  A broadband detection method with coherent laser pulses exciting surface
plasmons is investigated. The intensity and phase characteristics of the
reflected light in Kretschmann configuration are calculated. It is shown that
by mixing in-plane and out-of-plain polarization components of the incident
light, the measurements of the changes of the refractive index of the adjacent
media can be efficiently performed by observing the shift of the steep slope of
the surface plasmon resonance (SPR) reflectance curve. We have demonstrated
that such sensing can be performed by observing the angular shift of the SPR
curve as well as the spectral shift. The developed model can account for an
arbitrary number of layers and is used to simulate the response when an
additional functionalizing layer adjacent to the gold film is used.
