On-sky speckle nulling with the Subaru Coronagraphic Extreme AO (SCExAO) instrument

Frantz Martinache, Olivier Guyon, Nemanja Jovanovic, Christophe Clergeon, Garima Singh, Tomoyuki Kudo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

8 Scopus citations


Contrast limit for the direct imaging of extrasolar planets from ground based adaptive optics (AO) observations is set by the presence of static and slow-varying aberrations in the optical path that lead to the science instrument. To complement the otherwise highly successful angular differential imaging (ADI) technique toward small angular separation, we propose to employ additional wavefront control to modulate the diffraction. This flexible approach introduces enough diversity to discriminate genuine structures of the observed target from spurious diffraction features in the image. One possible implementation of such form of coherence differential imaging (CDI) is a speckle nulling algorithm that iteratively suppresses diffraction features inside a region constrained by the number of active elements of the deformable mirror modulating the wavefront, and the coronagraph. This paper presents on-sky results obtained with this approach, on the Subaru Coronagraphic Extreme AO (SCExAO) instrument.

Original languageEnglish (US)
Title of host publicationAdaptive Optics Systems IV
EditorsJean-Pierre Veran, Enrico Marchetti, Laird M. Close
ISBN (Electronic)9780819496164
StatePublished - 2014
EventAdaptive Optics Systems IV - Montreal, Canada
Duration: Jun 22 2014Jun 27 2014

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherAdaptive Optics Systems IV

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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