Enhanced magneto-optical effect in three layer based magnetoplasmonic structures

In this article we introduce a magnetoplasmonics (MP) planar nanostructure with enhanced transverse magneto-optical (MO) activity. For this goal MO characteristics of magneto-structures containing both metal layer and linear array of (metal) nanorods are analyzed. We explore three types of structures with nanorods and compare their features based on transvers magneto-optical Kerr effect (TMOKE) with the corresponding one for conventional three layers MO structure. Comparison between the values of TMOKE signals in two structures (proposed and conventional) shows more than one order of magnitude improvement. Accordingly, the refractive index sensitivity of the offered structures, specially with one and three types of Au nanorod arrays, appearance more than 2 order of magnitude larger than the conventional Au/Co/Au three layer MO structures. This notable response enhancement becomes serious affair in MP biosensing applications. We believe that our idea in these proposed nanostructures can be used in any other three layer based MO structures in the literature. On this basis, we apply this scenario to other types of such MO structures which leads to improvement in their MO activities and whereupon in their refractive index sensitivities.