Niloy Sutra Dhar, Md Rejvi Kaysir, Sumit Paul, Md Jahirul Islam
This study proposes and optimizes a novel, highly sensitive suspended core fiber (SCF)-based Surface Plasmon Resonance (SPR) sensor that supports both conventional confinement loss (CL) peak and lower birefringence peak interrogation methods. Three key design parameters, including the thickness of the plasmonic layer, its separation from the core, and the width of the plasmonic layer, are optimized using the Taguchi L9 (33) orthogonal array. Numerical analysis using the finite element method (FEM) is performed to evaluate the sensor’s performance. Under the confinement loss peak method, the sensor achieves peak wavelength sensitivities of 120,000 nm/RIU and 40,000 nm/RIU for the x- and y-polarized modes, respectively. Using the lower birefringence peak method, the sensor achieves a maximum wavelength sensitivity of 150,000 nm/RIU and a minimum resolution of 6.67 × 10–7 RIU. The sensitivity and selectivity of the proposed sensor are significantly improved as the two methods are employed for sensing purposes. The proposed sensor operates across a wide refractive index (RI) range (1.00–1.44) and exhibits exceptional performance under dual interrogation schemes, making it highly suitable for precise, real-time chemical and biomedical sensing.