Keck II laser guide star AO system and performance with the TOPTICA/MPBC laser
Keck II laser guide star AO system and performance with the TOPTICA/MPBC laser
复制标题
Keck II 激光导星 AO 系统和 TOPTICA/MPBC 激光器的性能
DOI：
--
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
K. Wei
中科院分区：
文献类型：
--
作者：
J. Chin;P. Wizinowich;E. Wetherell;S. Lilley;S. Cetre;S. Ragland;D. Medeiros;K. Tsubota;G. Doppmann;A. Otarola;K. Wei
Keck II激光制导星星（LGS）自适应光学（AO）系统于2015年12月从染料激光器升级为TOPTICA/MPBC拉曼光纤放大（RFA）激光器。世贸M.凯克天文台（WMKO）自2004年以来一直在使用第一代15 W染料激光器运行其AO系统。采用最新的二极管泵浦激光技术、拉曼放大和调谐良好的二次谐波发生器（SHG），这款下一代激光器（NGL）能够产生具有所需功率、波长和模式质量的高度稳定的589 nm激光束。光束的线性偏振和连续波格式沿着与光学回抽运被设计为提高钠原子耦合效率比以前操作的钠波长激光器。新激光器的效率和可操作性也得到了提高，降低了所需的输入功率和冷却，尺寸以及操作和维护它的人力。新激光器已安装在望远镜的仰角环上，其电子设备安装在新的Nasmyth子平台上，能够支持多达三个激光系统以供未来升级。激光从望远镜的次镜后面投射，使用最近实施的中心发射系统（CLS）来减小LGS光斑尺寸。我们将介绍新的激光系统和它的性能方面的功率，稳定性，波长，光斑大小，光学再泵浦，偏振，效率，和它的回报相对于指向对准磁场。初步LGSAO性能与系统返回到科学操作。我们还将提供WMKO当前和未来升级的最新信息。
The Keck II Laser Guide Star (LGS) Adaptive Optics (AO) System was upgraded from a dye laser to a TOPTICA/MPBC Raman-Fibre Amplification (RFA) laser in December 2015. The W. M. Keck Observatory (WMKO) has been operating its AO system with a LGS for science since 2004 using a first generation 15 W dye laser. Using the latest diode pump laser technology, Raman amplification, and a well-tuned second harmonic generator (SHG), this Next Generation Laser (NGL) is able to produce a highly stable 589 nm laser beam with the required power, wavelength and mode quality. The beam’s linear polarization and continuous wave format along with optical back pumping are designed to improve the sodium atom coupling efficiency over previously operated sodium-wavelength lasers. The efficiency and operability of the new laser has also been improved by reducing its required input power and cooling, size, and the manpower to operate and maintain it. The new laser has been implemented on the telescope’s elevation ring with its electronics installed on a new Nasmyth sub-platform, with the capacity to support up to three laser systems for future upgrades. The laser is projected from behind the telescope’s secondary mirror using the recently implemented center launch system (CLS) to reduce LGS spot size. We will present the new laser system and its performance with respect to power, stability, wavelength, spot size, optical repumping, polarization, efficiency, and its return with respect to pointing alignment to the magnetic field. Preliminary LGSAO performance is presented with the system returning to science operations. We will also provide an update on current and future upgrades at the WMKO.