  We have studied the magneto-optical Kerr effect and optical reflectance of
perpendicular magnetized Co/Pt films on self-assembly two-dimensional
polystyrene spheres. It is shown that the magneto-optical and the reflectance
spectra are correlated to each other. Calculations have shown that the
magneto-optical Kerr rotation and the Kerr ellipticity spectra are governed by
the resonant coupling of light to the excitations of surface plasmon polaritons
and modified by the sphere diameters. These effects lead to the possibility of
developing new magnetoplasmonic nanosensors.
