The Subaru coronagraphic extreme AO (SCExAO) system: wavefront control and detection of exoplanets with coherent light modulation in the focal plane

The Subaru Coronagraphic Extreme-AO (SCExAO) system is designed for high contrast coronagraphic imaging at small angular separations, and is scheduled to see first light on the Subaru Telescope in early 2011. The wavefront control architecture for SCExAO is optimized for scattered light control and calibration at small angular separations, and is described in this paper. Key subsystems for the SCExAO wavefront control architecture have been successfully demonstrated, and we report results from these tests and discuss their role in the SCExAO system. Among these subsystems, a technique which can calibrate and remove static and slow speckles which traditionally limit high contrast detections is discussed. A visible light lab prototype system at Subaru Telescope recently demonstrated speckle halo reduction to 2e-7 contrast within 2 2λ/D, and removal of static coherent speckles to 3e-9 contrast.