Switchable plasmonic routers controlled by external magnetic fields by using magneto-plasmonic waveguides

TL;DR

This paper proposes a magnetically controlled plasmonic router using magneto-plasmonic waveguides, achieving high-contrast switching and modulation within the optical bandwidth by manipulating mode distribution with external magnetic fields.

Contribution

It introduces a novel waveguide design enabling switchable plasmonic routing controlled by magnetic fields, with high contrast and potential for modulation applications.

Findings

Achieves 99% high contrast switching.

Operates within tens of THz optical bandwidth.

Demonstrates magnetically controlled energy concentration.

Abstract

We analytically and numerically investigate magneto-plasmons in metal films surrounded by a ferromagnetic dielectric. In such waveguide using a metal film with a thickness exceeding the Skin depth, an external magnetic field in the transverse direction can induce a significant spatial asymmetry of mode distribution. Superposition of the odd and the even asymmetric modes over a distance leads to a concentration of the energy on one interface which is switched to the other interface by the magnetic field reversal. The requested magnitude of magnetization is exponentially reduced with the increase of the metal film thickness. Based on this phenomenon, we propose a waveguide-integrated magnetically controlled switchable plasmonic routers with 99-%-high contrast within the optical bandwidth of tens of THz. This configuration can also operate as a magneto-plasmonic modulator.