Improving the Dilution Factor in Loss Angle Measurements of Optical Coatings Used in Gravitational Wave Detection

Thermal noise due to the interaction of optical coatings with their environment is a fundamental source of noise in the current generation of gravitational wave detectors. It is crucial to accurately identify future materials and/or coating methods that possess the largest possible mechanical quality factor (Q). Current methods to find the Q of optical coating candidates suffer in precision due to depositing them onto thick substrates that store a large portion of energy during the measurement. We propose a new experimental approach that will more precisely measure the Q of coatings by depositing them onto 100 nm Silicon Nitride membranes.