SPHERE extreme AO system On-sky operation, final performance and future improvements

The SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument aims at detecting extremely faint1sources (giant extrasolar planets) in the vicinity of bright stars . Such a challenging goal requires the use of a very-high-order performance Adaptive Optics [AO] system feeding the scientific instruments with a quasi-perfect flat wave front corrected from all the atmospheric turbulence and internal defects. This AO system, called SAXO (Sphere Ao for eXoplanet Observation) is the heart of the instrument, a heart beating 1200 time per second and providing unprecedented image quality for a large ground based telescope at optical/near infrared wavelength. We will present the latest results obtained on-sky, demonstrating its exceptional performance (in terms of correction quality, stability and robustness) and tremendous potentiality for exoplanet discovery.