Reported is on the observation of surface plasmon resonances showing s
harp maxima in the reflectivity of transverse magnetic visible radiati
on. Two systems of thin layers are examined, a bilayer of vanadium/gol
d, and a trilayer of iron/magnesiumfluoride/silver. Theoretical reflec
tivity data derived from Fresnel equations have been fitted to our exp
erimental data in order to find the optical constants and layer thickn
esses of the two systems. These parameters have then been used to mode
l the optical field profiles, thus illustrating the nature of the surf
ace plasmon resonances associated with the observed reflectivity maxim
a. Further, the potential of this type of surface plasmon resonance fo
r sensing applications is investigated.