Extreme Adaptive Optics Coronagraphy with the High-Order Test bench in the context of the SPHERE instrument

Extreme adaptive optics systems (XAO) dedicated to the search for extrasolar planets are currently being developed for 8-10 meter telescopes. The High-Order Test bench (HOT) is a high-contrast imaging adaptive optics bench developed at the European Southern Observatory to test and optimize different techniques and technologies (e. g. wavefront sensors, coronagraphs, speckle calibration methods, image post-processing). It reproduces realistic conditions at a telescope (e. g. Very Large Telescope, VLT), including a turbulence generator, a high-order adaptive optics system, a near-IR coronagraph, and sequential differential imaging modes (spectral and polarimetric). We discuss the results of XAO coronagraphy obtained in the laboratory in the context of imminent planet-finder instruments (e. g. SPHERE(1), GPI(2), and HiCIAO(3)). In particular, results obtained with HOT will be discussed and compared with contrast goals of the near-IR camera of SPHERE.