High contrast imaging and the search for young exo-planets

High contrast imaging has enormously progressed in the last twenty years, thanks to the development of extreme AO, efficient coronagraph, and various differential imaging techniques. The two frontier instruments are GPI at Gemini South and SPHERE at VLT. We are now routinely achieving contrast of better than 10^5 with a record of 4×10^6 at separations below 0.5 arcsec, This has allowed the discovery and characterization of about a dozen young planets, of a couple of dozens of brown dwarfs, and direct detection of several tens disks in scattered light. These data open new windows on the very early phases of planet formation, when disks are still present. Both theory and data indicate that while clearly planets form in the late phase of the protostellar disks, the relation between disk and planets is very complex. Also, the spectra we are obtaining for the young planets indicate systematic differences between young and old objects with similar temperature. I will briefly present the technological and scientific aspects of this very new and exciting science