Consani Cristina, Dubois Florian, Auböck Gerald
Opt Express. 2021 Mar 29;29(7):9723-9736. doi: 10.1364/OE.415825.
Proper optimization of a photonic structure for sensing applications is of extreme importance for integrated sensor design. Here we discuss on the definition of suitable parameters to determine the impact of photonic structure designs for evanescent-wave absorption sensors on the achievable resolution and sensitivity. In particular, we analyze the most widespread quantities used to classify photonic structures in the context of sensing, namely the evanescent-field ratio (or evanescent power factor) and the confinement factor Γ. We show that, somewhat counterintuitively, the confinement factor is the only parameter that can reliably describe the absorption of the evanescent-field in the surrounding medium, and, by quantifying the discrepancy between the two parameters for a set of realistic photonic structures, we demonstrate that using the evanescent-field ratio can lead to a wrong classification of the performance of different structures for absorption sensing. We finally discuss the most convenient simulation strategies to retrieve the confinement factor by FEM simulations.
对于集成传感器设计而言，为传感应用对光子结构进行适当优化至关重要。在此，我们讨论确定光子结构设计对倏逝波吸收传感器可实现的分辨率和灵敏度影响的合适参数的定义。特别是，我们分析了在传感背景下用于对光子结构进行分类的最普遍的量，即倏逝场比率（或倏逝功率因子）和限制因子Γ。我们表明，有点违反直觉的是，限制因子是唯一能够可靠描述周围介质中倏逝场吸收的参数，并且通过量化一组实际光子结构的这两个参数之间的差异，我们证明使用倏逝场比率可能会导致对不同结构吸收传感性能的错误分类。我们最后讨论通过有限元模拟检索限制因子的最便捷模拟策略。
