Single-Mode Surface-Emitting Polariton Lasing with Switchable Polarization in a CsPbBr₃ Microwire Folded Fabry–Pérot Cavity

Miniaturized lasers capable of single-mode emission and switchable output are essential for on-chip optical communication, super-resolution imaging, and quantum information technology. However, current fabrication methods involve costly microfabrication and complex manipulation with external tools, hindering chip-based laser array integration. Herein, we introduce an innovative approach by demonstrating folded Fabry–Pérot microcavity (V-cavity and U-cavity) exciton polaritons in CsPbBr3 microwires with an isosceles right triangle cross-section. The study successfully realizes surface-emitting, low-threshold polariton lasers and achieves single-mode lasers with switchable polarized modes by varying the pump fluence. The straightforward and low-cost polariton laser holds promise for integrated laser arrays on chips, enabling applications such as on-chip laser sources, optical communication, and sensing applications.