Translator Disclaimer
Presentation + Paper
13 December 2020 The Giant Magellan Telescope high contrast phasing testbed
Author Affiliations +
Abstract
The Giant Magellan Telescope design consists of seven circular 8.4 m diameter mirrors, together forming a single 24.5 m diameter primary mirror. This large aperture and collecting area can help extreme adaptive optics systems such as GMagAOX achieve the small angular resolutions and contrasts required to image habitable zone earth-like planets around late type stars and possibly lead to the discovery of life outside of our solar system. However, the GMT mirror segments are separated by large ⪆ 30 cm gaps, creating the possibility of fluctuations in optical path differences (piston) due to flexure, wind loading, temperature effects, and atmospheric seeing. In order to utilize the full diffraction-limited aperture of the GMT for high-contrast imaging, the seven mirror segments must be co-phased to well within a fraction of a wavelength. The current design of the GMT involves seven adaptive secondary mirrors, a dispersed fringe sensor (part of the AGWS), and a pyramid wavefront sensor (NGWS) to measure and correct the total path length between segment pairs, but these methods have yet to be tested “end-to-end” in a lab environment. We present the design and prototype of a “GMT High-Contrast Phasing Testbed” which leverages the existing MagAO-X ExAO instrument to demonstrate fine phase sensing and simultaneous AO-control for high-contrast GMT natural guide star science. The testbed will simulate the GMT primary and secondary mirror phasing system. It will also simulate the future GMT ExAO instrument’s (GMagAO-X) “parallel DM” tweeter concept of splitting up the GMT pupil onto several commercial DMs using a reflective hexagonal pyramid. A dispersed fringe sensor will also be implemented into the testbed for coarse piston phase-sensing along with MagAO-X’s pyramid wavefront sensor to measure and correct the fine phasing level of the GMT primary mirror segments under realistic wind load and seeing conditions.
Conference Presentation
© (2020) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Alexander D. Hedglen, Laird M. Close, Antonin H. Bouchez, Jared R. Males, Richard Demers, Maggie Kautz, Ritvik Basant, Makayla Parkinson, Victor Gasho, Fernando Quirós-Pacheco, and Breann N. Sitarski "The Giant Magellan Telescope high contrast phasing testbed", Proc. SPIE 11448, Adaptive Optics Systems VII, 114482X (13 December 2020); https://doi.org/10.1117/12.2559893
PROCEEDINGS
14 PAGES + PRESENTATION

SHARE
Advertisement
Advertisement
RELATED CONTENT

METIS: the mid-infrared E-ELT imager and spectrograph
Proceedings of SPIE (July 28 2014)
Rubin Observatory active optics system status
Proceedings of SPIE (December 13 2020)
High-contrast spectroscopy testbed for segmented telescopes
Proceedings of SPIE (January 22 2018)
The GTC project: preparing the first light
Proceedings of SPIE (June 23 2006)
The status of the Thirty Meter Telescope project
Proceedings of SPIE (July 17 2008)
The Giant Magellan Telescope (GMT)
Proceedings of SPIE (June 23 2006)

Back to Top