Seismic isolation of Advanced LIGO: Review of strategy, instrumentation and performance

TL;DR

This paper reviews the seismic isolation strategies and instrumentation used in Advanced LIGO, highlighting a decade of research, recent performance achievements, and future prospects for improving gravitational wave detection sensitivity.

Contribution

It provides a comprehensive review of active seismic isolation techniques, instrumentation, and performance in Advanced LIGO, offering guidelines applicable to other sensitive ground-based experiments.

Findings

Achieved significant seismic isolation performance in Advanced LIGO.

Reviewed over a decade of active isolation research and development.

Discussed future improvements and their impact on gravitational wave detection.

Abstract

Isolating ground-based interferometric gravitational wave observatories from environmental disturbances is one of the great challenges of the advanced detector era. In order to directly observe gravitational waves, the detector components and test masses must be highly inertially decoupled from the ground motion not only to sense the faint strain of space-time induced by gravitational waves, but also to maintain the resonance of the very sensitive 4 km interferometers. This article presents the seismic isolation instrumentation and strategy developed for Advanced LIGO interferometers. It reviews over a decade of research on active isolation in the context of gravitational wave detection, and presents the performance recently achieved with the Advanced LIGO observatory. Lastly, it discusses prospects for future developments in active seismic isolation and the anticipated benefits to astrophysical gravitational wave searches. Beyond gravitational wave research, the goal of this article is to provide detailed isolation strategy guidelines for sensitive ground-based physics experiments that may benefit from similar levels of inertial isolation.