| AVS 54th International Symposium | |
| Plasmonics Topical Conference | Monday Sessions |
| Session PL-MoA |
| Session: | Plasmon Dynamics and Magnetoplasmonics |
| Presenter: | A. Cebollada, IMM-CNM-CSIC, Spain |
| Authors: | A. Garcia-Martin, IMM-CNM-CSIC, Spain J.B. Gonzalez-Diaz, IMM-CNM-CSIC, Spain A. Cebollada, IMM-CNM-CSIC, Spain J.M. García-Martin, IMM-CNM-CSIC, Spain G. Armelles, IMM-CNM-CSIC, Spain M.U. González, ICFO, Spain G. Badenes, ICFO, Spain R. Quidant, ICFO, Spain |
| Correspondent: | Click to Email |
In the last years, plasmonics has consolidated as a powerful approach to obtain photonic devices with novel capabilities. To get this progress forward, important efforts are dedicated to developing active and/or externally controlled systems. Magnetic fields can influence the propagation of surface plasmon polaritons (SPP),1 so the mixing of magnetic and plasmonic materials seems a promising approach for obtaining these externally controlled systems. Up to now, multilayers of noble and magnetic metals have been analyzed and they have shown to present both plasmonic and magneto-optic (MO) effects. Moreover, the MO effect is enhanced in the presence of an excited plasmon in the system.2 In this work, we present the study of the MO and plasmonic activity in structures exhibiting both SPP and localized surface plasmons (LSP). The samples consist on a continuous Au/Co/Au trilayer deposited on glass by sputtering, covered with a dielectric spacer of SiO2 on top of which an array of Au nanodiscs (100 nm in diameter) have been fabricated by electron beam lithography. This system presents two kinds of surface plasmon resonances: The Au nanoparticles sustain LSP, and the trilayer/silica interface SPP, which can be excited by means of the Au nanoparticles grating. By controlling the parameters of the nanoparticles array, the relative positions of the two plasmon resonances of the system can be engineered.3 The trilayer also presents MO properties due to the presence of the Co layer. The MO properties of the system have been analyzed measuring the polar Kerr rotation and ellipticity spectra. The trilayer/nanoparticles system shows a different spectrum from that of the trilayer alone. In particular, an increase of the MO signal in the trilayer/nanoparticle spectra appears at the spectral position of the LSP. This increase depends on the coupling strength between the LSP and the SPP, which can be controlled by the periodicity of the array and the thickness of the dielectric spacer. These results open the door to the design of active magnetoplasmonic devices based on interacting localized and propagative surface plasmon modes.
1 B. Sepúlveda, L. M. Lechuga and G. Armelles, J. Lightwave Technol. 24, 945-955 (2006).
2 C. Hermann et al., Phys. Rev. B 64, 235422 (2001).
3 J. Cesario, R. Quidant, G. Badenes and S. Enoch, Opt. Lett. 30, 3404 (2005).