Experimental results on wavefront correction using the self-coherent camera

  1. Get@NRC: Experimental results on wavefront correction using the self-coherent camera (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1117/12.926586
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Proceedings titleProceedings of SPIE - The International Society for Optical Engineering
ConferenceGround-Based and Airborne Instrumentation for Astronomy IV, 1 July 2012 through 6 July 2012, Amsterdam
Article number844689
SubjectCoronagraphy; High angular resolutions; High contrast imaging; Instrumentation; Wavefront correction; Aberrations; Astronomy; Cameras; Computer simulation; Detectors; Focusing; Speckle; Wavefronts
AbstractThe Self-Coherent Camera is dedicated to the direct detection of exoplanets. This instrument can be used as a focal plane wavefront sensor to measure static aberrations that induce speckles on the detector, which prevents the detection of faint companions. The Self-Coherent Camera creates a reference beam in the Lyot stop pupil plane in order to spatially modulate the speckle pattern with Fizeau fringes. We can then estimate for wavefront aberrations upstream of the coronagraphic mask and correct for them using a deformable mirror. Currently, the Self-Coherent Camera is combined with a deformable mirror located in the pupil plane upstream of a Four-Quadrant Phase Mask Coronagraph. In this paper, we present the formalism that explains how the Self-Coherent Camera encodes speckles and how we estimate the wavefront aberrations directly from the science image. We present numerical simulation results on speckle suppression in the focal plane. Then, we give experimental results on wavefront correction on our optical bench using a 32x32 actuators deformable mirror. We show that we can improve the contrast in the focal plane by a factor of more than 100 in the PSF wings up to 12λ/D. © 2012 SPIE.
Publication date
AffiliationNational Research Council Canada (NRC-CNRC); NRC Herzberg Institute of Astrophysics (HIA-IHA)
Peer reviewedYes
NPARC number21269497
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Record identifier257cd4f2-acba-45fa-9f8c-7b95fbc36fb3
Record created2013-12-12
Record modified2016-05-09
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