Fano resonance-enhanced planar waveguide sensor utilizing MoS₂ for high-performance sensing application

Abstract

Sensing performance of a Fano resonance waveguide based sensor having a MoS2 material assisted with low refractive index coupling prism BK7 is analyzed. Position of MoS2 is optimized by considering two six-layer structural configurations i.e. PAMCFS and PMACFS and their results are compared at particular guiding layer thickness 500 nm and coupling layer thickness 700 nm. The reflectance formula of proposed six-layer waveguide is obtained using Fresnel’s equations. Our analysis shows that the PAMCFS waveguide gives better sensing performance than PMACFS. Further, sensing parameters is analyzed for different thickness of coupling layer and guiding layer. The maximum obtained sensitivity for zero order Fano resonance mode in intensity interrogation of the proposed PAMCFS waveguide structure is 6.847×106 a.u./RIU at guiding layer thickness 800 nm and coupling layer thickness 1000 nm. Also, at these thicknesses, FWHM is obtained in order of ~10-6 while the achieved detection accuracy and figure of merit in order of ~107 and ~106 respectively.