Integrated magneto-plasmonic isolation enhancement based on coupled resonances in subwavelength gold grating

In this paper, we propose and numerically investigate a new non-reciprocal optical device enabling enhanced optical TE mode isolation at telecom wavelength, compatible with applications. The principle is based on magnetoplasmonic interaction between a garnet waveguide and a side-coupled gold grating. Grating nanoslits host Fabry–Perot resonances that couple to Surface Plasmon Polaritons excited at the interface between the metal and the waveguide. Additionally, coarse or fine sensitivity of the Fabry Perot resonances to nanoslits dimensions opens the way to continuously selectable operation frequency of the plasmonic isolator.