Photoemission spectra are calculated for thin films of Ag on Au(111) u
sing the method of Green's function matching. For very low photon ener
gies (omega less than or similar to 10 eV) the peak intensities of the
thin film states oscillate with the film thickness. These oscillation
s are caused by the relaxation of the k(perpendicular to)-conservation
of the optical excitation in photoemission.