Towards 1st light of the 6.5 m MMT adaptive optics system with deformable secondary mirror

F. Wildi, G. Brusa, A. Riccardi, M. Lloyd-Hart, H. M. Martin, L. Close

Research output: Contribution to journalConference articlepeer-review

26 Scopus citations


In this communication, we present the progress of the 6.5 m MMT adaptive optics system. During the last part of 2001 and the 1st part of 2002, the system has been validated in the laboratory statically and dynamically with sample frequencies of up to 550 Hz. In June 2002, an attempt has been made to make this system work on the telescope but has been hampered by mechanical failures. However, ease of installation of the system and open-loop operation of the mirror was demonstrated at this occasion and offers reasons to be optimistic on the future of the system. The MMT-AO system is the first AO system to compensate the aberrated wavefront at the telescope's secondary mirror. This approach has unique advantages in terms of optical simplicity, high throughput and low emissivity. Its realization presents many technical challenges, which have now been overcome. Today, the deformable mirror is characterized and accepted. It features a 1.8 mm thick 640 mm diameter convex aspheric mirror (manufactured at the Steward Observatory Mirror Lab), mounted on a 50 mm thick ULE reference body with 336 actuators, as well as a cluster of 168 DSP's and associated analog circuitry for position sensing and actuator driving. The system has been characterized in the laboratory at sampling speeds up to 550 Hz and had been integrated on the telescope.

Original languageEnglish (US)
Pages (from-to)155-163
Number of pages9
JournalProceedings of SPIE - The International Society for Optical Engineering
Issue number1
StatePublished - 2002
EventAdaptive Optical System Technologies II - Waikoloa, HI, United States
Duration: Aug 22 2002Aug 26 2002


  • Adaptive optics
  • Adaptive secondary
  • Thermal infrared

ASJC Scopus subject areas

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


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