Mid-infrared water pollutant sensor based on SPR-PCF

Abstract In this paper, a highly sensitive water pollutant optical sensor is proposed and analyzed. The suggested consists of photonic crystal fiber with core surrounded by four elliptical holes infiltrated the studied analyte (pure/polluted sample). addition, two gold nanorods are mounted horizontally at inner surfaces horizontal holes. can efficiently detect dissolved pollutants in such as nitric acid ( $${\mathrm{HNO}}_{3}$$ HNO 3 ) concentrations 14, 23 35% $${\mathrm{H}}_{2}{\mathrm{O}}_{2}$$ H 2 O 7, 15 30%. (analyte) have refractive indices (RIs) range 1.350–1.355 mid infrared regime from λ = 2200 nm to 3500 nm. A fully vectorial finite element method (FVFEM) employed for modal analysis reported structure. geometrical parameters maximize RI sensitivity where high 36,000 nm/RIU achieved between RIs 1.350 1.355. obtained higher than those recent sensors literature especially operating wavelengths.