Theoretical analysis of the propagation of surface plasmon waves in multilayer surface plasmon resonance biosensor

Abstract

The performance of a surface plamon resonance biosensor (SPRB) is directly linked to the excitation and the nature of propagation of surface plasmon (SP) waves. The excitation and propagation of SP wave in further depends on the geometry of the device and type of excitation (e.g., grating coupled, prism coupled etc.). This paper presents the investigation of surface plamon waves in conventional and multilayer SPRB. The multilayer structure of SPRB includes graphene based multilayer SPRB which consists a number of graphene layer on top of gold layer. The propagations of SPs, electric and magnetic field distributions are studied for various conditions. Absolute magnitudes of electric and magnetic field along with their direction are studied. It was found that the strong plasmon is caused on the sensing interface when a resonance is occurred and on the other hand a weak plasmon is formed while resonance is not established in which case most of the field is reflected back to the medium of incidence. It was also validated that SP waves are generated if the polarization of the field is in parallel to the plane of incident. The numerical simulation confirmed that the propagation of SP wave progressed as the phase advanced and then decayed from its highest oscillation after a certain phase value.