Aims. We present a solution to improve the performance of coronagraphs for the detection of exo-planets. Methods. We simulate numerically several kinds of coronagraphic systems, with the aim of evaluating the gain obtained with an adaptive hologram. Results. The detection limit in flux ratio between a star and a planet ()observed with an apodized Lyot coronagraph characterized by wavefront bumpiness imperfections of (resp. )turns out to be increased by a factor of 103.4 (resp.105.1) when equipped with a hologram. Conclusions. This technique could provide direct imaging of an exo-Earth at a distance of 11 parsec with a space telescope such as the JWST with the optical quality of the HST. Key words: instrumentation: detectors - instrumentation: miscellaneous - stars: planetary systems - instrumentation: interferometers
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