Theoretical assessment of D-shaped optical fiber chemical sensor associated with nanoscale silver strip operating in near-infrared region

In present work, we propose a surface plasmon resonance based D-shaped fiber for the chemical sensor using nanoscale silver strip deposited over polished surface of single mode fiber. Various parameters of the designed sensors are optimized to achieve the maximum wavelength sensitivity. The sensing properties are investigated using finite element method based on COMSOL Multiphysics. An average wavelength sensitivity of 2100 nm/RIU is obtained for wide range of refractive index (RI) varying between 1.34 and 1.42 and a maximum wavelength and amplitude sensitivity of 3240 nm/RIU and 192 RIU−1 is achieved for RI range varying between 1.38 and 1.42 with 3.08 × 10−5 RIU resolution. The results indicate that our designed sensor perform effectively in high RI range and hence can be used in chemical and biological sensing.