A cryogenic, 1-5 micron atmospheric dispersion corrector for astronomical adaptive optics

Roland J. Sarlot, Donald W. McCarthy

Research output: Contribution to journalConference articlepeer-review

2 Scopus citations


A cryogenic mechanism has been built to correct for the blurring effects of atmospheric dispersion in adaptive-optics images from large aperture telescopes. Steward Observatory's 6.5 m telescope features a deformable Cassegrain secondary mirror compensating for atmospheric turbulence at wavelengths from 1-5 microns. At 1 micron, smearing caused by atmospheric dispersion equals the diffraction-limited image width (0.04 arcseconds FWHM). In order to correct for this effect and to maintain the low thermal background provided by the adaptive secondary, we have designed and built a cryogenic (77 K) atmospheric dispersion corrector. Operating over a spectral range of 1-5 microns, two pairs of counter-rotating calcium/lithium-fluoride prisms provide diffraction-limited imaging over a field of 1.7 arcminutes at a zenith angle up to 45 degrees.

Original languageEnglish (US)
Pages (from-to)72-78
Number of pages7
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - Dec 1 2001
EventCurrent Developments in Lens Design and Optical Engineering II - San Diego, CA, United States
Duration: Jul 30 2001Jul 30 2001


  • Atmospheric dispersion
  • Cryogenic prisms
  • Infrared
  • MMT

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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