Surface profile dependence of the photon coupling efficiency and enhanced fluorescence in the grating-coupled surface plasmon resonance

摘要

The fluorescence excited by the enhanced electric field of grating-coupled surface plasmon resonance was detected on biochips. The enhancement of the electric field on a metallic grating surface was calculated using the finite difference time domain method for rectangular, trapezoidal, and sinusoidal models to clarify the grating-surface profile dependence of the enhanced fluorescence. The computational results showed that the enhancement in the trapezoidal model was stronger than that in the other models, and that the groove depth dependence of the enhancement in the trapezoidal model agreed well with the experimental data. The grating surface profile, including the groove depth, was found to bean important parameter of the grating structure for it to couple effectively with light.