Wiener filter

Rana Adhikari explains how LIGO uses laser interferometry to detect tiny changes in space-time caused by gravitational waves. He describes how Fabry–Pérot cavities increase the light’s effective travel distance, and how laser noise, mirror motion, and environmental disturbances limit sensitivity. The talk covers LIGO’s engineering challenges, feedback control, and signal processing, including plans to use nonlinear methods to remove noise. Adhikari also discusses future detector designs, including space-based observatories and ways to improve how gravitational waves are converted into measurable signals.