The CAFADIS camera: a new tomographic wavefront sensor for Adaptive Optics

Rodríguez, J. M.; Femenía, B.; Montilla, I.; Rodríguez-Ramos, L. F.; Marichal-Hernández, J. G.; Lüke, J. P.; López, R.; Díaz, J. J.; Martín, Y.
Bibliographical reference

1st AO4ELT conference - Adaptative Optics for Extremely Large Telescopes, held 22-26 June, 2009 in Paris, France. Edited by Y. Clénet, J.-M. Conan, Th. Fusco, and G. Rousset. EDP Sciences, 2010, id.05011

Advertised on:
2010
Number of authors
9
IAC number of authors
6
Citations
3
Refereed citations
3
Description
The CAFADIS camera is a new wavefront sensor (WFS) patented by the Universidad de La Laguna. CAFADIS is a system based on the concept of plenoptic camera originally proposed by Adelson and Wang [Single lens stereo with a plenoptic camera, IEEE Transactions on Pattern Analysis and Machine Intelligence 14 (1992)] and its most salient feature is its ability to simultaneously measuring wavefront maps and distances to objects [Wavefront and distance measurements using the CAFADIS camera, in Astronomical telescopes, Marseille (2008)]. This makes of CAFADIS an interesting alternative for LGS-based AO systems as it is capable of measuring from an LGS-beacon the atmospheric turbulence wavefront and simultaneously the distance to the LGS beacon thus removing the need of a NGS defocus sensor to probe changes in distance to the LGS beacon due to drifts of the mesospheric Na layer. In principle, the concept can also be employed to recover 3D profiles of the Na Layer allowing for optimizations of the measurement of the distance to the LGS-beacon. Currently we are investigating the possibility of extending the plenoptic WFS into a tomographic wavefront sensor. Simulations will be shown of a plenoptic WFS when operated within an LGS-based AO system for the recovery of wavefront maps at different heights. The preliminary results presented here show the tomographic ability of CAFADIS.