Advanced low loss PCF-based SPR sensor for enhanced sensor length configurations flexibility with exceptional superior sensing performance capability

Advanced low loss photonic crystal fibers (PCF) based Surface plasmon resonance (SPR) for the enhancement of the sensor length configurations flexibility is simulated with exceptional superior sensing performance capability. PCF-SPR sensors are widely recognized for their excellent light-guiding capabilities, making them highly suitable for precise biosensing applications. Enhancing sensitivity remains crucial, especially for applications demanding high accuracy, with confinement loss being a key factor influencing sensor performance. This paper presents an ultra-low-loss PCF-based SPR biosensor, designed for high-sensitivity refractive index (RI) detection in the range of 1.30 to 1.42. Using advanced Finite Element Method (FEM) simulations, the sensor achieves a wavelength sensitivity (WS) of 11,000 nm/RIU, amplitude sensitivity (AS) of 1,524 RIU^− 1, and a figure of merit (FOM) of 275. Its single-core structure improves light confinement and analyte interaction, contributing to a remarkably low propagation loss of 0.00077 dB/cm. This enables adaptable sensor lengths without sacrificing performance, making it ideal for practical applications. With its robust design, high sensitivity, and low loss, the proposed biosensor is well-suited for a variety of bio-detection applications, including basic medical diagnostics and food safety analysis.