Topological Microlaser with a Non-Hermitian Topological Bulk

Area of Science:

• Topological states of matter
• Non-Hermitian physics
• Photonics

Background:

• Bulk-edge correspondence is a key feature of topological matter, linking bulk topology to protected edge states.
• While well-established in Hermitian systems, the behavior of bulk-edge correspondence in non-Hermitian systems remains an active research area.
• Non-Hermiticity offers unique properties and device potential, but defining bulk topology in topological lasers is challenging.

Purpose of the Study:

• To propose and experimentally investigate topological edge-mode lasing with a well-defined non-Hermitian bulk topology.
• To establish a clear bulk-edge correspondence in a non-Hermitian system.
• To explore potential applications in non-Hermitian topological devices.

Main Methods:

• Utilized a one-dimensional array of coupled ring resonators.
• Modeled the system Hamiltonian with an additional synthetic dimension.
• Established an equivalence between the 1D structure and a 2D non-Hermitian Chern insulator.

Main Results:

• Successfully demonstrated topological edge-mode lasing.
• Achieved a well-defined non-Hermitian bulk topology.
• Established a clear bulk-edge correspondence in the proposed system.

Conclusions:

• The proposed system provides a platform for studying non-Hermitian topological effects.
• This work may pave the way for novel non-Hermitian topological device applications.
• The established bulk-edge correspondence in non-Hermitian systems is crucial for future topological device design.