Long-lived elementary excitations and light coherence in topological lasers

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.

arXiv comment13 pages, 5 figures; Sections 1 and 6 revised in v2; Appendices A, D and G added in v2

References in corpus (19)

• Topological Photonics
• Experimental realisation of the topological Haldane model
• Imaging topological edge states in silicon photonics
• Robust optical delay lines via topological protection
• Lasing in topological edge states of a 1D lattice
• Nonlinear topological photonics
• Exciton-polariton topological insulator
• Complex Edge-State Phase Transitions in 1D Topological Laser Arrays
• Topological Hybrid Silicon Microlasers
• Photonic Topological Insulator in Synthetic Dimensions
• Synthetic dimensions in integrated photonics: From optical isolation to 4D quantum Hall physics
• Experimental realization of a Weyl exceptional ring
• A single photonic cavity with two independent physical synthetic dimensions
• Topological states of non-Hermitian systems
• Photonic gauge potential in a system with a synthetic frequency dimension
• Level attraction in a microwave optomechanical circuit
• Unstable Avoided Crossing in Coupled Spinor Condensates
• Theory of chiral edge state lasing in a two-dimensional topological system
• Ab-initio multimode linewidth theory for arbitrary inhomogeneous laser cavities

Cited by in corpus (9)

• Theory of the coherence of topological lasers
• An operator-based approach to topological photonics
• Single-mode lasing based on PT-breaking of two-dimensional photonic higher-order topological insulator
• Tunable two-dimensional laser arrays with zero-phase locking
• Unravelling the edge spectra of non-Hermitian Chern insulators
• Kibble-Zurek mechanism in polariton graphene
• Linearized theory of the fluctuation dynamics in 2D topological lasers
• Bogoliubov theory of the laser linewidth and application to polariton condensates
• Fate of Bosonic Topological Edge Modes in the Presence of Many-Body Interactions