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

Beckers, Jacques M; Owner-Petersen, Mette LU and Andersen, Torben LU (2003) In Society of Photo-Optical Instrumentation Engineers. Proceedings 5169. p.123-136
Abstract
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... (More)
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. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Society of Photo-Optical Instrumentation Engineers. Proceedings
volume
5169
pages
123 - 136
publisher
Society of Photo-Optical Instrumentation Engineers
ISSN
0361-0748
DOI
10.1117/12.504238
language
English
LU publication?
yes
id
56997ed2-2bfa-4872-87b0-1b667f09004e (old id 130410)
date added to LUP
2007-07-12 13:57:58
date last changed
2016-04-16 03:53:55
@article{56997ed2-2bfa-4872-87b0-1b667f09004e,
  abstract     = {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.},
  author       = {Beckers, Jacques M and Owner-Petersen, Mette and Andersen, Torben},
  issn         = {0361-0748},
  language     = {eng},
  pages        = {123--136},
  publisher    = {Society of Photo-Optical Instrumentation Engineers},
  series       = {Society of Photo-Optical Instrumentation Engineers. Proceedings},
  title        = {Rapid refocusing system for the Euro50 telescope aimed at removing the perspective elongation of laser beacons},
  url          = {http://dx.doi.org/10.1117/12.504238},
  volume       = {5169},
  year         = {2003},
}