Thermal noise and material issues for gravitational wave detectors

Thermal noise forms an important limit to the sensitivity of km-scale interferometric detectors searching for gravitational waves from astrophysical sources. The importance of quantifying and reducing the thermal noise in the mirrors of these detectors has motivated considerable progress in recent years, both theoretically and experimentally, in understanding how thermal noise in mechanical systems appears when sensed optically. Here we present a summary of recent progress in the field and discuss some of our current work aimed at developing low noise suspensions for future gravitational wave detectors.