Interference-based multimode opto-electro-mechanical transducers

As recently demonstrated [T. Bagci, et al., Nature 507, 81 (2013)], an opto-electro-mechanical system formed by a nanomembrane, capacitively coupled to an LC resonator and to an optical interferometer, may be employed for the high{sensitive optical readout of rf signals. Here we show through a proof of principle device how the bandwidth of such kind of transducer can be increased by controlling the interference between the electromechanical interaction pathways of a two{mode mechanical system. The transducer reaches a sensitivity of 10 nV=Hz 1/2 over a bandwidth of 5 kHz and a broader band sensitivity of 300 nV=Hz 1/2 over a bandwidth of 15 kHz. We discuss strategies for improving the performance of the device, showing that, for the same given sensitivity, a mechanical multi-mode transducer can achieve a bandwidth significantly larger than that of a single-mode one.