Interferometric coronography for the DARWIN space mission { Laboratory demonstration experiment

The DARWIN mission aims at directly detecting exoplanets, particularly telluric ones, around nearby stars and at performing a spectral analysis of their potential atmosphere. The major diculty in achieving this goal is the huge luminosity contrast between the star and its possible planet(s). The mission concept is based on the star light rejection by nulling interferometry. This concept has never been experimentally demonstrated with high values of rejection (10 5 ) in the thermal infrared where DARWIN will observe. In this paper, we describe a laboratory test-bed that uses a CO2 laser at 10.6 m to achieve this goal in a monochromatic case. We describe its principle, its sub-systems, their realizations and the rst results we obtained with this interferometer.