The Subaru coronagraphic extreme AO (SCExAO) system: using new approaches for high contrast imaging on a large telescope


Vincent Garrel (1,2), Olivier Guyon (1), Pierre Baudoz (2), Frantz Martinache (1), Faustine Cantalloube (1)


NAOJ Subaru Telescope (1); Paris Observatory (2)


SCExAO is a flexible platform designed to be inserted between the existing coronagraphic camera HiCIAO and the AO188 Subaru system. It achieves high constrast imaging at small angular separation through a set of innovative techniques. SCExAO performs fine wavefront correction and calibration using a 1K MEMS. The wavefront control architecture is optimized for high contrast imaging, and includes a dedicated low order wavefront sensor using light reflected by the coronagraph focal plane mask. Thanks to custom optics able to remove spiders from the telescope pupil, and PIAA lenses performing lossless beam apodization, SCExAO efficiently delivers high contrast as close as 1λ/D. The platform also offers a visible diffraction imaging mode based on a fast frame rate photon counting camera combined with a new data processing algorithm. It also includes an aperture masking mode. SCExAO is currently under integration and testing, and is scheduled for first light on the Subaru Telescope in early 2011.

Attached documents

Lyot2010proc s7 talk GarrelV.pdf
PDF, 12.7 Mb