Non linear optics and magneto-optics in ultrathin metallic films

Ultrathin magnetic cobalt-based AurCorAu trilayers have been studied by optical second harmonic generation SHG. and by linear magneto-optical Kerr effect MOKE.. We show that SHG has a selective interface and surface sensitivity, whereas MOKE is bulk sensitive. SHG was used to probe the surface plasmon SP. resonance in AurCorAu films. The resonant coupling of SPs with SHG results in an enhancement and sign reversal of the non linear magneto-optical effects. On simple gold surfaces, we also demonstrate the existence of a strong relation between SHG and roughness measured by atomic force microscopy AFM.. q2000 Elsevier Science B.V. All rights reserved.