A novel refractometric sensor based on optofluidic integration of composite core photonic crystal fibers

Abstract

We propose and demonstrate a novel refractometric sensor based on optofluidic technology in photonic crystal fibers with a composite core. The composite core consisting of a ring-like fluid channel around the refractive index matching core is architected within photonic crystal fibers. A different refractive index of water-like analyte is filled into the same channel in turn to form steady microflows around the matching core, and the refractive index of analyte can be detected by observing the resonant coupling between the composite and solid-core modes. The sensitivity of water-like analyte around 1.33 is about −1.11 × 103 nm per refractive index unit. Simulations indicate that analyte refractive index sensing possesses a dynamic range of 1 to 1.4. We also analyze the matching core with different refractive indices and optimize the structure. Since this kind of refractomeric sensor can be reused with high sensitivity by controlling the refractive index of matching core at different temperatures, it is a good candidate for bio-sensing.