The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Torben Anderssen. Profile picture.

Torben Andersen

Professor emeritus (Leave of Absence)

Torben Anderssen. Profile picture.

Rapid refocusing system for the Euro50 telescope aimed at removing the perspective elongation of laser beacons

Author

  • Jacques M Beckers
  • Mette Owner-Petersen
  • Torben Andersen

Summary, in English

To obtain full sky coverage, astronomical adaptive optics systemsrequire Na Sodium Beacons (SBs) (also referred to as Laser Guide Starsor LGSs) located at heights extending from 85 to 100 km. When viewed atthe edge of large telescopes these SBs appear elongated. For the Euro5050 meter aperture telescopes this elongation amounts to 6 to 9arcseconds when the laser is launched from a point on the telescopeaxis. This is substantially larger than the ~0.6 arcsec FWHM SB whenviewed near the telescope center. This so-called "perspectiveelongation" substantially decreases the sensitivity of SB aided adaptiveoptics. We describe a way of removing this elongation when using pulsedlasers. It uses rapid (microsecond) refocusing of the telescope with theaid of birefringent lenses and polarization modulators. We present anoutline of the SB wavefront sensor for the Euro50.

Department/s

  • Lund Observatory - Undergoing reorganization

Publishing year

2003

Language

English

Pages

123-136

Publication/Series

Society of Photo-Optical Instrumentation Engineers. Proceedings

Volume

5169

Document type

Journal article

Publisher

Society of Photo-Optical Instrumentation Engineers

Topic

  • Astronomy, Astrophysics and Cosmology

Status

Published

ISBN/ISSN/Other

  • ISSN: 0361-0748