LAUSR

An opto-electro-mechanical system formed by a nanomembrane capacitively coupled to an LC resonator and to an optical interferometer has been recently employed for the high--sensitive optical readout of rf signals [T. Bagci, \emph{et~al.}, Nature {\bf 507}, 81 (2013)]. Here we propose and experimentally demonstrate how the bandwidth of such kind of transducer can be increased by controlling the interference between two-electromechanical interaction pathways of a two--mode mechanical system. Using a $1 \times 1 mm$ SiN membrane coated with a $27 nm$ Nb film we achieve a sensitivity of $300 nV/\sqrt{Hz}$ over a bandwidth of 15 kHz, at room temperature.