,438). No significant difference in photopic and mesopic contrast sensitivity between groups was noted, apart from the 1,5 cpg frequency of the mesopic test, favoring PRK, at the 12th month PO. Similar results were found for retinal image quality metrics during the follow-up. No significant increase of the intraocular straylight was found for both techniques, four eyes presented transitory elevations. CONCLUSION: In the conditions of this study, both techniques had excellent refractive results and similar visual function. In spite of the wavefront-guided treatments, HOAs were induced similarly after LASIK and PRK

Les signaux non linéaires provenant de nanostructures métalliques et cristallines sont connus pour être fortement dépendants vis à vis de la polarisation. Ceci est dû à leur propriété de symétrie locale, reliée à leur réponse volumique ou surfacique. Les signaux de polarisation venant de nanostructures de taille inférieure à la limite de diffraction sont généralement mesurés avec un spot limité par la diffraction (300 nm) ce qui représente la moyenne du signal. Cette technique a pour défaut de perdre l'information spatiale du signal de polarisation. Nous avons développé une nouvelle méthode de microscopie à polarisation non-linéaire qui exploite l'information en dessous de la limite de diffraction.Une analyse de Fourier d'un signal non linéaire a été faite en dessous de la limite de diffraction sur une image sur-échantillonnée et corrigée (taille du pixel=50 nm). Le gain en résolution est du à la sensibilité spatiale de la polarisation. Pour ce faire, nous avons mesuré un signal polarisé de seconde harmonique de nanostructures plasmoniques de différentes formes (150 nm). Nous avons montré que la nature vectorielle du champs local confiné peut être retrouvé avec une résolution de 40 nm en utilisant la nanoscopie polarisée non linéaire. Nous avons par ailleurs montré que nous pouvons imager l'hétérogénéité spatiale de nanoparticules ferroélétriques cristallines (BaTiO3) de taille allant de 100 nm à 500 nm. Ceci prouve l'existence d'une coque centrosymétrique dans des petites structures. Enfin, les nanocristaux de KTP nanostructures sont les candidats idéaux pour la générations de signaux non linéaires bien maîtrisée. / In this work, we develop a novel polarized nonlinear microscopy method that exploits sub-diffraction resolution information. Fourier analysis of the polarization modulated nonlinear signal is performed on over-sampled, drift-corrected images (50nm pixel size). The information gained by polarization-induced modulation signals provides a higher level of spatial selectivity that is directly related to the local optical response of the investigated system, at a scale below the diffraction limit. The gain in spatial scale is due to the additional spatial sensitivity brought by polarization. This approach is applied to polarized second harmonic generation imaging in plasmonic nanostructures (150nm size) of multi-branched shapes, in which the vectorial nature of the local field confinement can be retrieved with a resolution of 40 nm. We also demonstrate the possibility to image spatial heterogeneities within crystalline ferroelectric BaTiO3 nanoparticles of 70nm to 500nm size, emphasizing in particular the existence of a centrosymmetric shell in small size structures. These nanostructures will be used as starting models for coherent optical probes in biological media (cells, tissue slices or in vivo) with two objectives. First, the nonlinear nature of their emission will make them stable and tunable nanosources, able to report their localization with high accuracy in 3D, potentially sensing local environment changes, and actively inducing perturbations such as controlled temperature increase at the nanoscale. Second, the coherent nature of their emission will make them useful as local nanoprobes for wavefront and polarization correction through scattering media.

One of the highest resolution astronomical images ever taken in the visible were obtained by combining the techniques of adaptive optics and lucky imaging. The Adaptive Optics Lucky Imager (AOLI), being developed at Cambridge as part of a European collaboration, combines these two techniques in a dedicated instrument for the first time. The instrument is designed initially for use on the 4.2m William Herschel Telescope (WHT) on the Canary Island of La Palma. This thesis describes the development of AOLI, in particular the adaptive optics system and a new type of wavefront sensor, the non-linear curvature wavefront sensor (nlCWFS), being used within the instrument. The development of the nlCWFS has been the focus of my work, bringing the technique from a theoretical concept to physical realisation at the WHT in September 2013. The non-linear curvature wavefront sensor is based on the technique employed in the conventional curvature wavefront sensor where two image planes are located equidistant either side of a pupil plane. Two pairs of images are employed in the nlCWFS providing increased sensitivity to both high- and low- order wavefront distortions. This sensitivity is the reason the nlCWFS was selected for use with AOLI as it will provide significant sky-coverage using natural guide stars alone, mitigating the need for laser guide stars. This thesis is structured into three main sections; the first introduces the non-linear curvature wavefront sensor, the relevant background and a discussion of simulations undertaken to investigate intrinsic effects. The iterative reconstruction algorithm required for wavefront reconstruction is also introduced. The second section discusses the practical implementation of the nlCWFS using two demonstration systems as the precursor to the optical design used at the WHT and includes details of subsequent design changes. The final section discusses data from both the WHT and a laboratory setup developed at Cambridge following the observing run. The long-term goal for AOLI is to undertake science observations on the 10.4m Gran Telescopio Canarias, the world's largest optical telescope. The combination of AO and lucky imaging, when used on this telescope, will provide resolutions a factor of two higher than ever before achieved at visible wavelengths. This offers the opportunity to probe the Cosmos in unprecedented detail and has the potential to significantly advance our understanding of the Universe.

Cette thèse étudie le façonnage de champs électromagnétiques micro-ondes dans des cavités présentant des conditions aux limites reconfigurables. Le dispositif expérimental s'appuie sur une metasurface électroniquement reconfigurable qui couvre partialement les parois d'une cavité et qui permet ainsi de contrôler la façon dont les ondes y sont réfléchies. Le premier chapitre explore des aspects fondamentaux. D’abord, une étude paramétrique du façonnage d'un champ d'ondes électromagnétiques monochromatique et stationnaire en cavité est proposée en fonction d'un degré de contrôle introduit. Selon la valeur de ce paramètre, il est possible de concentrer de l'énergie en un endroit donné de la cavité de façon prédictible, de reconfigurer totalement cette cavité, ou bien de décider d'obtenir une résonance à une fréquence qui n'en supportait pas auparavant. Ensuite, l’imposition d’un comportement chaotique à une cavité de géométrie régulière est démontrée et une application au brassage des modes en chambre réverbérante est donnée. Dans la suite, la possibilité d’ajuster le couplage antenne-cavité est abordée, et une adaptation parfaite et dynamiquement configurable de l’impédance est proposée. Le reste du premier chapitre considère des champs transitoires. Dans un premier temps, la focalisation spatio-temporelle d’une impulsion fortement réverbérée dans une cavité en utilisant uniquement le contrôle spatial des ondes offert par la metasurface est démontrée, puis le lien avec le couplage entre les dégrées de liberté spatiaux et temporels du milieu de propagation est fait. Enfin, un dispositif permettant la reconfiguration répétée des conditions aux limites d'une cavité en un laps de temps inférieur au temps de vie des photons est réalisé, et des résultats préliminaires sont montrés. Dans le deuxième chapitre, des applications aux systèmes de communication sans fil multi-utilisateurs sont proposées. D’abord, dans la limite d’un bas facteur de qualité de la cavité, il est montré qu’un formalisme matriciel permet de décrire l’impact de la metasurface sur le champ. Cette matrice, mesurée sans information de phase, permet alors de focaliser le champ sur une ou plusieurs positions simultanément. Ensuite, la possibilité d’obtenir une diversité de canaux optimale (orthogonalité des canaux) en façonnant idéalement le désordre d’un milieu de propagation à l'aide de metasurfaces est établie. Finalement, le formalisme matriciel est utilisé afin d’introduire un concept de calcul analogique réalisé par le milieu désordonné en façonnant le front d’onde incident. Il est dès lors conclu qu’avec une infrastructure standard de Wi-Fi dans une maison, en combinaison avec une metasurface simple, cette idée peut être implémentée. Le concept est enfin transposé au domaine optique avec une fibre multimode. Au cours du troisième chapitre, quelques applications du façonnage d'ondes en milieux réverbérants aux capteurs des environnements connectés sont étudiées. D’abord, la possibilité de concentrer des champs électromagnétiques ambients sur des circuits redresseurs afin d’obtenir des tensions de sortie utiles est démontrée. De plus, grâce aux non-linéarités intrinsèques du redresseur, ceci est possible même sans avoir un retour direct du redresseur sur l’intensité du champ incident. Ensuite, un détecteur de mouvement hors ligne de vue et « intelligent » est proposé, qui profite d’un co-design de sa couche physique et du traitement de données. Enfin, il est démontré que même des objets non-coopératifs dans un environnement complexe peuvent être localisés grâce à leur contribution à la diffusion des ondes dans ledit milieu. L’équivalence d’utiliser la diversité fréquentielle ou bien le façonnage d’ondes dans ce contexte est établie. / In this thesis, the shaping of microwave fields in chaotic cavities with tunable boundary conditions is studied experimentally. The experiments leverage a metasurface reflect-array that partially covers the cavity walls to tune the reverberation of waves inside the cavity. The first chapter explores several fundamental aspects. First, the achievable degree of control over stationary monochromatic wave fields is thoroughly investigated, and various regimes are identified, ranging from partial control over the wave field up to the limiting case of discrete resonances that can be tuned at wish. Next, the possibility to convert a cavity of regular geometry into one displaying chaotic characteristics by modulating the boundary conditions is examined and an application to non-mechanical mode-stirring in reverberation chambers is given. Then, the ability to tune the coupling between an antenna inside a cavity and the cavity itself is studied, revealing the opportunity of achieving (dynamically tunable) perfect impedance matching. The chapter goes on to consider spatio-temporal wave fields, and the re-focusing of such transient fields at a desired instant with the purely spatial control of the metasurface is demonstrated; moreover, the interplay of spatial and temporal degrees of freedom is addressed. Finally, an experimental platform enabling the rapid modulation of cavity boundary conditions within the photon lifetime is presented. The second chapter considers applications to multi-user wireless communication systems. First, it is shown that a matrix formalism to capture the impact of the metasurface on the wave field can be formulated in the regime of low reverberation, and even without access to phase information focusing on a single as well as on multiple targets is demonstrated. Second, it is shown that the channel diversity, which dominates the achievable capacity of information transfer, can be optimized by tweaking the environment’s disorder; perfectly orthogonal channels are obtained without any software or hardware efforts on the transmit or receive side, and the benefits of the implied minimal cross-talk are illustrated for the scenario of wirelessly transmitting a full-color image. Third, the matrix formalism is leveraged to propose a scheme of analog computation that counter-intuitively uses a disordered instead of a carefully tailored propagation medium, by appropriately shaping the incident wave front. A proof-of-concept demonstration suggests that combining ubiquitous Wi-Fi hardware in an indoor environment with a simple metasurface is sufficient to implement the concept. Finally, the concept is also implemented in the optical domain using a multimode fiber. The third chapter outlines a few applications for sensors in context-aware environments. First, it is shown that by shaping ambient wave fields, they may be concentrated on harvesting devices to increase the output voltage available for sensor powering; moreover, the non-linear nature of the harvesting device enables to do so without direct feedback from the target, using indirect feedback from the second harmonic. Second, a smart around-the-corner motion detector for complex environments is presented, enjoying a co-design of hardware and processing software by using a dynamic metasurface aperture; the latter is essentially a small (but still electrically large) disordered cavity with tunable boundaries that leaks tunable random radiation patterns that couple differently to the environment’s modes. Third, it is shown that objects may be precisely localized in complex environments even if they are non-cooperative by establishing signatures of their location that leverage their scattering contribution; this is demonstrated both with a frequency diverse and a wavefront shaping scheme, and the equivalence of the respective degrees of freedom is established.

Polarization-dependence provides a unique handle for extending the dimensionality of optical microscopy, with particular benefits in nonlinear optical imaging. Polarization-dependent second order nonlinear optical processes such as second harmonic generation (SHG) provide rich qualitative and quantitative information on local molecular orientation distribution. By bridging Mueller and Jones tensor, a theoretical framework was introduced to experimentally extend the application of polarization-dependent SHG microscopy measurements toward in vivo imaging, in which partial polarization or depolarization of the beam can complicate polarization analysis. In addition, polarization wavefront shaping was demonstrated to enable a new quantitative phase contrast imaging strategy for thin transparent samples. The axially-offset differential interference contrast microscopy (ADIC) was achieved as a combination of classic Zernike phase contrast and Nomarski differential interference contrast (DIC) methods. The fundamentally unique manner of this strategy also inspired rapid volumetric analysis in time dimension that is accessible for most existing microscopy systems. Finally, the dimensionality of high speed twophoton fluorescence imaging was extended to the spectral domain by spatial/spectral multiplexing, enabling beam scanning two photon fluorescence microscopy with 17 frames per second rate and over 2000 effective spectral data points.<br>

Les défaut de la vision sont analysés et classés à partir des caractéristiques mathématiques du front d’onde de l’oeil considéré. Après avoir présenté la méthode actuelle basée sur la décomposition du front d’onde dans la base orthonormale de Zernike ainsi que certaines de ses limitations, on propose ici une nouvelle base de décomposition. Celle-ci repose sur l’utilisation del’espace des fronts d’onde polynomiaux de valuation supérieure ou égale à L + 1 (où L est un entier naturel) et permet de décomposer de manière unique un front d’onde polynomial en la somme d’un front d’onde polynomial de bas degré (inférieur ou égal à L) et un front d’onde polynomial de haute valuation (supérieure ou égal à L + 1). En choisissant L = 2, une nouvelle décomposition est obtenue, appelée D2V3, où le front d’onde polynomial de haut degré ne comporte pas de termes de degré radial inférieur ou égal à deux. Cette approche permet de dissocier parfaitement les aberrations optiques corrigibles ou non par le port de lunettes. Différents cas cliniques présentés dans la dernière section permettent de mettre en évidence l’intérêt de cette nouvelle base de décomposition. / The eye vision defaults are analyzed and classified by studyingthe corresponding eye wavefront. After presenting the orthogonal basis, called the Zernike basis, that is currently used for the medical diagnosis, a new decomposition basis is built. It is based on the use of the space of polynomials of valuation greater or equal to L+1 (for L a natural integer). It allows to uniquely decompose a polynomial wavefront into the sum of a polynomial of low degree (lesser or equal to L) and a polynomial of high valuation (greater or equal to L +1). By choosing L = 2, a new decomposition, called D2V3, is obtained where the polynomial wavefront of high degree does not include terms of radial degree lesser or equal to 2. In particular, it allows to quantify perfectly the aberrations that can be corrected by eyeglasses or not. Various clinical examples clearly show the interest of this new basis compared to a diagnosis based on the Zernike decomposition.

No description available.