Zhang Ping, Zhang Chen, Yan Zhiruo
Appl Opt. 2021 Apr 10;60(11):2958-2966. doi: 10.1364/AO.417669.
Concentric triple microring resonators with a single opening on the flexible SU-8 substrate are proposed and theoretically demonstrated for simultaneous detection of refractive index (RI) and pressure changes. Since an opening defect is introduced, the mode splitting occurs, which forms a symmetric and an asymmetric standing wave mode (SWM). The energy distribution of the two SWMs is quite different so that the sensitivities of the RI and pressure in the SWMs can be distinguished. The RI sensitivities of 186.37 nm/RIU and 107.69 nm/RIU and the pressure sensitivities of 1.42 pm/KPa and 1.07 pm/KPa are obtained corresponding to the symmetric and the asymmetric SWMs, respectively. By solving a second-order sensitivity inverse matrix, the change in RI and pressure can be measured simultaneously, thereby eliminating the influence of the strain-optical coupling effect in the field of biosensing application. The proposed structure has great potential in achieving simultaneous measurement of multiple parameters.
提出了一种在柔性SU-8衬底上具有单个开口的同心三微环谐振器，并从理论上证明了其可同时检测折射率（RI）和压力变化。由于引入了开口缺陷，发生了模式分裂，形成了一个对称和一个非对称驻波模式（SWM）。两种SWM的能量分布有很大差异，因此可以区分SWM中RI和压力的灵敏度。分别对应于对称和非对称SWM，获得了186.37 nm/RIU和107.69 nm/RIU的RI灵敏度以及1.42 pm/KPa和1.07 pm/KPa的压力灵敏度。通过求解二阶灵敏度逆矩阵，可以同时测量RI和压力的变化，从而消除生物传感应用领域中应变光耦合效应的影响。所提出的结构在实现多参数同时测量方面具有很大潜力。
