A sodium laser guide star coupling efficiency measurement method

• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2016,（9）
• 页码范围: 95-100
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-4527/16/9/144

摘要

A large telescope's adaptive optics (AO) system requires one or more bright artificial laser guide stars to improve its sky coverage.The recent advent of a high power sodium laser is perfect for such application.However,besides the output power,other parameters of the laser also have a significant impact on the brightness of the generated sodium laser guide star,mostly in non-linear relationships.When tuning and optimizing these parameters it is necessary to tune based on a laser guide star generation performance metric.Although return photon fluxis widely used,variability of the atmosphere and sodium layer makes it difficult to compare results from different sites or even within a short time period for the same site.A new metric,coupling efficiency,is adopted in our field tests.In this paper,we will introduce our method for measuring the coupling efficiency of a 20W class pulse sodium laser for AO application during field tests that were conducted during 2013-2015.