Kelsey L. Miller

With the number of detections of smaller terrestrial planets beyond our solar system continually increasing with the success of missions like Kepler, the need for new technology to directly image and characterize these planets intensifies. Direct imaging of Earth-like planets presents multiple challenges due to the close proximity of the planet to its star coupled with the high star/planet contrast. To meet these constraints, larger telescopes are required in order to provide greater sensitivity and higher resolution, and more accurate star suppression systems are necessary to achieve better star/planet contrast. To directly image an orbiting planet, the light from the star must be suppressed with a high degree of precision, resulting in very tight wavefront control requirements. The University of Arizona Wavefront Control (UAWFC) Testbed has been built to help develop high efficiency wavefront measurement techniques on segmented and centrally obscured apertures for both ground and space-based observatories. The testbed is used to explore multiple telescope and coronagraph architectures, new hardware, and novel techniques for starlight suppression and wavefront control systems. My work on the testbed is focused on implementing and testing a new method of maintaining the light suppression in a region around a star where a planet would be orbiting. This method, called Linear Dark Field Control (LDFC), uses light outside the ‘dark hole’ to understand and control the light field in the suppressed region. The ability to maintain this ‘dark hole’ around a star will allow planet-imaging missions to see smaller, fainter planets closer to their star.