Orateur
Description
SPHERE has been a high-contrast instrument on sky at the Very Large Telescope since 2014. It makes infrared images of young giant planets, circumstellar disks, and characterizes them by spectroscopy and polarimetry. The next upgrade of SPHERE aims at improving the exoplanet detection capabilities, in particular closer to the star. To achieve this goal, the adaptive optics system will be improved by adding a second loop of correction, with a faster deformable mirror and a new type of wavefront sensor.
We use end-to-end numerical simulations of the two loops to quantify the improvement of the second loop and run a parametric study. The results are presented in terms of coronagraph images and stellar intensity profiles. We demonstrate an improvement of a factor 10 in residual intensity when adding the second loop. Finally, running the second loop at 2 kHz seems enough to get significant gain of performance.
In the future, a focal plane wavefront control loop will be added to the simulation to minimize the speckles intensities in the coronagraph images.
| Astrophysics Field | Instrumentation |
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