Highly sensitive surface plasmon resonance sensor based on the anti-resonant fiber with six nested tubes

On the heels of the continuous development of optical fiber sensing technology, optical fiber sensors based on surface plasmon resonance (SPR) have attracted widespread attention. Herein, an SPR sensor based on the six nested anti-resonant fiber (ARF) is designed and analyzed by the finite element method (FEM). All the structural parameters are optimized to achieve high-sensitivity liquid refractive index detection. Filling the anti-resonant tube with plasmonic materials to excite SPR can further reduce the manufacturing complexity. The optimal ARF-SPR sensor has excellent characteristics, including an average wavelength sensitivity of 42,000 nm/RIU, maximum sensor length of 0.08 cm, and resolution of 1.61×10^-6 <i>R</i> <i>I</i> <i>U</i>. The ARF-SPR sensor has great potential in chemical analysis, biomedicine, and other fields.