@Article{, title={Surface Plasmon Resonance (SPR) Simulation of a Gold-Bismuth Bi-layer Gas Sensor}, author={Ruqayah A. Ulwali and Heba Kh. Abbas and Ali J Karam and Ali A. Al-Zuky and Mahasin F. Hadi Al-Kadhemy and Anwar H. Al-Saleh}, journal={Iraqi Journal of Science المجلة العراقية للعلوم}, volume={63}, number={8}, pages={3402-3411}, year={2022}, abstract={The features of plasmonic surface frequency sensor technology, such as thesmall number of sensor samples required, electromagnetic interference, and highsensitivity, have been found to be highly important.. In this paper, a simulationprogram was created in Matlab_b2018 by adopting Fresnel equations for calculatingthe reflectivity of the electromagnetic wave between different media. A surfaceplasmon resonance sensor based on electromagnetic wavelengths within the range(100 nm to 1000 nm) has been proposed. The transfer matrix was used for a systemconsisting of four different media. The first medium is a semicircular BK7 glassprism, the second medium is a gold layer (40 nm thick), then a bismuth layer ofvariable thicknes(10–80) nm, and the last medium is air as the sensing medium. Thesurface plasmon resonance (SPR) technique was adopted based on the Kretschmannconfiguration in the simulation of the proposed system. The simulation resultsshowed that there is no SPR within the range of wavelengths (100-500nm), whileSPR appears in the visible region and in the IR region at wavelengths (900 and1000nm). The SPR phenomenon starts to weaken gradually with an increase in thethickness of the bismuth layer. The full width at half maximum (FWHM) decreaseswith the decrease of thickness of bismuth layer. The best value for it is (10) atthickness (d=10 nm) and wavelength (900 nm). While the height (H) of the SPR dipincreased, with the best value of (0.95) at thickness (d=10 nm) and wavelength (700nm). Also, the sensitivity increased with increasing the bismuth layer thickness atwavelengths (700 , 800,and 1000 ) nm. The highest obtained sensitivity(S) was (112.5 deg/RIU).

} }