Long-lived elementary excitations and light coherence in topological lasers
Citation
Zapletal, P., Galilo, B., & Nunnenkamp, A. Long-lived elementary excitations and light coherence in topological lasers. Optica https://doi.org/10.17863/CAM.55429
Abstract
Combining topologically-protected chiral light transport and laser amplification gives rise to topological lasers, whose operation is immune to fabrication imperfections and defects, uncovering the role of topology in a novel nonlinear non-Hermitian regime. We study a topological laser based on the photonic Haldane model with selective pumping of chiral edge modes described by saturable gain. We investigate elementary excitations around the mean-field steady state and their consequences for the coherence properties. In particular, we show that the hybridization of chiral edge modes gives rise to long-lived elementary excitations, leading to large phase fluctuations in the emitted light field and a decrease of light coherence. In contrast to topologically trivial lasers, the lifetime of elementary excitations is robust against disorder in topological lasers. However, the lifetime strongly depends on the edge-mode dispersion around the lasing frequency. As a result, the lifetime can be reduced by orders of magnitude for lasing of different edge modes, leading to a suppression of phase fluctuations and larger coherence of the emitted light. On the other hand, amplitude fluctuations and the second-order autocorrelation function are moderately increased at the same time.
Sponsorship
European Union’s Horizon 2020 research and innovation programme under grant agreement No 732894 (FET Proactive HOT), Royal Society (University Research Fellowship), Winton Programme for the Physics of Sustainability
Funder references
European Commission Horizon 2020 (H2020) Future and Emerging Technologies (FET) (732894)
Embargo Lift Date
2023-07-23
Identifiers
This record's DOI: https://doi.org/10.17863/CAM.55429
This record's URL: https://www.repository.cam.ac.uk/handle/1810/308337
Rights
All rights reserved