Topological Lasing from Thouless Pumping in Bilayer Photonic Crystal

TL;DR

This paper demonstrates a reconfigurable topological laser in a bilayer photonic crystal using Thouless pumping, enabling robust, tunable light sources at telecom wavelengths through dynamic phase transitions.

Contribution

It introduces a bilayer photonic crystal platform that combines topological pumping with reconfigurable elements like MEMSs and PCMs for tunable topological lasing.

Findings

Achieved topological lasing at telecom wavelengths.

Demonstrated dynamic tuning via MEMSs and PCMs.

Established a programmable platform for topological light sources.

Abstract

Topological lasing leverages concepts from topological physics to achieve single-mode light amplification within topological bandgaps, offering robustness against fabrication imperfections. Recent advances in microelectromechanical systems (MEMSs) and phase-change materials (PCMs) at the subwavelength scale promise new avenues for dynamically reconfigurable topological lasers, enabling robust and tunable nanoscale light sources. Here, we numerically demonstrate a dynamically reconfigurable lasing action at telecom wavelengths in a bilayer photonic crystal through the mechanisms of Thouless pumping. By designing two competing periodic potentials -- one slowly translating photonic grating atop another stationary one -- we observe a transition between a topological pumping regime and conventional mode oscillation. A carefully engineered heterojunction between these phases supports a robust lasing mode that can be dynamically tuned via MEMSs or reversible PCMs. Our work establishes bilayer photonic crystals as a programmable platform for achieving topological light sources, showcasing a potential pathway for merging topological photonics with reconfigurable photonic devices.