Dresden 2011 – wissenschaftliches Programm
O 18.4: Vortrag
Montag, 14. März 2011, 18:00–18:15, PHY C213
Light Localization Effects in Commensurate Gratings — •Aude Barbara1,2, Jerôme Le Perchec3, Stéphane Collin4, Camille Maxime1,2, and Pascal Quémerais1,5 — 1Institut Néel, CNRS-UJF, Grenoble, France — 2IAPP, TU Dresden, Germany — 3CEA, Grenoble, France — 4LPN, Marcoussis, France — 5MPI-PKS, Dresden, Germany
We present a study in which infrared light localization phenomena are induced in commensurate gratings made of deep sub-wavelength metallic grooves. We combined the effects of light trapping within active sites (the deep cavities) with the properties of self-similar arrangements (commensurate gratings). We show that as the degree of commensuration tends to an irrational number new light localization states are produced. Interestingly, these have properties close to that reported for hot spots on disordered surfaces. In particular they present a very high sensitivity to the variation of the excitating field (wavelength and incident angle).
We also experimentally demonstrated the existence of these new resonances and measured their dispersion diagrams. We observed selective light localization within the cavities, transition from localized to delocalized modes and modifications of the mode coupling with the incident light leading to the generation of black modes. The theoretical analyze is in full agreement with the experiments.
A. Barbara et al. Opt. Exp. 16, 19127 (2008)
A. Barbara et al. Opt. Exp. 18, 14913 (2010)