Optical technologies for extremely-large telescopes

为了进一步了解宇宙，我们需要在地球和太空中安装新的强大的望远镜，其分辨率和灵敏度要比目前的设备高10到100倍。这些望远镜目前正在由世界各地的天文学家和工程师设计，将通过大口径和先进技术的结合来实现它们的能力。其中一项技术是自适应光学，它是未来所有大型地面望远镜的关键，因为它可以在很大程度上纠正大气湍流造成的模糊效应。下一代AO系统将需要高功率激光器和复杂的计算机控制变形镜。激光被用来照亮由流星沉积在上层大气中的钠原子，以产生人造的“参考星”。这些钠“恒星”发出的光需要用来测量和校正湍流。为了设计这些系统，我们必须首先了解地球钠层的结构。通过将一个6米的液体反射镜望远镜与一个复杂的激光和探测器系统相结合，我的团队开发了一种钠激光雷达（激光雷达），可以产生无与伦比的数据质量。我和我的学生将利用这个设施来研究和更好地了解这个重要的大气区域的结构和动力学，并为超大型望远镜的发展提供必要的知识。

Future advances in our knowledge of the Universe will require new powerful telescopes on Earth and in space, with a resolution and sensitivity 10 to 100 times greater than present facilities. These telescopes, now being designed by astronomers and engineers worldwide, will achieve their power by a combination of large aperture and advanced technologies. One of these technologies, adaptive optics, is key to all future large ground-based telescopes because it can largely correct for the blurring effect of turbulence in the atmosphere. Next-generation AO systems will require high-powered lasers and sophisticated computer-controlled deformable mirrors. The lasers are used to illuminate sodium atoms, deposited by meteors in the upper atmosphere, in order to produce artificial "reference stars". The light from these sodium "stars" is needed to measure, and then correct for, the turbulence. To design these systems, we must first understand the structure of Earth's sodium layer. By combining a 6-metre liquid-mirror telescope with a sophisticated laser and detector system, my team has developed a sodium lidar (laser radar) that produces data of unsurpassed quality. My students and I will use this facility to study and better understand the structure and dynamics of this important region of the atmosphere, and provide knowledge essential for the development of extremely large telescopes.