Experimental advances in phase mask coronagraphy

Stellar coronagraphy is a key technology for current and future instruments for exoplanet imaging and spectroscopy, both on the ground and in space. We pursue the research on coronagraphs based on circular phase masks and report in this paper on recent advances in terms of the trade between spectral bandwidth and achievable contrast. Circular phase masks combined with colored apodizations prove to be promising options in such coronagraphic systems to reach high contrast gains within the search area over a wide band of wavelengths.