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Proceedings Paper

Amplitude variations on the ExAO testbed: Part II
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Paper Abstract

Micro-electrical-mechanical-systems (MEMS) deformable mirrors (DMs) are under study at the Laboratory for Adaptive Optics for inclusion in possible future adaptive optics systems, including open loop or extreme adaptive optics (ExAO) systems. MEMS DMs have several advantages in these areas because of low (to zero) hysterisis and high actuator counts. In this paper, we present work in the area of high-contrast adaptive optics systems, such as those needed to image extrasolar planets. These are known to require excellent wavefront control and diffraction suppression. On the ExAO testbed we have already demonstrated wavefront control of better than 1 nm rms within controllable spatial frequencies, however, corresponding contrast measurements are limited by amplitude variations, including variations introduced by the MEMS. Results from experimental measurements and wave optic simulations on the ExAO testbed will be presented. In particular the effect of small scale MEMS structures on amplitude variations and ultimately high-contrast far field measurements will be examined. Experimental results include interferometer measurements of phase and amplitude using the phase shifting diffraction interferometer, direct imaging of the pupil, and far-field imaging.

Paper Details

Date Published: 27 February 2008
PDF: 11 pages
Proc. SPIE 6888, MEMS Adaptive Optics II, 68880J (27 February 2008); doi: 10.1117/12.771766
Show Author Affiliations
Sandrine Thomas, Univ. of California at Santa Cruz (United States)
Julia W. Evans, Lawrence Livermore National Lab. (United States)
Donald Phillion, Lawrence Livermore National Lab. (United States)
Donald Gavel, Univ. of California at Santa Cruz (United States)
Daren Dillon, Univ. of California at Santa Cruz (United States)
Bruce Macintosh, Univ. of California at Santa Cruz (United States)
Lawrence Livermore National Lab. (United States)

Published in SPIE Proceedings Vol. 6888:
MEMS Adaptive Optics II
Scot S. Olivier; Thomas G. Bifano; Joel A. Kubby, Editor(s)

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