Demonstration of 17 cm robust carbon fiber deformable mirror for adaptive optics

S. Mark Ammons, Michael Hart, Blake Coughenour, Robert Romeo, Robert Martin, Matt Rademacher

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

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.

Original languageEnglish (US)
Title of host publicationAstronomical Adaptive Optics Systems and Applications IV
DOIs
StatePublished - Oct 21 2011
EventAstronomical Adaptive Optics Systems and Applications IV - San Diego, CA, United States
Duration: Aug 21 2011Aug 24 2011

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume8149
ISSN (Print)0277-786X

Other

OtherAstronomical Adaptive Optics Systems and Applications IV
CountryUnited States
CitySan Diego, CA
Period8/21/118/24/11

Keywords

  • CFRP
  • adaptive optics
  • adaptive secondary
  • carbon fiber
  • carbon fiber reinforced polymer
  • composite
  • deformable
  • thin-shell

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Demonstration of 17 cm robust carbon fiber deformable mirror for adaptive optics'. Together they form a unique fingerprint.

  • Cite this

    Ammons, S. M., Hart, M., Coughenour, B., Romeo, R., Martin, R., & Rademacher, M. (2011). Demonstration of 17 cm robust carbon fiber deformable mirror for adaptive optics. In Astronomical Adaptive Optics Systems and Applications IV [81490C] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 8149). https://doi.org/10.1117/12.894186