Picometer-Resolution MEMS Segmented DM
Project Description
Microelectromechanical systems (MEMS) technology has the potential to create deformable mirrors (DM) with 10^4 actuators that have size, weight, and power specifications that are far lower than conventional piezoelectric and electrostrictive DMs. However, building a MEMS DM with a relatively large aperture that is flat in the unpowered state is challenging. Currently, a large portion of the mirror stroke must be used to flatten the MEMS DMs. In the case of the large-stroke segmented MEMS DMs manufactured by Iris AO, there is sufficient stroke for wavefront correction after flattening. However, the resolution is significantly reduced because the dynamic range of the digital-to-analog converters (DAC) used to operate the DM is spread over multiple microns of stroke rather than the 0.5 micron range required for a coronagraph. This Phase I SBIR will make substantial improvements in the fabrication process of MEMS segmented DMs that reduce the deleterious residual surface-figure errors. It will do so by systematically addressing the sources of the segment position variations as well as addressing low-spatial frequency chip bow that can result in large peak-to-valley deformations across the DM array. The Iris AO DM architecture will also be modified to enable picometer resolution actuation with ultra-precision drive electronics.
More »Anticipated Benefits
The DM architecture developed here is a perfect match for visible nulling coronagraphs (VNC) that were studied for ATLAST, DAViNCI, and EPIC. In addition to the VNC, Iris AO technology can be a key enabling component in a host of future NASA missions that include Space Astronomy Far Infrared Telescope (SAFIR) Life Finder, and Planet Imager. Other potential programs such as Structure and Evolution of the Universe (SEU) and ultraviolet telescopes will also require adaptive optics. Finally, ground based telescopes, like the Thirty Meter Telescope (TMT), Keck, and Gemini North & South, require adaptive optics to remove aberrations caused by air turbulence.
In addition to NASA systems, the proposed adaptive-optics technology would find immediate application in several military communications and imaging products. Air Force and National Reconnaissance Office (NRO) both are interested in satellite AO. Systems used in military surveillance such as in the Predator drone and Global Hawk would benefit from the high-resolution, light weight, and low power consumption afforded by Iris AO's MEMS. Military contractors have also shown significant interest in using Iris AO technology for long range imaging through turbulent air. The thick mirror segments can be coated with dielectric coatings and are thus useful for laser-guidestar uplink corrections and beam shaping for laser machining. The DMs can also be used to correct horizontal-path aberrations for free-space laser communication links and reconnaissance. The segmented architecture is well suited for coupling beams to fibers for high-power lasers and fiber-based spectrographs.
Project Library
Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Iris AO, Inc. | Lead Organization | Industry | Berkeley, California |
Goddard Space Flight Center
(GSFC)
|
Supporting Organization | NASA Center | Greenbelt, Maryland |
Primary U.S. Work Locations
-
California
-
Maryland
