High-Performance Refractive Index Sensing Based on Fano Resonances in a Subwavelength Grating Waveguide Microring Resonator

作者：Xinyu Li, Xinzhe Xiong, Yan Song, Shibo Sun, Yameng Xu, Li Shen · 发表于：Journal of Lightwave Technology · 年份：2025 · DOI：10.1109/jlt.2025.3569796 · 被引用次数：4 · 研究领域：Photonic and Optical Devices、Advanced Fiber Optic Sensors、Semiconductor Lasers and Optical Devices

High sensitivity and low detection limit are critical for refractive index (RI) sensors. This work introduces a subwavelength grating waveguide microring resonator (SWG-MRR) as a novel platform for achieving Fano resonances without relying on complex cascaded structures. By tracking the Fano resonance of the SWG-MRR, high-performance RI sensing is experimentally demonstrated with high sensitivity and low detection limit. Using the wavelength detection method, the sensitivity and detection limit are 460 nm/RIU and 4.35×10-5RIU, respectively. For the intensity detection approach, the sensitivity and detection limit are 2.05×104dB/RIU and 4.88×10-8RIU, respectively. This work presents an efficient scheme for realizing Fano resonances and highlights the SWG-MRR as a promising candidate for lab-on-chip sensing systems.