Development and recent results from the Subaru coronagraphic extreme adaptive optics system

N. Jovanovic, O. Guyon, F. Martinache, C. Clergeon, G. Singh, T. Kudo, K. Newman, J. Kuhn, E. Serabyn, B. Norris, P. Tuthill, P. Stewart, E. Huby, G. Perrin, S. Lacour, S. Vievard, N. Murakami, O. Fumika, Y. Minowa, Y. HayanoJ. White, O. Lai, F. Marchis, G. Duchene, T. Kotani, J. Woillez

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

14 Scopus citations


The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument is one of a handful of extreme adaptive optics systems set to come online in 2014. The extreme adaptive optics correction is realized by a combination of precise wavefront sensing via a non-modulated pyramid wavefront sensor and a 2000 element deformable mirror. This system has recently begun on-sky commissioning and was operated in closed loop for several minutes at a time with a loop speed of 800 Hz, on ∼150 modes. Further suppression of quasi-static speckles is possible via a process called "speckle nulling" which can create a dark hole in a portion of the frame allowing for an enhancement in contrast, and has been successfully tested on-sky. In addition to the wavefront correction there are a suite of coronagraphs on board to null out the host star which include the phase induced amplitude apodization (PIAA), the vector vortex, 8 octant phase mask, 4 quadrant phase mask and shaped pupil versions which operate in the NIR (y-K bands). The PIAA and vector vortex will allow for high contrast imaging down to an angular separation of 1 λ/D to be reached; a factor of 3 closer in than other extreme AO systems. Making use of the left over visible light not used by the wavefront sensor is VAMPIRES and FIRST. These modules are based on aperture masking interferometry and allow for sub-diffraction limited imaging with moderate contrasts of ∼100-1000:1. Both modules have undergone initial testing on-sky and are set to be fully commissioned by the end of 2014.

Original languageEnglish (US)
Title of host publicationGround-Based and Airborne Instrumentation for Astronomy V
EditorsSuzanne K. Ramsay, Ian S. McLean, Hideki Takami
ISBN (Electronic)9780819496157
StatePublished - 2014
EventGround-Based and Airborne Instrumentation for Astronomy V - Montreal, Canada
Duration: Jun 22 2014Jun 26 2014

Publication series

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


OtherGround-Based and Airborne Instrumentation for Astronomy V


  • Aperture masking interferometry
  • Coronagraphy
  • Exoplanetary science
  • Extreme adaptive optics
  • High contrast imaging
  • SCExAO
  • Small inner working angle

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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