  The architecture of exoplanetary systems is relatively well known inward to 1
AU thanks to indirect techniques, which have allowed characterization of
thousands of exoplanet orbits, masses and sometimes radii. The next step is the
characterization of exoplanet atmospheres at long period, which requires direct
imaging capability. While the characterization of a handful of young giant
planets is feasible with dedicated instruments like SPHERE/VLT, GPI/Gemini,
SCExAO/Subaru and soon with the coronagraphic capabilities aboard JWST, the
spectroscopic study of mature giant planets and lower mass planets
(Neptune-like, Super Earths) requires the achievement of better coronagraphic
performance. While space-based coronagraph on WFIRST-AFTA might start this
study at low spectroscopic resolution, dedicated projects on large space
telescope and on the ELT will be required for a more complete spectroscopic
study of these faint planets. To prepare these future instruments, we developed
a high contrast imaging bench called THD, then THD2 for the upgraded version
using multi-DM configuration. The THD2 bench is designed to test and compare
coronagraphs as well as focal plane wavefront sensors and wavefront control
techniques. It can simulate the beam provided by a space telescope and soon the
first stage of adaptive optics behind a ground-based telescope. In this
article, we describe in details the THD2 bench and give the results of a recent
comparison study of the chromatic behavior for several coronagraph on the THD2.
