Magnetically Controllable Multimode Interference in Topological Photonic Crystals

TL;DR

This paper demonstrates magnetically controllable multimode interference in topological photonic insulators, enabling reconfigurable photonic devices through manipulation of edge mode interference.

Contribution

It introduces a method to control multimode interference in topological photonics using magnetic fields, advancing reconfigurable photonic device design.

Findings

Achieved controllable power splitting via magnetic field or frequency tuning.

Demonstrated interference control among two unidirectional edge modes.

Supported experimental validation of multimode interference manipulation.

Abstract

Topological photonic insulators show promise for applications in compact integrated photonic circuits due to their ability to transport light robustly through sharp bendings. The number of topological edge states relies on the difference between the bulk Chern numbers across the boundary, as dictated by the bulk edge correspondence. The interference among multiple topological edge modes in topological photonics systems may allow for controllable functionalities that are particularly desirable for constructing reconfigurable photonic devices. In this work, we demonstrate magnetically controllable multimode interference based on gyromagnetic topological photonic insulators that support two unidirectional edge modes with different dispersions. We successfully achieve controllable power splitting in experiments by engineering multimode interference with the magnetic field intensity or the frequency of wave. Our work demonstrates that manipulating the interference among multiple chiral edge modes can facilitate the advancement of highly efficient and adaptable photonic devices.