Development of high power laser components and in situ contamination monitoring for future terrestrial GW detectors

This research award will enable 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 will be developed which can monitor mirror surface contaminants during the operation of Advanced LIGO using a nonlinear

optical technique known as surface second harmonic generation. Second, optical isolation of high power laser beams is important for Advanced LIGO, and this research will address issues with the development of optical isolators capable of handling higher laser powers.

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.