Adaptive optics development at the Giant Magellan Telescope: recent progress

In the past two years significant forward progress has been achieved in development of Adaptive Optics sensing and control technology needed for the observation modes of the Giant Magellan Telescope1. Most notable is the recent progress in demonstrating the accurate and stable control of segment piston in the diffraction-limited Natural Guide Star AO observation mode. Two NSF-funded testbeds have been successfully operated to validate the control algorithms for active optics, adaptive optics and segment piston in diffraction-limited observation. GMTO also built and operated wavefront sensor prototypes and integrated them with the testbeds. The testing has largely validated the wavefront sensor designs and has retired much of the fabrication and assembly risks. In parallel with the hardware demonstrations, significant progress has been achieved in both NGAO and LTAO control simulations verifying compliance with the required performance in each of these observation modes and thereby supporting the image quality budgets. In the area of design the GMTO Telescope Metrology Subsytem has passed its Preliminary Design Review and the conceptual design of the Adaptive Optics Test Camera has been completed. Finally, a Delta Preliminary Design phase for the LTAO hardware has begun.