Mitigation of dynamical instabilities in laser arrays via non-Hermitian coupling

Abstract

Arrays of coupled semiconductor lasers are systems possessing complex dynamical behavior that are of major interest in photonics and laser science. Dynamical instabilities, arising from supermode competition and slow carrier dynamics, are known to prevent stable phase locking in a wide range of parameter space, requiring special methods to realize stable laser operation. Inspired by recent concepts of parity-time ($\mathcal{P}\mathcal{T}$) and non-Hermitian photonics, in this work we consider non-Hermitian coupling engineering in laser arrays in a ring geometry and show, both analytically and numerically, that non-Hermitian coupling can help to mitigate the onset of dynamical laser instabilities. In particular, we consider in details two kinds of nearest-neighbor non-Hermitian couplings: symmetric but complex mode coupling (type-I non-Hermitian coupling) and asymmetric mode coupling (type-II non-Hermitian coupling). Suppression of dynamical instabilities can be realized in both coupling schemes, resulting in stable phase-locking laser emission with the lasers emitting in phase (for type-I coupling) or with $\pi /2$ phase gradient (for type-II coupling), resulting in a vortex far-field beam. In type-II non-Hermitian coupling, chirality induced by asymmetric mode coupling enables laser phase locking even in presence of moderate disorder in the resonance frequencies of the lasers.

revised version, changed title, added one figure and some references

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Cited by in corpus (19)

• Exceptional Topology of Non-Hermitian Systems
• Nonlinear topological photonics
• Spontaneous coherence in spatially extended photonic systems: Non-Equilibrium Bose-Einstein condensation
• Anomalous single-mode lasing induced by nonlinearity and the non-Hermitian skin effect
• Supersymmetric microring laser arrays
• Non-Hermitian skin effect beyond the tight-binding models
• Theory of the coherence of topological lasers
• Nonlinear mode competition and symmetry-protected power oscillations in topological lasers
• Theory of chiral edge state lasing in a two-dimensional topological system
• Photonic Flatband Laser
• Stochastic non-Hermitian skin effect
• Supercharge optical arrays
• Loschmidt echo and fidelity decay near an exceptional point
• Tunable two-dimensional laser arrays with zero-phase locking
• Non-Hermitian topological phase transitions in superlattices and the optical Dirac equation
• Non-Hermitian laser arrays with tunable phase locking
• Parity anomaly laser
• Topological directed amplification
• Phase transitions in non-Hermitian superlattices