Tailoring Transverse Magneto-Optical Kerr Effect Enhancement in Mie-resonant Nanowire-based Metasurfaces

TL;DR

This paper demonstrates how to enhance and tailor the transverse magneto-optical Kerr effect in silicon nanowire metasurfaces by exploiting Mie resonances and adjusting nanowire dimensions, achieving tunable TMOKE responses.

Contribution

It introduces a method to enhance and tune TMOKE in hybrid silicon nanowire metasurfaces through Mie mode excitation and nanowire width modification, providing control over the effect.

Findings

Maximum TMOKE enhancement of 3.8% achieved with magnetic dipole mode.

TMOKE can be tuned between 2.2% and 3.8% by adjusting nanowire width.

In-plane magnetic dipole mode is responsible for the largest TMOKE enhancement.

Abstract

Enhancement and tailoring of the transverse magneto-optical Kerr effect (TMOKE) in hybrid metasurfaces comprising rectangular silicon nanowires coupled with a nickel substrate are demonstrated. The excitation of Mie modes of different orders in nanowires causes the enhancement. The in-plane magnetic dipole mode leads to the largest TMOKE enhancement compared to other Mie modes. Changing the width of silicon nanowires leads to a modification of that mode, thereby ensuring the 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.