Advances in Grating-Coupled Hybrid Surface Plasmon Resonance at Flat Metal-Analyte Interface

F. Haddada, A. Cherifib, M. Nedjaric, B. Bouhafsd, A. Bezzad aDepartment of Material Science, Science and Technology Faculty, University of Amenokal Hadj Moussa Ag Akhamouk, Tamanrasset 11000, Algeria bDepartment of Physics, Faculty of Exact Sciences and Informatics, Hassiba Benbouali University of Chlef, Chlef 02000, Algeria cLaboratory of Materials and Reactive Systems, Djillali Liabes University, Sidi Bel Abbes 22000, Algeria dTheoretical Physics Laboratory, Faculty of Sciences, University of Tlemcen, Tlemcen 13000, Algeria

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In this paper, we theoretically investigate the sensing characteristics of a metallic grating-coupled surface plasmon resonance sensor with the objective of showing their influence on the grating parameters. For comparison, the optical responses of silver (Ag), gold (Au), and copper (Cu), as plasmonic material layers, are separately adopted in the Kretschamann approach. The reflectivity of each plasmonic layer coated on top of a glass prism is analyzed using the wavelength interrogation method. The optical responses of the considered configurations are analyzed, where the impact parameters are related to the grating parameters (height, width, and periodicity) and layer thickness that have been suitably optimized. Additionally, the excitation angle of incident light is fixed in the range from 26° to 66°, and the outer medium refractive index is assumed in the range from 1.33 to 1.34. Thus, the obtained results reveal that the proposed structures allow for a remarkable coupling between surface plasmon resonance and localized surface plasmon resonance, whose functionality as efficient refractive index sensors is characterized by improved wavelength sensitivity in the range λ ≃ 400-100 nm, high figure of merit, and the narrowest spectral full width at half maximum of the resonant plasmonic response. Such preferential limits of the performance parameters should make the suggested multilayer approaches based on Ag, Au, and Cu a suitable choice for detection applications.

DOI:10.12693/APhysPolA.147.90 topics: surface plasmon resonance (SPR), metallic grating, wavelength interrogation method, refractive index (RI) sensor