Nonlinear optical effects in the LIGO gravitational-wave interferometer

摘要

LIGO (Laser Interferometer Gravitational-wave Observatory) is a trio of sensitive Michelson interferometers designed to detect extremely relativistic astrophysical processes by the ripples they produce in spacetime. For best sensitivity, these interferometers are kilometers long, contain nearly unstable cavities, and operate at high optical power, making them uniquely susceptible to thermal aberrations and radiation-pressure-derived instabilities. We describe the LIGO interferometers, and their high power lasers and input optics, and described how thermal aberrations have been successfully controlled using adaptive corrective heating. The Advanced LIGO detectors, an upgrade to LIGO planned for installation in the year 2010, will operate with even higher optical power. We detail the additional challenges in construction and thermal compensation for Advanced LIGO, and detail how radiation-pressure derived instabilities influence the design, operation, and sensitivity of Advanced LIGO.