Share Email Print
cover

Proceedings Paper

Demonstration of 17 cm robust carbon fiber deformable mirror for adaptive optics
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

Carbon-fiber reinforced polymer (CFRP) composite is an attractive material for fabrication of optics due to its high stiffness-to-weight ratio, robustness, zero coefficient of thermal expansion (CTE), and the ability to replicate multiple optics from the same mandrel. We use 8 and 17 cm prototype CFRP thin-shell deformable mirrors to show that residual CTE variation may be addressed with mounted actuators for a variety of mirror sizes. We present measurements of surface quality at a range of temperatures characteristic of mountaintop observatories. For the 8 cm piece, the figure error of the Al-coated reflective surface under best actuator correction is ~43 nm RMS. The 8 cm mirror has a low surface error internal to the outer ring of actuators (17 nm RMS at 20°C and 33 nm RMS at -5°C). Surface roughness is low (< 3 nm P-V) at a variety of temperatures. We present new figure quality measurements of the larger 17 cm mirror, showing that the intra-actuator figure error internal to the outer ring of actuators (38 nm RMS surface with one-third the actuator density of the 8 cm mirror) does not scale sharply with mirror diameter.

Paper Details

Date Published: 16 September 2011
PDF: 10 pages
Proc. SPIE 8149, Astronomical Adaptive Optics Systems and Applications IV, 81490C (16 September 2011); doi: 10.1117/12.894186
Show Author Affiliations
S. Mark Ammons, Lawrence Livermore National Lab. (United States)
Michael Hart, Steward Observatory, The Univ. of Arizona (United States)
Blake Coughenour, College of Optical Sciences, The Univ. of Arizona (United States)
Robert Romeo, Composite Mirror Applications, Inc. (United States)
Robert Martin, Composite Mirror Applications, Inc. (United States)
Matt Rademacher, Steward Observatory, The Univ. of Arizona (United States)


Published in SPIE Proceedings Vol. 8149:
Astronomical Adaptive Optics Systems and Applications IV
Robert K. Tyson; Michael Hart, Editor(s)

© SPIE. Terms of Use
Back to Top