AI Insight
Researchers have experimentally demonstrated a "topological antilaser," which is the time-reversed counterpart of a topological laser that achieves perfect light absorption protected by topological properties. Using a nonreciprocal microwave network, they showed that this device maintains near-complete absorption even under strong disorder and structural imperfections, unlike conventional coherent perfect absorbers which are fragile to such perturbations. The robustness stems from chiral edge modes in the photonic lattice that are immune to disorder and maintain stable spatial profiles regardless of where dissipation or input ports are placed.
Why it matters
This work establishes a fundamental symmetry between topological lasing and absorption, potentially enabling robust energy harvesting and detection technologies that function reliably in real-world conditions with inherent imperfections. The topological protection could lead to practical applications in wave control systems, optical computing, and sensing devices that require consistent performance despite environmental variations or manufacturing defects.
arXiv:2601.17719v2 Announce Type: replace
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.
Source: Topological antilaser