Proof-of-concept demonstration of smart optical imaging systems

This thesis focuses on the proof-of concept demonstration of smart optical imaging systems. Two systems have been investigated: first, a three-channel multi-resolution imaging system and in second place, a refocusing imaging system. The three-channel multi-resolution optical imaging system (Static System) has already been investigated by Ir. Gebirie. Y. Belay. The system possesses three optical channels with different resolutions and fields of view. The first channel has the highest resolution and the lowest field of view; the third optical channel has contrary properties, that is, the widest field of view and the lowest resolution. The second optical channel has intermediate properties. The experiments accomplished show that the system performs according to the expectations (simulations) and the quality of the images captured by the system is good. It has been observed two phenomena: distortion in the second optical channel and crosstalk in the third optical channel. The influence of misalignment errors of the components has been analyzed as well. The system is robust to longitudinal movements of the components, especially the first optical channel. Nevertheless, the system is less sensitive to rotational movements, becoming important the achievement of a good angular alignment. The refocusing system is a voltage-tunable refocusing optical imaging system. The voltage applied to an electrically tunable liquid lens allows obtaining a sharp image for a large range of object positions. This fact is an added value with respect to the Static System, where the object distances range is limited. The refocusing optical imaging system (Dynamic System) was designed by Lien Smeesters (et al.) and consists of two optical channels. The first channel is the third optical channel of the Static System and the second channel is the refocusing channel. This channel is compound of two passive lenses and the voltage-tunable liquid lens (Varioptic Arctic 320) in-between the two passive lenses. Each passive lens is composed of two aspheric surfaces (concave and convex). The lenses have been fabricated in PMMA by ultraprecision diamond tooling and they have been characterized (surface profile) by means of a measurement coordinate machine (Werth UA 400). After the characterization of the lenses, a setup of the channel with refocusing capability has been built up. In this setup it has been necessary to modify the distance between the tunable lens and the second passive lens, and between the second lens and the image sensor (uEye CMOS camera detector) with regards to the design specifications. Indeed, the fabricated lenses are not identical to the designed lens surfaces; there is one surface that has not been fabricated with the parameters of the design. The mounted refocusing channel performs well and the quality (contrast and ability to resolve fine details) of the captured images is high. In the experiments realized the working distances (object position) go from 0.15 m to 3 m, which is similar to the distance span obtained in the simulations for almost all the voltage values considered (from 51.1 Vrms to 60. The depth of field and depth of focus for different object distances and detector distances has been measured founding that the largest depth of field are obtained for low voltage values. In the experiments has been also observed that the tunable lens behaves hysterically (the optimal distance position where the image is sharp varies depending on the turning direction of the voltage, i.e., from higher to lower voltages values or viceversa.Ingeniería de TelecomunicaciónTelekomunikazio Ingeniaritz

Development Of A High Performance Mosaicing And Super-Resolution Algorithm

In this dissertation, a high-performance mosaicing and super-resolution algorithm is described. The scale invariant feature transform (SIFT)-based mosaicing algorithm builds an initial mosaic which is iteratively updated by the robust super resolution algorithm to achieve the final high-resolution mosaic. Two different types of datasets are used for testing: high altitude balloon data and unmanned aerial vehicle data. To evaluate our algorithm, five performance metrics are employed: mean square error, peak signal to noise ratio, singular value decomposition, slope of reciprocal singular value curve, and cumulative probability of blur detection. Extensive testing shows that the proposed algorithm is effective in improving the captured aerial data and the performance metrics are accurate in quantifying the evaluation of the algorithm

SPICA:revealing the hearts of galaxies and forming planetary systems : approach and US contributions

How did the diversity of galaxies we see in the modern Universe come to be? When and where did stars within them forge the heavy elements that give rise to the complex chemistry of life? How do planetary systems, the Universe's home for life, emerge from interstellar material? Answering these questions requires techniques that penetrate dust to reveal the detailed contents and processes in obscured regions. The ESA-JAXA Space Infrared Telescope for Cosmology and Astrophysics (SPICA) mission is designed for this, with a focus on sensitive spectroscopy in the 12 to 230 micron range. SPICA offers massive sensitivity improvements with its 2.5-meter primary mirror actively cooled to below 8 K. SPICA one of 3 candidates for the ESA's Cosmic Visions M5 mission, and JAXA has is committed to their portion of the collaboration. ESA will provide the silicon-carbide telescope, science instrument assembly, satellite integration and testing, and the spacecraft bus. JAXA will provide the passive and active cooling system (supporting the

The Apertif Surveys:The First Six Months

Apertif is a new phased-array feed for the Westerbork Synthesis Radio Telescope (WSRT), greatly increasing its field of view and turning it into a natural survey instrument. In July 2019, the Apertif legacy surveys commenced; these are a time-domain survey and a two-tiered imaging survey, with a shallow and medium-deep component. The time-domain survey searches for new (millisecond) pulsars and fast radio bursts (FRBs). The imaging surveys provide neutral hydrogen (HI), radio continuum and polarization data products. With a bandwidth of 300 MHz, Apertif can detect HI out to a redshift of 0.26. The key science goals to be accomplished by Apertif include localization of FRBs (including real-time public alerts), the role of environment and interaction on galaxy properties and gas removal, finding the smallest galaxies, connecting cold gas to AGN, understanding the faint radio population, and studying magnetic fields in galaxies. After a proprietary period, survey data products will be publicly available through the Apertif Long Term Archive (ALTA, https://alta.astron.nl). I will review the progress of the surveys and present the first results from the Apertif surveys, including highlighting the currently available public data

Vers l'intégration de fonctions d'imagerie sur le plan focal infrarouge Application à la conception et à la réalisation d'une caméra sur puce infrarouge cryogénique

La miniaturisation des systèmes optiques est un domaine de recherche qui suscite un grand intérêt scientifique actuellement. En effet, moins volumineux et moins chers, ils peuvent prétendre à être diffusés dans des applications diverses. L'objectif de cette thèse est de concevoir des systèmes d'imagerie extrêmement compacts, intégrés au plus près du détecteur infrarouge refroidi, et idéalement solidaires de celui-ci. Des travaux de recherche sont actuellement menés pour miniaturiser les systèmes optiques : moins volumineux et moins chers, ils peuvent prétendre à être diffusés dans des applications diverses. L'objectif de cette thèse est de concevoir des systèmes d'imagerie extrêmement compacts, intégrés au plus près du détecteur infrarouge refroidi, et idéalement solidaires de celui-ci. J'ai tout d'abord mis en évidence des stratégies pour la simplification et la miniaturisation des systèmes optiques. Parmi elles, les approches menant à des systèmes multivoies semblent être les plus prometteuses pour concevoir des systèmes à la fois compacts et performants. J'ai alors proposé deux architectures multivoies simples, compactes et intégrées au plus près du détecteur infrarouge. La première, de champ d'observation égal à 120, intègre une matrice de microlentilles à quelques centaines de micromètres seulement du détecteur infrarouge : elle est qualifiée de caméra sur puce. Des défis technologiques ont dû être relevés pour réaliser ce composant. J'ai développé un algorithme de reconstruction d'images et évalué expérimentalement les performances de la caméra. Ce système produit, après traitements, une image échantillonnée au pas de 7,5 m. Cette valeur est deux fois meilleure que celle qui pourrait être obtenue avec une caméra monovoie classique, associée à un détecteur infrarouge à l'état de l'art actuel, avec un pas pixel de 15 m. J'ai contribué à la réalisation du second système en développant une méthode originale et simple pour en fabriquer les matrices de microlentilles. Cette technique consiste à mouler par compression de la poudre de bromure de potassium à température ambiante.Ces travaux ouvrent la voie à une nouvelle génération de détecteurs infrarouges, qui intègrent une fonction d'imagerie.Miniaturizing optical systems is a research area of great interest nowadays: if they were smaller and cheaper, optical systems could be widespread in many applications. This work aims at designing very compact optical systems for imagery applications, which could be integrated near the infrared cryogenic detector and ideally directly on it.First, I have presented original design strategies to simplify and miniaturize optical systems. Approaches which lead to multichannel systems seem to be the most interesting ones to design compact and effective systems. Then, I have proposed two multichannel optical architectures, which are simple, compact, and integrated near the infrared detector. The first camera, which has a field of view equal to 120, integrates a microlens array at a few hundreds of micrometers only of the infrared detector: it is called a wafer-level camera. Technological challenges have been overcome to manufacture this component. I have developed an image processing method, and assessed the characteristics of the camera experimentally. This system samples the final image with a pitch equal to 7,5 m. This value is two times better than the one which could be obtained by using a one-channel camera associated with a state-of-the-art infrared detector, with a pixel pitch equal to 15 m. In order to manufacture the second architecture, I have developed an original and simple method to obtain the microlens arrays, by compression molding of Potassium Bromide powder at ambient temperature. This work gives some elements to design a new generation of infrared detectors with an imagery function.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF