  We present theoretical studies of the nature of the collective plasmon
resonances of surfaces upon which ordered lattices of spherical metallic
particles have been deposited. The collective plasmon modes, excited by light
incident on the surface, are explored for both square and rectangular lattices
of particles. The particular resonances excited by an incident beam of light
depend on the frequency, polarization, and angles of incidence. We show that
one can create surfaces for which the polarization of the reflected light is
frequency dependent. The form of the polarization dependent spectra can be
tuned by choosing materials and the parameters of the nanoparticle array.
