OSA's Digital Library

Applied Optics

Applied Optics


  • Vol. 39, Iss. 22 — Aug. 1, 2000
  • pp: 3955–3962

Experimental study of external occulters for the Large Angle and Spectrometric Coronagraph 2: LASCO-C2

Maurice Bout, Philippe Lamy, André Maucherat, Claude Colin, and Antoine Llebaria  »View Author Affiliations

Applied Optics, Vol. 39, Issue 22, pp. 3955-3962 (2000)

View Full Text Article

Enhanced HTML    Acrobat PDF (573 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



To reduce the level of stray light in a new-generation externally occulted space coronagraph, we consider new concepts for its external occulter and its associated diaphragm and report extended measurements of their light-rejection properties. The experimental setup, which includes an artificial Sun, uses both photometric and CCD imaging techniques and permits the study of the sensitivity to misalignement of the instrument’s performance. Conic occulters that have either a multithreaded or a polished surface are found to give performances superior to those of the classical three-disk system and further are highly tolerant to misalignement. Serrated diaphragms outperform circular ones, as the bulk of the diffracted light is diverted from the coronagraphic objective.

© 2000 Optical Society of America

OCIS Codes
(220.4830) Optical design and fabrication : Systems design
(220.4840) Optical design and fabrication : Testing
(290.5820) Scattering : Scattering measurements
(350.1270) Other areas of optics : Astronomy and astrophysics
(350.4600) Other areas of optics : Optical engineering

Original Manuscript: January 3, 2000
Revised Manuscript: April 5, 2000
Published: August 1, 2000

Maurice Bout, Philippe Lamy, André Maucherat, Claude Colin, and Antoine Llebaria, "Experimental study of external occulters for the Large Angle and Spectrometric Coronagraph 2: LASCO-C2," Appl. Opt. 39, 3955-3962 (2000)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. G. Newkirk, D. Bohlin, “Reduction of scattered light in the coronagraph,” Appl. Opt. 2, 131–140 (1963). [CrossRef]
  2. J. W. Evans, “A photometer for measurement of sky brightness near the Sun,” J. Opt. Soc. Am. 38, 1083–1085 (1948). [CrossRef] [PubMed]
  3. J. D. Purcell, M. J. Koomen, “Coronagraph with improved scattered-light properties,” J. Opt. Soc. Am. 52, 596–597 (1962).
  4. B. Fort, C. Forel, G. Spaak, “The reduction of scattered light in an external occulting disk coronagraph,” Astron. Astrophys. 63, 243–246 (1978).
  5. M. J. Koomen, C. R. Detwiler, G. E. Brueckner, H. W. Cooper, T. Tousey, “White light coronagraph in OSO-7,” Appl. Opt. 14, 743–751 (1975). [CrossRef] [PubMed]
  6. R. M. MacQueen, J. T. Gosling, E. Hildner, R. H. Munro, A. I. Poland, C. L. Ross, “The High Altitude Observatory white light coronagraph,” in Instrumentation in Astronomy II, D. H. Menzel, L. Larmore, D. Crawford, eds., Proc. SPIE44, 207–212 (1974). [CrossRef]
  7. N. R. Sheeley, D. J. Michels, R. A. Howard, M. J. Koomen, “Initial observations with the Solwind coronagraph,” Astrophys. J. 237, L99–L101 (1980). [CrossRef]
  8. R. M. MacQueen, A. Csoeke-Poeckh, E. Hildner, L. House, R. Reynolds, A. Stanger, H. Tepoel, W. Wagner, “The High Altitude Observatory Coronagraph/Polarimeter on the Solar Maximum Mission,” Solar Phys. 65, 91–107 (1980). [CrossRef]
  9. G. E. Brueckner, R. A. Howard, M. J. Koomen, C. M. Korendyke, D. J. Michels, D. G. Socker, K. P. Dere, P. L. Lamy, A. Llebaria, M.-V. Bout, R. Schwenn, G. M. Simnett, D. K. Bedford, D. J. Eyles, “The Large Angle Spectroscopic Coronagraph (LASCO),” Solar Phys. 162, 1–2, 357–402 (1995).
  10. S. Koutchmy, M. Belmahdi, “Improved measurements of scattered light levels behind occulting systems,” J. Opt. 18, 5–6, 265–269 (1987).
  11. D. Bohlin, NASA Headquarters, 300 E Street, SW, Washington, D.C. (personal communication, 15October1989).
  12. A. V. Lenskii, “Theoretical assessment of efficiency of coronagraph external occulting systems,” Astron. Zh. 58, 648–659 (1981) [Sov. Astron. 25(3), 366–372 (1981)].

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited