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Applied Optics

Applied Optics


  • Vol. 38, Iss. 4 — Feb. 1, 1999
  • pp: 704–713

Phase discontinuity sensing: a method for phasing segmented mirrors in the infrared

Gary Chanan, Mitchell Troy, and Edwin Sirko  »View Author Affiliations

Applied Optics, Vol. 38, Issue 4, pp. 704-713 (1999)

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We describe a novel method for phasing segmented optics in which the signal is the difference between inside-of-focus and outside-of-focus long-exposure infrared images. A detailed algorithm based on a correlation of this difference image with theoretical images or templates is presented. In a series of tests of this phase discontinuity sensing (PDS) algorithm at the Keck 1 telescope, at a wavelength of 3.3 µm, the rms piston error (averaged over the 36 primary mirror segments) was repeatedly reduced from approximately 240 to 40 nm or less. Furthermore, the PDS phasing solution was consistent with our previous phasing camera results (to within 66-nm rms), providing strong independent confirmation of this earlier approach.

© 1999 Optical Society of America

OCIS Codes
(010.7350) Atmospheric and oceanic optics : Wave-front sensing
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(350.1260) Other areas of optics : Astronomical optics

Original Manuscript: May 21, 1998
Revised Manuscript: October 19, 1998
Published: February 1, 1999

Gary Chanan, Mitchell Troy, and Edwin Sirko, "Phase discontinuity sensing: a method for phasing segmented mirrors in the infrared," Appl. Opt. 38, 704-713 (1999)

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