Quartz Crystal Resonator Used as an Optical Fabry-Perot Cavity

The best plano-convex quartz crystals resonators can have quality factors up to a few billion at low temperature, which makes them interesting for ultrastable clocks. For this application, it's best they are optomechanically actuated. The first step towards this is to demonstrate they can be used as optical Fabry-Perot cavities with almost no change to their typical piezoelectric building. This paper is focused on the feasability of such optical use.