A prototype phasing camera for the Giant Magellan Telescope

Srikrishna Kanneganti; Brian A. McLeod; Mark P. Ordway; John B. Roll Jr.; Stephen A. Shectman; Antonin H. Bouchez; Johanan Codona; Roger Eng; Thomas M. Gauron; Felix Handte; Timothy J. Norton; Phil Streechon; David Weaver

doi:10.1117/12.926517

13 September 2012 A prototype phasing camera for the Giant Magellan Telescope

Srikrishna Kanneganti, Brian A. McLeod, Mark P. Ordway, John B. Roll Jr., Stephen A. Shectman, Antonin H. Bouchez, Johanan Codona, Roger Eng, Thomas M. Gauron, Felix Handte, Timothy J. Norton, Phil Streechon, David Weaver

Author Affiliations +

Proceedings Volume 8447, Adaptive Optics Systems III; 844752 (2012) https://doi.org/10.1117/12.926517
Event: SPIE Astronomical Telescopes + Instrumentation, 2012, Amsterdam, Netherlands

Abstract

Achieving the diffraction limit with the adaptive optics system of the 25m Giant Magellan Telescope will require that the 7 pairs of mirror segments be in phase. Phasing the GMT is made difficult because of the 30-40cm gaps between the primary mirror segments. These large gaps result in atmospheric induced phase errors making optical phasing difficult at visible wavelengths. The large gaps between the borosilicate mirror segments also make an edge sensing system prone to thermally induced instability. We describe an optical method that uses twelve 1.5-m square subapertures that span the segment boundaries. The light from each subaperture is mapped onto a MEMS mirror segment and then a lenslet array which are used to stabilize the atmospherically induced image motion. Centroids for stabilization are measured at 700nm. The piston error is measured from the fringes visible in each of the 12 stabilized images at 2.2 microns. By dispersing the fringes we can resolve 2π phase ambiguities. We are constructing a prototype camera to be deployed at the 6.5m Magellan Clay telescope.

Citation Download Citation

Srikrishna Kanneganti, Brian A. McLeod, Mark P. Ordway, John B. Roll Jr., Stephen A. Shectman, Antonin H. Bouchez, Johanan Codona, Roger Eng, Thomas M. Gauron, Felix Handte, Timothy J. Norton, Phil Streechon, and David Weaver "A prototype phasing camera for the Giant Magellan Telescope", Proc. SPIE 8447, Adaptive Optics Systems III, 844752 (13 September 2012); https://doi.org/10.1117/12.926517

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available