Large Binocular Telescope Adaptive Optics System: New achievements and perspectives in adaptive optics

摘要

The Large Binocular Telescope (LBT) is a unique telescope featuring twoco-mounted optical trains with 8.4m primary mirrors. The telescope AdaptiveOptics (AO) system uses two innovative key components, namely an adaptivesecondary mirror with 672 actuators and a high-order pyramid wave-front sensor.During the on-sky commissioning such a system reached performances neverachieved before on large ground-based optical telescopes. Images with 40masresolution and Strehl Ratios higher than 80% have been acquired in H band (1.6micron). Such images showed a contrast as high as 10e-4. Based on theseresults, we compare the performances offered by a Natural Guide Star (NGS)system upgraded with the state-of-the-art technology and those delivered byexisting Laser Guide Star (LGS) systems. The comparison, in terms of skycoverage and performances, suggests rethinking the current role ascribed to NGSand LGS in the next generation of AO systems for the 8-10 meter classtelescopes and Extremely Large Telescopes (ELTs).