Numerical analysis of simultaneous measurement of the refractive index and the pressure utilizing the mode splitting in a single-opening microring resonator

作者：Zhang, Ping^*; Wang, Yufei; He, Dongyue^*; Xiao, Mi

来源：Optics Communications, 2019, 434: 167-174.

DOI：10.1016/j.optcom.2018.10.054

• Single-opening microring resonator (SOMRR)
• Mode splitting
• Dual-sensing
• Biosensing application
• Single-opening resonator (SOMRR)
• application

In this paper, a single-opening microring resonator (SOMRR) is proposed for simultaneous measurement of refractive index (RI) and pressure. The notch angle lifts the degeneracy of clockwise and counter-clockwise WGMs to excite the mode splitting, forming the symmetric and the asymmetric standing wave modes (SWMs) in the SOMRR. Due to the different electromagnetic field energy distribution of the two SWMs, the symmetric SWM and the asymmetric SWM show different sensitivities toward the change of ambient RI and the pressure exerted on the resonator. Through the three-dimensional FDTD simulations of the two SWMs under different external environments and loads, we obtain a RI sensitivity of 77.07 nm/RIU, a high pressure sensitivity of 5.01 pm/kPa for the symmetric SWM and a RI sensitivity of 69.54 nm/RIU, a high pressure sensitivity of 5.72 pm/kPa for the asymmetric SWM. Moreover, by solving the inverse matrix of the sensitivity matrix, the resonance wavelength shifts respectively caused by the change of RI and pressure can be distinguished. For the biosensing application based on the flexible photonic device, the effect of strain-optical coupling can be eliminated by using this method. It advances the accuracy of detection results and provides a novel route to achieve its application for biosensing in the real world.

• 出版日期2019-3-1
• 单位天津大学