Tailoring transverse magneto-optical Kerr effect enhancement in Mie-resonant nanowire-based metasurfaces

Abstract

Tailoring of the transverse magneto-optical Kerr effect (TMOKE) in hybrid metasurfaces comprising rectangular silicon nanowires coupled with a nickel substrate is demonstrated. The excitation of Mie modes of different orders in nanowires causes TMOKE enhancement. The in-plane magnetic dipole mode leads to the largest TMOKE enhancement compared to other Mie modes. Changing the width of silicon nanowires entails a modification of that mode, thereby ensuring tailoring of the TMOKE within the range of 2.2%–3.8%. This tunability is associated with the modification of the near-field localized at the Si/Ni interface and the far-field response of the excited magnetic dipole mode. Adjusting these two quantities allows one to achieve the highest values of the TMOKE caused by individual Mie modes in silicon nanowires.