We describe an optical transduction mechanism to measure the flexural mode vibrations of vertically aligned nanowires on a flat substrate with high sensitivity, linearity, and ease of implementation. We demonstrate that the light reflected from the substrate when a laser beam strikes it parallel to the nanowires is modulated proportionally to their vibration, so that measuring such modulation provides a highly efficient resonance readout. This mechanism is applicable to single nanowires or arrays without specific requirements regarding their geometry or array pattern, and no fabrication process besides the nanowire generation is required. We show how to optimize the performance of this mechanism by characterizing the split flexural modes of vertical silicon nanowires in their full dynamic range and up to the fifth mode order. The presented transduction approach is relevant for any application of nanowire resonators, particularly for integrating nanomechanical sensing in functional substrates based on vertical nanowires for biological applications.

中文翻译：

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垂直纳米线谐振器的光传导

我们描述了一种光学传感机制，可以测量具有高灵敏度，线性度和易于实施性的，在平面基板上垂直排列的纳米线的弯曲模式振动。我们证明，当激光束平行于纳米线撞击基板时，从基板反射的光与它们的振动成比例地进行调制，因此测量此类调制可提供高效的共振读数。该机制适用于单个纳米线或阵列，对它们的几何形状或阵列图案没有特殊要求，并且除了纳米线的产生之外，不需要任何制造过程。我们展示了如何通过表征垂直硅纳米线在其整个动态范围内以及高达第五阶模级的分裂弯曲模式来优化该机制的性能。