R. Robie

Low temperature mechanical dissipation of an ion-beam sputtered silica film

Thermal noise arising from mechanical dissipation in oxide mirror coatings is an important limit to the sensitivity of future gravitational wave detectors, optical atomic clocks and other precision measurement systems. Here, we present measurements of the temperature dependence of the mechanical dissipation of an ion-beam sputtered silica film between 10 and 300 K. A dissipation peak was observed at 20 K and the low temperature dissipation was found to have significantly different characteristics than observed for bulk silica and silica films deposited by alternative techniques. These results are important for better understanding the underlying mechanisms of mechanical dissipation, and thus thermal noise, in the most commonly-used reflective coatings for precision measurements.

Development of Ultra-low Optical and Mechanical Loss aSi Coatings Using Novel ECR Ion Beam Deposition

One of the significant limiting factors in gravitational wave detectors is the Brownian noise associated with the optical coatings [1], which are required to form the highly-reflective laser mirrors. UWS has a unique range of capabilities being used to help develop novel coating technology that can address this challenge, targeted for aLIGO+ and beyond.