IJMOT-2014-1-545 © 2014 IAMOT INTERNATIONAL JOURNAL OF MICROWAVE AND OPTICAL TECHNOLOGY, VOL.9, NO.1, JANUARY 2014 101 Magneto-optical Sandwiches for Surface Plasmon Resonance Systems Jaromír Pištora 1 *, Jaroslav Vlček 2 , Michal Lesňák 1 and Michael Čada 3 1 Nanotechnology Centre, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava-Poruba, Czech Republic 2 Department of Mathematics, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava-Poruba, Czech Republic 3 Department of Electrical and Computer Engineering, Dalhousie University Sexton Campus, P.O. Box 1000 Halifax, Nova Scotia, B3J 2X4 Canada Tel: +420 597323129; Fax: +420 597323139; E-mail: jaromir.pistora@vsb.cz Abstract - The Au/Fe grating/Au sandwiches located on BK-7 substrate have been applied in Otto configuration for magneto-optical (MO) surface plasmon resonance sensor units. We analyzed the reflectance and Kerr magneto-optical parameters of used structure for different periodicity Λ and thickness of golden films. The height of Fe dots placed in Au matrix has been fixed at 20 nm, the laser incidence beam was p- polarized at the wavelength of 632.8 nm. The results show the sharp reflectance extreme (up to R p = 0.85) as the function of incidence angle. This dependence is importantly modified by Au film thickness. The influence of magneto-optical acti- vity of Fe grating has been studied by Kerr effect in longitudinal configuration. The maximum of rotation achieves is 4 mdeg, the extreme ellip-ticity value is about 3 mdeg. The influence of Au film thickness on Kerr parameters is observed too. The achieved results offer new approaches for MO surface plasmon resonance sensing elements. Index Terms - magneto-optics, sensors, surface plasmon resonance. I. INTRODUCTION Theoretical model of magneto-optical binary grating with cylindrical microdots with the permittivity anisotropy induced by external magnetic field has been presented [1]. As shown in the obtained results, the ratio r/Λ (the dot radius r and period Λ) influences magneto- optical response more expressively than small changes of a single parameter. The non- reciprocity of MO reflection response by surface plasmon excitation in a planar glass/Fe/Au/air system with prism coupling was analysed with the aim to find the optimal thicknesses of metallic layers with regard to the reflectance sensitivity to an external magnetic field [2]. Magneto-optical effect induced in various plasmonic nanostructures has been in recent time studied among other for sand-wiched noble metal/ferromagnetic/noble metal optical system [3-4]. Here, the scattering matrix formalism has been applied to optical response modeling. From “plasmonic” point of view, the properties of periodical array of gold nano-particles submerged into glass have been measured and analyzed via RCWA (rigorous coupled wave analysis) in [5]. The more comp-licated structure with cylindrical dots in Au[Co/Pt] n Au sandwich is discussed in [6] with the help of effective media approximation (EMA). Fig.1. MO-SPR structure. gap Substrate - BK7 Au Au Fe Fe air t 1 t 2 h prism