Sensing displacements at the nanoscale is the basis for many metrology applications, in particular atomic-force microscopy. Displacement sensing with nano-optomechanical structures provides interesting opportunities for integration, but it typically features a small dynamic range due to the near-field nature of the sensor-sample interaction. Here, a far-field sensing approach based on a grating coupler is considered and an analytical model used to tune its performance is introduced. The proposed model allows exploiting the full range of design parameters and thereby optimizing resolution and dynamic range. The compact size of the sensor and the possibility of integrating it with an on-chip laser and detector make it very promising for fully-integrated optical sensing systems.

中文翻译：

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对基于光栅耦合器的干涉仪进行建模以实现纳米级位移的远场传感

纳米级的位移是许多计量学应用的基础，尤其是原子力显微镜。具有纳米光学机械结构的位移传感为集成提供了有趣的机会，但是由于传感器-样品相互作用的近场性质，它通常具有较小的动态范围。在这里，考虑了基于光栅耦合器的远场传感方法，并介绍了用于调整其性能的分析模型。提出的模型允许利用设计参数的全部范围，从而优化分辨率和动态范围。传感器的紧凑尺寸以及将其与片上激光器和检测器集成在一起的可能性，使其对于完全集成的光学传感系统非常有前途。