Complex skin modes in non-Hermitian coupled laser arrays

Area of Science:

• Non-Hermitian physics
• Optics and photonics
• Network science

Background:

• Connectivity is vital for network function, dynamics, and resilience across diverse systems.
• Non-Hermitian physics introduces complex exchange interactions, leading to phenomena like the skin effect and unique bulk-boundary correspondence.
• The Hatano-Nelson model, a theoretical framework for these phenomena, has been challenging to realize in real-space optical platforms due to difficulties in creating asymmetric interactions.

Purpose of the Study:

• To experimentally realize the Hatano-Nelson model in a real-space optical lattice.
• To investigate novel non-Hermitian phenomena in an active optical oscillator network.
• To explore new regimes of laser phase-locking and beam steering.

Main Methods:

• Utilized active optical oscillators with engineered non-Hermiticity and nonlinearity.
• Introduced anisotropic exchange interactions between resonant elements in the lattice.
• Constructed and analyzed a Hatano-Nelson laser array.

Main Results:

• Successfully observed the non-Hermitian skin effect in the laser array.
• Demonstrated novel phase-locking behaviors.
• Achieved near-field beam steering capabilities.
• Validated the experimental realization of the Hatano-Nelson model in real space.

Conclusions:

• This work provides the first experimental demonstration of the Hatano-Nelson model in a real-space optical lattice.
• The findings open new avenues for studying non-Hermitian physics in accessible optical systems.
• The developed platform enables new applications in laser phase-locking and optical beam control.