Real-time hybrid angular-interrogation surface plasmon resonance sensor in the near-infrared region for wide dynamic range refractive index sensing
Hidenori Koresawa, Kota Seki, Kenji Nishimoto, Eiji Hase, Yu Tokizane, Taka‐aki Yano, Taira Kajisa, Takeo Minamikawa, Takeshi Yasui
Abstract
Abstract Herein, we integrated angle-scanning surface plasmon resonance (SPR) and angle-fixed SPR as a hybrid angular-interrogation SPR to enhance the sensing performance. Galvanometer-mirror-based beam angle scanning achieves a 100-Hz acquisition rate of both the angular SPR reflectance spectrum and the angle-fixed SPR reflectance, whereas the use of near-infrared light enhances the refractive index (RI) sensitivity, range, and precision compared with visible light. Simultaneous measurement of the angular SPR reflectance spectrum and angle-fixed SPR reflectance boosts the RI change range, RI resolution, and RI accuracy to 10 –1 –10 –6 RIU, 2.24 × 10 −6 RIU, and 5.22 × 10 −6 RIU, respectively. The proposed hybrid SPR is a powerful tool for wide-dynamic-range RI sensing with various applications.