OSA's Digital Library

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: 918–920

Limits on achievable intensity reduction with an optical occulter: reply to comment

Wasyl Wasylkiwskyj and Shahram Shiri  »View Author Affiliations

JOSA A, Vol. 29, Issue 6, pp. 918-920 (2012)

View Full Text Article

Enhanced HTML    Acrobat PDF (110 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



External occulters for NASA exoplanet missions have been proposed as the means to suppressing the Poisson spot intensity by at least 10 orders of magnitude. The leading proposed external occulter shapes adhere to the binary petaled occulters with sharp petal tips. In a recent paper, Wasylkiwskyj and Shiri [J. Opt. Soc. Am. A 28, 1668 (2011)] (WS2011) investigated two forms of occulters: a binary petaled occulter and a circular partially transparent occulter. They showed that the achievable intensity reduction for a petal-style occulter is limited by the radii of curvature at the petal tips. For a partially transparent occulter they derived the optimum transparency function that minimizes the intensity on the optic axis within a prescribed wavelength range and provides the required intensity suppression. Since the publication of WS2011, a paper by Cash describes the analytical model of the occulter [Astrophys. J. 738, 76 (2011)] and recent commentary by Cash and Lo [J. Opt. Soc. Am. A 29, 913 (2012)] (CL2011) compares the intensity reduction of petal shape functions and concludes prematurely against the petal shapes in WS2011. In this correspondence, we analyze the performance of a petal shaped occulter with petals tips of 0.1 mm width (following the prescription of CL2011) and show that its suppression performance is compatible with the calculations reported in WS2011 and measured intensity reduction reported in [Proc. SPIE 6687, 66871B (2007)] and [Proc. SPIE 6693, 669305 (2007)].

© 2012 Optical Society of America

OCIS Codes
(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: December 9, 2011
Revised Manuscript: February 15, 2012
Manuscript Accepted: February 19, 2012
Published: May 18, 2012

Wasyl Wasylkiwskyj and Shahram Shiri, "Limits on achievable intensity reduction with an optical occulter: reply to comment," J. Opt. Soc. Am. A 29, 918-920 (2012)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. W. Cash and A. Lo, “Limits on achievable intensity reduction with an optical occulter: comment,” J. Opt. Soc. Am. A 29, 913–917 (2012).
  2. W. Wasylkiwskyj and S. Shiri, “Limits on achievable intensity reduction with an optical occulter,” J. Opt. Soc. Am. A 28, 1668–1676 (2011). [CrossRef]
  3. C. J. Copi and G. D. Starkman, “The Big Occulting Steerable Satellite (BOSS),” Astrophys. J. 532, 581–592 (2000). [CrossRef]
  4. W. Cash, “Analytic modeling of starshades,” Astrophys. J. 738, 76 (2011). [CrossRef]
  5. D. B. Leviton, W. C. Cash, B. Gleason, M. J. Kaiser, S. A. Levine, A. S. Lo, E. Schindhelm, and A. F. Shipley, “White-light demonstration of one hundred parts per billion irradiance suppression in air by new starshade occulters,” Proc. SPIE 6687, 66871B (2007). [CrossRef]
  6. E. Schindhelm, A. Shipley, P. Oakley, D. Leviton, W. Cash, and G. Card, “Laboratory studies of petal-shaped occulters,” Proc. SPIE 6693, 669305 (2007). [CrossRef]
  7. A. B. Schultz, I. J. E. Jordan, M. Kochte, D. Fraquelli, F. Bruhweiler, J. M. Hollis, K. G. Carpenter, R. G. Lyon, M. DiSanti, C. Miskey, J. Leitner, R. D. Burns, S. R. Starin, M. Rodrigue, M. S. Fadali, D. Skelton, H. M. Hart, F. Hamilton, and K. P. Cheng, “UMBRAS: a matched occulter and telescope for imaging extrasolar planets,” Proc. SPIE 4860, 54–61 (2003). [CrossRef]

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.


Fig. 1. Fig. 2.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited