KalAO the swift adaptive optics imager on the 1.2m Euler Swiss telescope in la Silla, Chile

Janis Hagelberg, Nathanaël Restori, François Wildi, Bruno Chazelas, Christoph Baranec, Olivier Guyon, Ludovic Genolet, Michaël Sordet, Reed Riddle

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

3 Scopus citations


KalAO is a natural guide star adaptive optics (AO) imager to be installed on the second Nasmyth focus of the 1.2m Euler Swiss telescope in La Silla, Chile. The initial design of the system is inspired on RoboAO with modifications in order to operate in natural guide star (NGS) mode. KalAO was built to search for binarity in planet hosting stars by following-up candidates primarily from the TESS satellite survey. The optical design is optimised for the 450-900 nm wavelength range and is fitted with SDSS g,r,i,z filters. The system is designed for wavefront control down to I-magnitude 11 stars in order to probe the same parameter space as radial velocity instruments such as HARPS and NIRPS. The principal components of the system are an 11x11 10.9 cm sub-apertures Electron Multiplying CCD (EMCCD) Shack-Hartmann wavefront sensor, a 140 actuators Microelectromechanical systems (MEMS) deformable mirror, a fast tip/tilt mirror, and a graphics processing unit (GPU) powered glycol cooled real-time computer. It is designed to run at up to 1.8kHz in order to detect companions as close as the 150mas visible-light diffraction limit. The real-time adaptive optics control is using the CACAO software running on GPUs. The instrument is planned for commissioning early 2021 in Chile if the covid restrictions are lifted.

Original languageEnglish (US)
Title of host publicationAdaptive Optics Systems VII
EditorsLaura Schreiber, Dirk Schmidt, Elise Vernet
ISBN (Electronic)9781510636835
StatePublished - 2020
EventAdaptive Optics Systems VII 2020 - Virtual, Online, United States
Duration: Dec 14 2020Dec 22 2020

Publication series

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


ConferenceAdaptive Optics Systems VII 2020
Country/TerritoryUnited States
CityVirtual, Online


  • Adaptive optics
  • Astronomy
  • Exoplanets
  • Optics
  • Wave-front sensing

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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