The Phase Induced Amplitude Apodization Complex Mask Coronagraph (PIAACMC) is an architecture for directly observing extrasolar planets, and can achieve performance near the theoretical limits for any direct-detection instrument. The PIAACMC architecture includes aspheric PIAA optics, and a complex phase-shifting focal plane mask that provides a pi phase shift to a portion of the on-axis starlight. The phase-shifted starlight is forced to interfere destructively with the un-shifted starlight, causing the starlight to be eliminated, and allowing a region for high-contrast imaging near the star. The PIAACMC architecture can be designed for segmented and obscured apertures, so it is particularly well suited for ground-based observing with the next generation of large telescopes. There will be unique scientific opportunities for directly observing Earth-like planets around nearby low-mass stars. We will discuss design strategies for adapting PIAACMC for the next generation of large ground-based telescopes, and present progress on the development of the focal plane mask technology. We also present simulations of wavefront control with PIAACMC, and suggest directions to apply the coronagraph architecture to future telescopes.

Diamond is a material with many exceptional properties. In this thesis methods for fabrication of microstructures as well as several applications of such structures in optics, microfluidics and electrochemistry are presented. A method for etching deep and highly precise gratings is described. This method was used to fabricate circularly symmetric half wave plates for use in vector vortex coronagraphs. Such coronagraphs are a very promising approach to the direct imaging of extrasolar planets. By varying the lateral etch rate of the aluminum mask during diamond etching in an inductively coupled plasma, the sidewall angle of the etched structures could be controlled. This method was used to make smooth sloped sides on a waveguide for coupling light into it. Antireflective structures that drastically reduced the surface reflection in a wavelength band between 10 and 50 µm were also fabricated. An array of boron doped diamond microelectrodes for electrochemical measurements in a microchannel was fabricated and tested, showing very good stability and reusability. Several hundred hours of use did not adversely affect their performance and no damage to them could be detected by atomic force microscopy or scanning electron microscopy. Superhydrophobic surfaces in diamond were demonstrated, using both hydrogen and fluorine termination. Hydrogen termination on a flat surface gives contact angles below 90°. To achieve a superhydrophobic surface with this low intrinsic hydrophobicity, structures looking like microscopic nail heads were fabricated. The effect of water pressure on immersed superhydrophobic surfaces was also studied and it was found that the collapse of the superhydrophobic state due to pressure was sometimes reversible as the pressure was lowered. Finally, a method was tested for functionalizing diamond surfaces using block copolymers of polyethylene oxide and polypropylene oxide to both passivate the surface and to attach synthetic binder molecules. This method was found to give very high signal to noise ratios when detecting C-reactive protein.

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The search for life on other worlds is an exciting scientific endeavor that could change the way we perceive our place in the universe. Thousands of extrasolar planets have been discovered using indirect detection techniques. One of the most promising methods for discovering new exoplanets and searching for life is direct imaging with a coronagraph. Exoplanet coronagraphy of Earth-like planets is a challenging task, but we have developed many of the tools necessary to make it feasible. The Phase-Induced Amplitude Apodization (PIAA) Coronagraph is one of the highest-performing architectures for direct exoplanet imaging. With a complex phase-shifting focal plane mask, the PIAA Complex Mask Coronagraph (PIAACMC) can approach the theoretical performance limit for any direct detection technique. The architecture design is flexible enough to be applied to any arbitrary aperture shape, including segmented and obscured apertures. This is an important feature for compatibility with next-generation ground and space-based telescopes. PIAA and PIAACMC focal plane masks have been demonstrated in monochromatic light. An important next step for high-performance coronagraphy is the development of broadband phase-shifting focal plane masks. In this dissertation, we present an algorithm for designing the PIAA and PIAACMC focal plane masks to operate in broadband. We also demonstrate manufacturing of the focal plane masks, and show laboratory results. We use simulations to show the potential performance of the coronagraph system, and the use of wavefront control to correct for mask manufacturing errors. Given the laboratory results and simulations, we show new areas of exoplanet science that can potentially be explored using coronagraph technology. The main conclusion of this dissertation is that we now have the tools required to design and manufacture PIAA and PIAACMC achromatic focal plane masks. These tools can be applied to current and future telescope systems to enable new discoveries in exoplanet science.

Artifacts in polarimeters are apparent polarization features which are not real but result from the systematic errors in the polarimeter. The polarization artifacts are different between division of focal plane, spectral, and time modulation polarimeters. Artifacts result from many sources such as source properties, micropolarizer arrays, coatings issues, vibrations, and stress birefringence. A modeling examples of polarization artifacts due to a micro-polarizer array polarimeter is presented.

The point spread function (PSF) for astronomical telescopes and instruments depends not only on geometric aberrations and scalar wave diffraction, but also on the apodization and wavefront errors introduced by coatings on reflecting and transmitting surfaces within the optical system. Geometrical ray tracing provides incomplete image simulations for exoplanet coronagraphs with the goal of resolving planets with a brightness less than 10<^>-9 of their star located within 3 Airy disk radii. The Polaris-M polarization analysis program calculates uncorrected coating polarization aberrations couple around 10<^>-5 light into crossed polarized diffraction patterns about twice Airy disk size. These wavefronts not corrected by the deformable optics systems. Polarization aberrations expansions have shown how image defects scale with mirror coatings, fold mirror angles, and numerical aperture.

Complex-mask coronagraphs destructively interfere unwanted starlight with itself to enable direct imaging of exoplanets. This is accomplished using a focal plane mask (FPM); a FPM can be a simple occulter mask, or in the case of a complex-mask, is a multi-zoned device designed to phase-shift starlight over multiple wavelengths to create a deep achromatic null in the stellar point spread function. Creating these masks requires microfabrication techniques, yet many such methods remain largely unexplored in this context. We explore methods of fabrication of complex FPMs for a Phased-Induced Amplitude Apodization Complex-Mask Coronagraph (PIAACMC). Previous FPM fabrication efforts for PIAACMC have concentrated on mask manufacturability while modeling science yield, as well as assessing broadband wavelength operation. Moreover current fabrication efforts are concentrated on assessing coronagraph performance given a single approach. We present FPMs fabricated using several process paths, including deep reactive ion etching and focused ion beam etching using a silicon substrate. The characteristic size of the mask features is 5 mu m with depths ranging over 1 mu m. The masks are characterized for manufacturing quality using an optical interferometer and a scanning electron microscope. Initial testing is performed at the Subaru Extreme Adaptive Optics testbed, providing a baseline for future experiments to determine and improve coronagraph performance within fabrication tolerances.

On March 2015 an L'-band vortex coronagraph based on an Annular Groove Phase Mask made up of a diamond sub-wavelength grating was installed on NIRC2 as a demonstration project. This vortex coronagraph operates in the L' band not only in order to take advantage from the favorable star/planet contrast ratio when observing beyond the K band, but also to exploit the fact that the Keck II Adaptive Optics (AO) system delivers nearly extreme adaptive optics image quality (Strehl ratios values near 90%) at 3.7 mu m. We describe the hardware installation of the vortex phase mask during a routine NIRC2 service mission. The success of the project depends on extensive software development which has allowed the achievement of exquisite real-time pointing control as well as further contrast improvements by using speckle nulling to mitigate the effect of static speckles. First light of the new coronagraphic mode was on June 2015 with already very good initial results. Subsequent commissioning nights were interlaced with science nights by members of the VORTEX team with their respective scientific programs. The new capability and excellent results so far have motivated the VORTEX team and the Keck Science Steering Committee (KSSC) to offer the new mode in shared risk mode for 2016B.

L’imagerie d’exoplanètes est limitée par deux obstacles intrinsèques : le faible écart angulaire entre planète et étoile, et le très faible flux lumineux en provenance de la planète par rapport à la lumière de l’étoile. Le premier obstacle est surmonté par l’utilisation de très grands télescopes, de la classe des dix mètres de diamètre, et éventuellement depuis le sol de systèmes d’optique adaptative, qui permettent d’atteindre de hautes résolutions angulaires. Le deuxième obstacle est surmonté par l’utilisation de coronographes. Les coronographes sont des instruments conçus pour filtrer la lumière de l’étoile tout en laissant passer la lumière de l’environnement circumstellaire. Cependant, toute aberration optique en amont du coronographe engendre des fuites de lumière stellaire à travers le coronographe. Ces fuites se traduisent par un fouillis de tavelures dans les images scientifiques, tavelures qui cachent d’éventuelles planètes. Il est donc nécessaire de mesurer et de corriger les aberrations quasi-statiques à l’origine des tavelures. Cette thèse présente des contributions théoriques, numériques et expérimentales à la mesure et à la correction des aberrations des imageurs coronographiques. La première partie décrit le contexte et présente la méthode de la diversité de phase coronographique, un formalisme qui considère l’analyse de surface d’onde post-coronographique comme un problème inverse posé dans un cadre bayésien. La deuxième partie concerne l’imagerie depuis le sol. Elle présente tout d’abord une expression analytique permettant de modéliser l’imagerie coronographique en présence de turbulence, puis l’extension de la méthode de diversité de phase coronographique à la mesure depuis les télescopes au sol donc en présence de turbulence résiduelle, et enfin une validation en laboratoire de cette méthode étendue. La troisième partie est consacrée aux futurs imageurs spatiaux à très hauts contrastes pour lesquels il faut corriger non pas seulement la phase mais tout le champ complexe. Elle présente la validation en laboratoire de la mesure d’un champ complexe d’aberrations par diversité de phase coronographique, ainsi que des premiers résultats d’extinction de la lumière en plan focal par une méthode non linéaire, le non-linear dark hole. / Exoplanet imaging has two intrinsic limitations, namely the small angular separation between the star and the planet, and the very low light flux from the planet compared to the starlight. The first limitation is overcome by using very large telescopes of the ten-metre diameter class, and, for ground-based telescopes, adaptive optics systems, which allow high angular resolution imaging. The second limitation is overcome by using a coronagraph. Coronagraphs are optical devices which filter the starlight while granting passage to the light coming from the stellar environment. However, any optical aberration upstream of the coronagraph causes some of the starlight to leak through the coronagraph. This unfiltered starlight in turn causes speckles in the scientific images, and the light of the planets that could be there is lost among the speckles. Consequently, measurement and correction of the quasi-static aberration which generate the speckles are necessary for the exoplanet imagers to achieve their full potential. This thesis introduces theoretical, numerical, and experimental contributions to the topic of measurement and correction of the aberrations in coronagraphic imagers. The first part describes the context and introduces coronagraphic phase diversity, which is a Bayesian inverse problem formalism for post-coronagraphic wave-front sensing. The second part is focused on ground-based imaging. It introduces an analytic expression for coronagraphic imaging through turbulence, the extension of coronagraphic phase diversity to on-sky measurement through residual turbulence, and a laboratory validation of the extended method. The third part is concerned with future high-contrast space-based imagers, which will require not only phase correction, but a full complex wave-front correction. It presents the laboratory validation of coronagraphic phase diversity as a post-coronagraphic complex wave-front sensor, and first results of active contrast enhancement in the focal plane through thecreation of a non-linear dark hole.

Úkolem této práce je vytvoření adaptivního filtru pro vizualizaci CME v obrazech z kosmického koronografu, jejich implementování a výsledné testování na datech z kosmické sondy SOHO. V práci je zahrnuta potřebná teorie z oblasti astronomie a matematiky, popis NRGF, navrhnuté úpravy tohoto filtru a je přiložen program, který sloužil k jejich otestování.