Topological antilaser

TL;DR

This paper demonstrates a topological antilaser that uses chiral edge modes in a photonic lattice to achieve robust, near-perfect light absorption protected by topology, even under strong disorder and perturbations.

Contribution

It introduces the concept of a topological antilaser, experimentally demonstrating topologically protected perfect absorption using nonreciprocal microwave networks.

Findings

Achieves near-unity absorption under strong disorder

Remains functional regardless of dissipation and input port placement

Maintains stable edge mode propagation despite lattice perturbations

Abstract

Coherent perfect absorption (CPA)-the time-reversed operation of lasing at threshold-relies on finely tuned interference and is intrinsically fragile to disorder and structural imperfections. Whether absorption can be endowed with topological protection, by analogy to topological lasing, has remained an open question. Here, we experimentally demonstrate a topological antilaser: the time-reversed counterpart of a topological laser, in which chiral edge modes of a photonic lattice enable perfect light absorption protected by topology. Using a nonreciprocal microwave network with low intrinsic loss, we show that the topological antilaser preserves near-unity absorption under strong disorder, and, unlike conventional antilasers, remains functional for arbitrary placements of dissipation and input ports, even when the lattice is strongly perturbed. This robustness arises from the disorder-immune propagation and stable spatial profile of the topological edge modes. Our results establish topologically protected absorption as the missing counterpart of topological lasing, opening new directions for studying robust energy dissipation, wave control, and coherent-absorption-based detection technologies.