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Snapshot coronagraphy with an interferometer in space

A. Boccaletti·P. Riaud·C. Moutou·A. Labeyrie
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Abstract

Diluted arrays of many optical apertures will be able to provide h igh-resolution snapshot images if the beams are combined according to the densified-pupil scheme. We show that the same principle can also provide coronagraphic images, for detecting faint sources near a bright unresolved one. Recent refinements of coronagraphic techniques, i.e. the use of a phase mask, active apodization and dark-speckle analysis, are also applicable for enhanced contrast. Implemented in the form of a proposed 50-500m Exo-Earth Discoverer array in space, the principle can serve to detect Earth-like exo-planets in the infra-red. It can also provide images of faint nebulosity near stars, active galactic nuclei and quasars. Calculations indicate that exo-planets are detectable amidst the zodiacal and exo-zodiacal emission faster than with a Bracewell array of equivalent area, a consequence of the spatial selectivity in the image.

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A. Boccaletti, P. Riaud, C. Moutou, A. Labeyrie. 2000-02-10. Snapshot coronagraphy with an interferometer in space. https://doi.org/10.1006/icar.2000.6347

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