Adaptive optics for the next generation of extremely large telescopes (30 - 50 meter diameter primary mirrors) requires high-stroke (10 microns), high-order (100x100) deformable mirrors at lower-cost than current technology. Lowering the cost while improving the performance of deformable mirrors is possible using Micro-Electro-Mechanical Systems (MEMS) technology. In this paper the fabrication and testing of an array of high-stroke gold MEMS X-beam actuators attached to a continuous gold facesheet will be described. Both the actuator and the facesheet were fabricated monolithically in gold plated onto a thermally matched ceramic-glass substrate (WMS-15) using a high-aspect ratio fabrication process. Continuous facesheets that are deformed due to stress gradients have been annealed at high temperature and for an extended amount of time. The facesheet was flattened to the point where features such as etch holes and support post topography were easily distinguishable. Initial root-mean-square (RMS) topography at center of facesheet attached to a 16x16 X-beam actuator array with 1mm pitch was measured to be ~13.8μm. After annealing, the surface topography was measured to be ~1.0μm.

Date Published: 14 February 2011
PDF: 7 pages
Proc. SPIE 7931, MEMS Adaptive Optics V, 79310A (14 February 2011); doi: 10.1117/12.876530

Published in SPIE Proceedings Vol. 7931:
MEMS Adaptive Optics V
Scot S. Olivier; Thomas G. Bifano; Joel A. Kubby, Editor(s)