Tunable linear and quadratic optomechanical coupling for a tilted membrane within an optical cavity: theory and experiment

Understand

We present an experimental study of an optomechanical system formed by a vibrating thin semi-transparent membrane within a high-finesse optical cavity.

• We show that the coupling between the optical cavity modes and the vibrational modes of the membrane can be tuned by varying the membrane position and orientation.
• In particular we demonstrate a large quadratic dispersive optomechanical coupling in correspondence with avoided crossings between optical cavity modes weakly coupled by scattering at the membrane surface.
• The experimental results are well explained by a first order perturbation treatment of the cavity eigenmodes.