Non-Hermitian gauged laser arrays with localized excitations: Anomalous threshold and generalized principle of selective pumping

Abstract

We investigate non-Hermitian skin modes in laser arrays with spatially localized excitation. Intriguingly, we observe an unusual threshold behavior when selectively pumping either the head or the tail of these modes: both cases exhibit the same lasing threshold and hence defy the conventional principle of selective pumping, which aims to maximize the overlap between the pump profile and the target lasing mode. To shed light on this enigma, we reveal a previously overlooked phenomenon, i.e., energy exchange at non-Hermitian coupling junctions with the photonic environment, which does not occur with uniform gain or loss. Utilizing a transfer matrix approach, we elucidate the mechanism of this anomalous threshold behavior, which is determined by the specific physical realization of the non-Hermitian gauge field (i.e., using gain, loss, or their mixture). Finally, we derive a generalized principle of selective pumping in non-Hermitian arrays, which shows that the decisive spatial overlap is given by the tripartite product of the pump, the lasing mode, and its biorthogonal partner. Our study provides a glimpse into how the two forms of non-Hermiticity, i.e., asymmetric couplings and a complex onsite potential, interact synergetically in laser arrays, which may stimulate further explorations of their collective effects in photonics and related fields.

12 pages, 10 figures

References in corpus (13)

• Efficient Light Funneling based on the non-Hermitian Skin Effect
• Selective enhancement of topologically induced interface states in a dielectric resonator chain
• Supporting Online Material for "Strong Interactions in Multimode Random Lasers"
• Strong Interactions in Multimode Random Lasers
• Acoustic non-Hermitian skin effect from twisted winding topology
• Non-Hermitian Morphing of Topological Modes
• Chaos-assisted directional light emission from microcavity lasers
• Symmetry-protected zero-mode laser with a tunable spatial profile
• Ab initio self-consistent laser theory and random lasers
• Controllable Asymmetric Phase-Locked States of the Fundamental Active Photonic Dimer
• Imaginary gauge transformation in momentum space and Dirac exceptional point
• Optical fluxes in coupled $\mathcal{P}\mathcal{T}$-symmetric photonic structures
• Condensation of Thresholds in Multimode Microlasers

Cited by in corpus (5)

• Robust zero modes in non-Hermitian systems without global symmetries
• Non-Hermitian systems with a real spectrum and selective skin effect
• Exceptional points in SSH-like models with hopping amplitude gradient
• Observing complementary Lucas sequences using non-Hermitian zero modes
• Floquet multiple exceptional points with higher-order skin effect