Investigations into the Pyramid wavefront sensor (P-WFS) have experimentally demonstrated the ability toachieve a better performance than with a standard Shack-Hartmann sensor (SH-WFS). Implementation on theLarge Binocular Telescope (LBT) provided the rst operational demonstration on a facility-class instrument ofa P-WFS on sky. The desire to implement a Pyramid on an Extremely Large Telescope (ELT) requires furthercharacterisation in order to optimise the performance and match our knowledge and understanding of otherwave-front sensors (WFSs).Within the framework of the European Extremely Large Telescope (E-ELT), the Laboratoire d'Astrophysiquede Marseille (LAM) is involved in the preparation of the Single Conjugate Adaptive Optics (SCAO) system ofHARMONI, E-ELT's 1st light integral eld spectrograph (IFU). The current baseline WFS for this adaptiveoptics system is a Pyramid WFS using a high speed and sensitive OCAM2 camera. At LAM we are currentlycarrying out laboratory demonstrations of a Pyramid-WFS, with the aim to fully characterise the behaviour ofthe Pyramid in terms of sensitivity and linear range. This will lead to a full operational procedure for the use ofthe Pyramid on-sky, assisting with current designs and future implementations. The nal goal is to provide anon sky comparison between the Pyramid and Shack-Hartmann at Observatoire de la C^ote d'Azur (OCA). Herewe present our experimental setup and preliminary results.

The SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument aims at detecting extremely faintsources (giant extrasolar planets) in the vicinity of bright stars1. Such a challenging goal requires the use of a very-highorderperformance Adaptive Optics [AO] system feeding the scientific instruments with a quasi-perfect flat wave frontcorrected from all the atmospheric turbulence and internal defects. This AO system, called SAXO (Sphere Ao foreXoplanet Observation) is the heart of the instrument, a heart beating 1200 time per second and providing unprecedentedimage quality for a large ground based telescope at optical/near infrared wavelength. We will present the latest resultsobtained on-sky, demonstrating its exceptional performance (in terms of correction quality, stability and robustness) andtremendous potentiality for exoplanet discovery

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.

We analyze the altitude distribution of the turbulence outer scale - L0(h) - at Cerro Pachón from Gemini South MCAO (GeMS) loop data. GeMS turbulence profiler is fed with telemetry from their 5 WFSs and from the voltages applied to the deformable mirrors, providing estimations of r0, Cn2(h), wind profile (speed and direction for every layer), isoplanatic angle and the outer scale distribution L0(h). It is shown that this last parameter ranges from less than 1 meter at the ground to more than 50m (the telescope is insensitive to larger cannot detect differences above this value). The technique is based on cross correlations of the pseudo-open-loop slopes that allow to disentangle the multiple constituents of L0.

The SPHERE instrument (Beuzit, et al., 2010) is dedicated to the direct imaging of extra-solar planets. This kind of observation allows one to study the photons emitted by the planet’s atmosphere itself, or reflected by its surface. The search for bio-markers is therefore made possible. The SPHERE instrument has been installed and commissioned at VLT Paranal Observatory during 2014 and now routinely delivers high contrast images to the exoplanet community. This paper presents a study of the main actual limitation of the SPHERE instrument, as known as the Low Wind Effect [LWE]. This effect has been discovered on SPHERE during commissioning period. Its effect is a strong degradation of the instrument PSF, preventing instrument to perform high contrast imaging. It happens during particularly low wind conditions (below 1m/s at the telescope level) which happens one night out of five.