Department of Electronic Engineering, National Taiwan University of Science and Technology, No.43, Sec. 4, Keelung Rd., Taipei 10607, Taiwan.
Sensors (Basel). 2014 Jan 10;14(1):1184-94. doi: 10.3390/s140101184.
Optical low-coherence interferometry (OLCI) takes advantage of the variation in refractive index in silicon-wire microring resonator (MRR) effective lengths to perform glucose biosensing using MRR interferograms. The MRR quality factor (Q), proportional to the effective length, could be improved using the silicon-wire propagation loss and coupling ratio from the MRR coupler. Our study showed that multimode interference (MMI) performed well in broad band response, but the splitting ratio drifted to 75/25 due to the stress issue. The glucose sensing sensitivity demonstrated 0.00279 meter per refractive-index-unit (RIU) with a Q factor of ~30,000 under transverse electric polarization. The 1,310 nm DFB laser was built in the OLCI system as the optical ruler achieving 655 nm characterization accuracy. The lowest sensing limitation was therefore 2 × 10-4 RIU. Moreover, the MRR effective length from the glucose sensitivity could be utilized to experimentally demonstrate the silicon wire effective refractive index with a width of 0.45 mm and height of 0.26 mm.
光学低相干干涉测量法（OLCI）利用硅线微环谐振器（MRR）有效长度的折射率变化来进行葡萄糖生物传感，使用 MRR 干涉图。MRR 的品质因数（Q）与有效长度成正比，可通过硅线传播损耗和 MRR 耦合器的耦合比来提高。我们的研究表明，多模干涉（MMI）在宽带响应中表现良好，但由于应力问题，分光比漂移至 75/25。在横向电场偏振下，葡萄糖传感灵敏度为 0.00279 米每折射率单位（RIU），品质因数（Q）约为 30,000。1310nm DFB 激光被构建在 OLCI 系统中作为光学标尺，实现了 655nm 的特征精度。因此，最低的传感限制为 2×10-4 RIU。此外，还可以利用葡萄糖灵敏度的 MRR 有效长度来实验证明硅线的有效折射率，硅线的宽度为 0.45mm，高度为 0.26mm。
