Storing light near an exceptional point

• Published in: Nature communications Vol. 15; no. 1; pp. 8101 - 7
• Main Authors: Zhu, Yicheng, Hou, Jiankun, Geng, Qi, Xue, Boyi, Chen, Yuping, Chen, Xianfeng, Ge, Li, Wan, Wenjie
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 16.09.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/1130/2800; 639/766/400/1102; Atomic properties; Atomic radius; Critical point; Data processing; Humanities and Social Sciences; Hybrid modes; Information processing; Light; multidisciplinary; Photons; Quantum phenomena; Room temperature; Scattering; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-52064-4

Photons with zero rest mass are impossible to be stopped. However, a pulse of light can be slowed down and even halted through strong light-matter interaction in a dispersive medium in atomic systems. Exceptional point (EP), a non-Hermitian singularity point, can introduce an abrupt transition in dispersion. Here we experimentally observe room-temperature storing light near an exceptional point induced by nonlinear Brillouin scattering in a chip-scale 90-μm-radius optical microcavity, the smallest platform up to date to store light. Through nonlinear coupling, a Parity-Time (PT) symmetry can be constructed in optical-acoustical hybrid modes, where Brillouin scattering-induced absorption (BSIA) can lead to both slow light and fast light of incoming pulses. A subtle transition of slow-to-fast light reveals a critical point for storing a light pulse up to half a millisecond. This compact and room-temperature scheme of storing light paves the way for practical applications in all-optical communications and quantum information processing. Exceptional point introduces the ability to control and tune light propagation. Here the authors demonstrate a 90-μm-radius optical microcavity to store light, induced by nonlinear Brillouin scattering at room temperature.