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Journal of the Optical Society of America A

Journal of the Optical Society of America A


  • Editor: Franco Gori
  • Vol. 29, Iss. 6 — Jun. 1, 2012
  • pp: 913–917

Limits on achievable intensity reduction with an optical occulter: comment

Webster Cash and Amy Lo  »View Author Affiliations

JOSA A, Vol. 29, Issue 6, pp. 913-917 (2012)

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An external occulter is used as a means to suppress starlight and enable the observation of faint, Earth-like planets. A recent paper in this journal [J. Opt. Soc. Am. A 28, 1668 (2011)] suggested there were unrecognized limits on starlight intensity suppression with an external occulter. It claimed that, at the level of intensity reduction needed, tips of petal-shaped occulters are too small to be manufactured. We present analysis of that publication’s apodization function and show that it is mathematically distinct from the external occulter apodization functions being discussed in the literature. Their broad conclusion that the tips cannot be built is therefore invalid. They suggest that transmitting screens might be superior but do not explain why. We show their transmission function is substantially similar to those in use for the last five years and therefore may not represent an advance in the field.

© 2012 Optical Society of America

OCIS Codes
(050.1220) Diffraction and gratings : Apertures
(350.1260) Other areas of optics : Astronomical optics
(350.1270) Other areas of optics : Astronomy and astrophysics
(350.6090) Other areas of optics : Space optics

ToC Category:
Astronomical Optics

Original Manuscript: September 9, 2011
Revised Manuscript: October 27, 2011
Manuscript Accepted: October 28, 2011
Published: May 18, 2012

Webster Cash and Amy Lo, "Limits on achievable intensity reduction with an optical occulter: comment," J. Opt. Soc. Am. A 29, 913-917 (2012)

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