A theoretical and experimental investigation into the enhancement of near electro-magnetic field via plasmonic effects

In this study, we use the finite-difference time-domain (FDTD) method and an attenuated-total-reflection (ATR) fluorescent optical microscope to investigate into the enhancement of near electro-magnetic (EM) field via plasmonic effects. In order to enhance the near EM field on the sensing surface, a metallic particle layer is added under the Kretschmann configuration of the conventional surface plasmon resonance sensor based on the ATR method. The affiliation by the simulation and experimental results can help us to understand the mechanisms of surface plasmons and particle plasmons on the sensor surface, and the effects of the EM field enhancement are classified as the surface plasmon effect, particle plasmon effect, interparticle coupling effect, and gap mode effect. By analyzing and comparing the results based on the FDTD method and the ATR fluorescent microscope, we can understand more about the plasmonic effects in order to deign a novel ultra-high resolution plasmonic biosensor.