Image quality and high contrast improvements on VLT/NACO

Julien H.V. Girard, Jared O'Neal, Dimitri Mawet, Markus Kasper, Gérard Zins, Benoît Neichel, Johann Kolb, Valentin Christiaens, Martin Tourneboeuf

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

6 Citations (Scopus)


NACO* Nasmyth Adaptive Optics System NAOS and the Near-Infrared Imager and Spectrograph CONICA NACO* is the famous and versatile diffraction limited NIR imager and spectrograph with which ESO celebrated 10 years of Adaptive Optics at the VLT. Since two years a substantial effort has been put in to understanding and fixing issues that directly affect the image quality and the high contrast performances of the instrument. Experiments to compensate the non-common-path aberrations and recover the highest possible Strehl ratios have been carried out successfully and a plan is hereafter described to perform such measurements regularly. The drift associated to pupil tracking since 2007 was fixed in October 2011. NACO is therefore even better suited for high contrast imaging and can be used with coronagraphic masks in the image plane. Some contrast measurements are shown and discussed. The work accomplished on NACO will serve as reference for the next generation instruments on the VLT, especially those working at the diffraction limit and making use of angular differential imaging (i.e. SPHERE,1 VISIR,2 and possibly ERIS3).

Original languageEnglish
Title of host publicationAdaptive Optics Systems III
Number of pages14
Publication statusPublished - 1 Dec 2012
Externally publishedYes
EventAdaptive Optics Systems III - Amsterdam, Netherlands
Duration: 1 Jul 20126 Jul 2012


ConferenceAdaptive Optics Systems III


  • Adaptive optics
  • Calibration
  • High angular resolution
  • High contrast imaging
  • Infrared astronomy
  • Phase diversity
  • Strehl ratio
  • Very large telescope

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