Laser Guide Star Adaptive Optics Instrumentation Research at the AITC

The AITC is currently leading the design of three major Laser Guide Star Adaptive Optics (LGS AO) systems for large and extremely-large telescopes: Subaru GLAO, ESO MAVIS, and GMT LTAO. Let’s have a closer look at what these exciting acronyms actually mean in terms of LGS AO-enhanced observational power for our astronomer colleagues.

The ULTIMATE-Subaru GLAO project at the AITC is part of an extensive instrumentation research program led by our Japanese colleagues at the Subaru Telescope, that aims to equip the 8-m National Japanese Telescope on Maunakea (Hawaii) with state-of-the-art astronomical instrumentation: a wide-field near-infrared imager and a multi-object spectrograph both utilizing Ground Layer Adaptive Optics (GLAO) with 4 LGS to improve seeing by a factor of 2 or more across a large field of view of 20 arcmin in diameter. The ULTIMATE-Subaru GLAO project is a collaborative effort between the National Astronomical Observatory Japan (NAOJ) and ANU. The AITC is responsible for the development of the Laser Guide Star Facility and the Wavefront Sensor module as part of the GLAO project. The ULTIMATE-Subaru GLAO project held its Preliminary Design Review at the Subaru Telescope headquarters in Hawaii in November 2022 and will be starting its Final Design Phase at the AITC next month.

Meanwhile, at the European Southern Observatory on Cerro Paranal in Chile, MAVIS will aim to leverage the exceptional capabilities of the ESO Very Large Telescope (VLT) Adaptive Optics Facility (AOF) and push AO-enhanced VLT observations into the visible spectrum. MAVIS will implement a Multi-Conjugate AO and tomographic approach and use not 4 but 8 LGS to restore the VLT’s diffraction limit in the visible over a relatively large field of view of 30”x30”. The AITC is leading this exciting and challenging development to deliver unparalleled AO performance at the VLT in collaboration with our Astralis colleagues at Macquarie University (Astralis-AAO), INAF colleagues in Italy, and French colleagues in Marseille. MAVIS will hold its Preliminary Design Review at the ESO headquarters in Garching, Germany, at the end of this month.

After remaining dormant for over 10 years, The Laser Tomography Adaptive Optics (LTAO) project for the Giant Magellan Telescope is finally back in the AITC! The GMT LTAO system will cover a much smaller field of view (1 arcmin) than ULTIMATE-GLAO but it will do so over a much larger telescope aperture (~25m) to restore the exceptional diffraction-limited power of the GMT and feed our very own ANU-led GMT Integral Field Spectrograph, GMTIFS. Like we did 10 years ago during the preliminary design phase, the AITC will soon be leading the LTAO LGS wavefront sensor and LGS facility final design effort. The GMT LGS facility will propagate 6 lasers on sky and sense 6 artificial stars to reconstruct the atmospheric turbulence tomographically over a 1 arcmin diameter field. The project is expected to restart in a couple of months with a view to hold its Final Design Review in about 3 years time.

The extreme requirements of Laser Guide Star Adaptive Optics (LGS-AO) for both very and extremely large telescopes exhibit notable overlaps with the novel and ambitious technological demands of LGS-AO for laser communications and space situational awareness applications. As a result, AITC Research and Development initiatives on LGS technology act as a crucial link between these two strategic instrumentation programs (advanced laser communications and AO for astronomy).  

Laser Guide Star Adaptive Optics Instrumentation Research at the AITC is leading the way in advancing the observational capabilities of ground-based telescopes of all sizes. Projects like ULTIMATE-GLAO for Subaru, MAVIS for the VLT, and LTAO for the GMT, supplemented by state-of-the-art LGS technology research and development projects for both astronomy and space are keeping the AITC at the forefront of Laser Guide Star Adaptive Optics research and continue to position the ANU as a world leader in this field. 

Noelia Martinez & Celine d’Orgeville



Left: Subaru new Laser Guide Star Facility. Credit: NAOJ; Centre: ESO AOF facility. Credit: ESO/F. Kamphues; Right: A render of the future GMT at night. Credit: GMTO Corporation/Mason Media Inc.