Magneto-optical polar and longitudunal Kerr effects in bcc-Fe (001) epitaxial films sandwiched between Au (001) layers were studied for Fe thicknesses dFe = 3-1000Å in the photon energy range of 1.55-6.2 eV. The polar Kerr rotation peaks related to quantum well states (QWS) fomed in Fe layer disappeared above dFe=20Å. In films with dFe≥100Å, the polar Kerr spectra above 3.5 eV were substantially the same as the spectrum of bulk Fe. Below 3 eV, on the other hand, a Kerr rotation peak enhanced by the plasma edge of Au at 2.5 eV shifted to the lower energy side with the increase of dFe even above 100Å, and the intensity of the pear exceeded the bulk value around dFe = 100Å. In the longitudinal Kerr rotation spectra the peaks related to QWS appeared nowhere in the whole range of dFe. This suggests that the contribution of QWS to the off-diagonal complex dielectric tensor element responsible for longitudinal Kerr effect is in our Fe films negligible.
