The next generation of ground- and space-based astronomical observatories will generate an increased requirement for lightweight and robust deformable optics. In space ultra-lightweight actively controlled mirrors will enable a continuing increase of aperture sizes, whilst large adaptive mirrors will become increasingly standard features in the optical design of adaptive optics-optimised Extremely Large Telescopes on the ground. This thesis presents results from a project to design, manufacture and test a prototype active mirror in a nickel-carbon fibre reinforced polymer (CFRP), which has been suggested in the literature to be a promising candidate material for such applications. Extensive finite element analysis results from gravitational sag and thermal models, as well as finite element-based predictions of the central actuator influence function profile, are presented. The main problems were encountered as a result of the in-mold nickel coating process, which resulted in residual form errors, and poor design of the support structures, leading to deterioration of the mirror surface quality. No fundamental reason ruling this material out for the use of precision deformable optics was identified. The finite element analysis results show significant promise for increased use of the method in optical design, as well as in integrated optical simulations for Extremely Large Telescopes.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:431764 |
| Date | January 2006 |
| Creators | Kendrew, Sarah |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1446451/ |
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