Rapid refocusing system for the Euro50 telescope aimed at removing the perspective elongation of laser beacons
Författare
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.
Avdelning/ar
Publiceringsår
2003
Språk
Engelska
Sidor
123-136
Publikation/Tidskrift/Serie
Society of Photo-Optical Instrumentation Engineers. Proceedings
Volym
5169
Dokumenttyp
Artikel i tidskrift
Förlag
Society of Photo-Optical Instrumentation Engineers
Ämne
- Astronomy, Astrophysics and Cosmology
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0361-0748