Topological Anderson Random Laser

TL;DR

This paper introduces a topological Anderson random laser (TARL) that uses disorder to induce a topological phase, enabling robust, single-mode lasing with high coherence and efficiency.

Contribution

It demonstrates that disorder can induce a topological phase in photonic lattices, leading to a new class of robust, high-coherence random lasers with topologically protected edge states.

Findings

Disorder drives the system into a topological Anderson insulator regime.

TARL exhibits rapid mode selection and ultranarrow emission spectrum.

It shows enhanced robustness and coherence compared to conventional random lasers.

Abstract

Topological lasers and random lasers embody two contrasting strategies for disorder management in photonics: the former suppresses disorder via protected edge transport, while the latter exploits multiple scattering for feedback. Here, we theoretically demonstrate that these seemingly incompatible paradigms can be unified through a topological Anderson random laser (TARL), where disorder itself induces a topological phase that enables robust lasing. Starting from a trivial photonic lattice, we show that engineered disorder drives the system into a topological Anderson insulator regime, generating emergent chiral edge states that serve as boundary-selective lasing channels. Remarkably, the TARL exhibits rapid mode selection toward a single edge state, producing an ultranarrow emission spectrum and enhanced slope efficiency optimized near disorder strength with maximal topological mobility gap. Furthermore, they exhibit single-mode-like coherence properties, deviating from Kardar-Parisi-Zhang behavior in conventional chiral topological lasers, while remaining significantly more robust against local perturbations than conventional random lasers. Our findings establish a disorder-enabled flexible route to topologically protected single-mode lasing and introduce a fundamentally new design principle for robust, high-coherence photonic light sources.