Displacement Detection Of Silicon Nanowires By Polarization-enhanced Fiber-optic Interferometry

摘要

We describe the displacement detection of freestanding silicon [111] nanowires by fiber-optic interferometry. We observe approximately a 50-fold enhancement in the scattered intensity for nanowires 40-60 nm in diameter for incident light polarized parallel to the nanowire axis, as compared to perpendicular polarization. This enhancement enables us to achieve a displacement sensitivity of 0.5 pm/ Hz~(1/2) for 15 μW of light incident on the nanowire. The nanowires exhibit ultralow mechanical dissipation in the range of (2×10~(-15))-(2×10~(-14)) kg/s and could be used as mechanical sensors for ultrasensitive scanning probe force measurements.