Extreme AO coronagraphy laboratory demonstration in the context of SPHERE


Martinez P., Aller Carpentier E., Kasper M.


European Southern Observatory


The exoplanetary science through direct imaging and spectroscopy will largely expand with the very soon raise of new instruments at the VLT (SPHERE), Gemini (GPI), and Subaru (HiCIAO) observatories. All these ground-based adaptive optics instruments include extremely high performance adaptive optics (XAO) system, advanced starlight cancellation techniques (e.g. coronagraphy), and speckle calibration techniques (e.g. spectral, angular, or polarimetry). In this context we report laboratory results obtained with the High-Order Test bench (HOT), the adaptive optics facility at the European Southern Observatory headquarters. Under 0.5 arcsec dynamical seeing, efficiently corrected by an XAO system delivering H-band Strehl ratio above 90%, we discuss contrast levels obtained with an apodized pupil Lyot coronagraph using differential imaging techniques (spectral and polarimetric). Accounting for system differences (e.g. deformable mirror actuator number), we demonstrate a good agreement between experimental results and expectations for SPHERE, or GPI, while we already met HiCIAO contrast goals.

Attached documents

Lyot2010proc s7 poster MartinezP.pdf
PDF, 5.5 Mb