Mechanical resonators constitute an essential element in emerging quantum technologies. Since such resonators can couple to a range of different degrees of freedom, they are particularly promising in interfacing disparate quantum systems. The recent developments in the design of mechanical resonators with ever decreasing dissipation and quantum-coherent optical control of their displacement has cemented them as a principal element in the toolbox of hybrid quantum systems.

In this thesis, we report the demonstration of a long-lived and efficient memory for light based on an optomechanical cavity, operating at a wavelength in the telecom C-band. We study the storage and retrieval of coherent fields at room temperature, and demonstrate long life-times and reasonable efficiencies, T1 ≈ 23 ms and η ≈ 40% respectively, converting optical information to mechanical excitations by the phenomenon of optomechanically induced transparency.

We extrapolate the demonstrated room-temperature performance to cryogenic conditions, with cautious estimates indicating the feasibility of ground state cooling and the associated quantum-coherent storage of light with less than one added noise quantum. Lastly, we show that modest improvements to our platform can enable observing the effects of injecting single photons, as a step towards quantum repeater applications.