Advanced High-Performance Biochemical Sensor: Synchronous SPR Excitation with Parallel Multiple Single-Mode Fibers (SMFs)

This sensor utilizes conventional single-mode fiber (SMF) to create a refractive index (RI) surface plasmon resonance (SPR) system. To enhance its capabilities, multiple SMFs are employed in parallel, enabling the synchronous and collective activation of surface plasmon polaritons (SPPs) to achieve rapid responses for the detection of biochemical analytes in the infrared spectrum, ranging from 1200 to 6900 nm. The sensor’s characteristics are meticulously analyzed using the all-vector finite element method (FEM). The sensing medium comprises gold, chosen for its exceptional corrosion resistance and stability. Gold facilitates the efficient release of free electrons, promoting the coupling effect between the first-order x-odd mode and SPP mode, which is particularly prominent in this setup. The investigated sensor showcases remarkable performance metrics, which boasts an impressive maximum wavelength sensitivity of 70,000 nm/RIU, accompanied by an average sensitivity of 14,204.55 nm/RIU and an exceptional resolution reaching 1.43 × 10−6 RIU. Notably, this splendid performance is consistent across a wide RI range, spanning from 1.00 to 1.44. Additionally, the signal-to-noise ratio (SNR) and figure of merit (FOM) are exceptional, while the walk-off length of 205 m far exceeds the transmission distance of microstructure optical fibers (MOFs). In comparison to similar MOFs, this SMF-based sensor offers distinct advantages. Its simple structure, cost-effectiveness, and exceptional performance address manufacturing challenges and overcome existing technical limitations. This breakthrough technology holds the potential to revolutionize various fields, including environmental monitoring, biomedicine, and chemical analysis.