Readout of the vibration of nanowires using fibre optics: Combining light scattering and the interference effect

Nanowires are good transducers to sense minute mechanical changes. A limitation in the mechanical motion detection of the nanowire is to identify the mode of vibration. In this work, we investigate the nano-optomechanical interaction between a nanowire and a focused Gaussian beam of light to analyze the vibration of nanowires. We combine effects of light scattering and light interference, across the optical axis and along the optical axis of the micro-lens fibre optic interferometer which is used in our study, respectively. Our analysis shows that the optimal detection sensitivity of the micro-lens fibre optic interferometer depends on both the vibration direction and diameter of the nanowire. Quantities which are of interest for experimentalist are analyzed, and our results could provide a guide for optical readout experiments of the vibration of nanowires.