Development of High Power Continuous Wave Lasers, Components, and Optical Contamination Diagnostics for Future Ground-based Gravitational Wave Detectors

该研究奖将使先进激光干涉仪引力波天文台（Advanced LIGO）的重要研究得以继续。首先，镜面的质量对Advanced LIGO的性能至关重要。一种方法正在开发中，以监测镜面污染物的操作过程中，先进的LIGO使用的非线性光学技术称为表面二次谐波产生（SSHG）。从多层介电涂层和SSHG的实验研究，特别是先进的LIGO中使用的超抛光镜的控制污染的调查，SSHG产生的理论研究将进行。其次，高功率激光束的光学隔离对于先进LIGO是重要的，并且本研究解决了能够处理更高激光功率的光学（法拉第）隔离器的发展问题。要进行的活动是表征热去极化，隔离比，和热透镜的大口径法拉第隔离器的设计和测试先进的LIGO法拉第隔离器在真空中。
&先进的LIGO将打开一个新的天文学窗口--通过引力波的发射探测宇宙中一些最灾难性事件的能力，这是阿尔伯特·爱因斯坦近100年前提出的一种机制，但尚未被直接观察到。这些研究将有助于Advanced LIGO在长时间范围内的运行，并可能在运行后提高其性能。它们还将影响许多使用高功率激光器的应用。最后，这项研究还将促进国际合作。

This research award will enable the continuation of investigations important to the Advanced Laser Interferometer Gravitational-wave Observatory (Advanced LIGO). First, the quality of the mirror surfaces is crucial to the performance of Advanced LIGO. A method is under development to monitor mirror surface contaminants during the operation of Advanced LIGO using a nonlinear optical technique known as surface second harmonic generation (SSHG). Theoretical investigation of SSHG generation from multi-layer dielectric coatings and experimental investigation of SSHG, specifically investigations of controlled contamination on superpolished mirrors used in Advanced LIGO, will be conducted. Second, optical isolation of high power laser beams is important for Advanced LIGO, and this research addresses issues with the development of optical (Faraday) isolators capable of handling higher laser powers. Activities to be undertaken are characterization of thermal depolarization, isolation ratio, and thermal lensing for a large aperture Faraday isolator design and testing of Advanced LIGO Faraday isolators in vacuum.

Advanced LIGO will open a new astronomical window --- the ability to probe some of the most cataclysmic events in universe through the emission of gravitational waves, a mechanism proposed by Albert Einstein almost 100 years ago, but yet to be directly observed. These investigations will both aid in the operation of Advanced LIGO over long time scales and potentially improve its performance once it is in operation. They will also impact many applications which use high power lasers. Finally, this research will also foster international collaborations.