Optical Fabry-Perot-type microcavities are miniaturized devices in which light is stored by trapping it between two mirror surfaces. Typical sizes for these devices range from some hundred micrometer down to the wavelength of the light. When the light bounces between the opposing mirrors, it can interact with the medium within the cavity volume. The repeated reflections amplify this effect by allowing each quantum of light - each photon - to experience this  interaction many times. Depending on the quality of the microcavity a photon is reflected many thousand times before eventually leaving the cavity through one of the mirrors. Making these cavities small further boosts the mutual effect of the confined light mode and the system in the cavity. 

In our group we work with fiber-based Fabry-Perot cavities (FFPCs) that we both use to interface mechanical resonators and that we further develop and  integrate into sensing experiments.  

Mechanical Metamaterials are artificial systems that use structuring of a material in order to shape its mechanical properties. This enables to engineer the localization of vibrations, how they are guided, and how they can be interfaced using light fields, or how they themself can serve  as an interface to other on-chip structures.  

We use this to create mechanical devices that trap and guide vibration in thin dielectric films that together with optical microcavities can serve as opto-mechanical circuits or optically modified materials.