Chiral States in Coupled-Lasers Lattice by On-Site Complex Potential

Area of Science:

• * Physics
• * Optics
• * Condensed Matter Physics

Background:

• * Chirality control is crucial for topological states, wavefront engineering, and unidirectional communication.
• * Controlling chirality in large oscillator networks is complex, often needing asymmetric coupling or artificial gauge fields.
• * Existing methods for chirality control in bulk states of oscillator networks are complicated.

Purpose of the Study:

• * To present a novel approach for precise control over the chirality of bulk states in large, symmetrically coupled laser networks.
• * To demonstrate a method requiring only local on-site control of loss and frequency.
• * To achieve a nearly pure chiral lasing supermode by tuning a complex potential to an exceptional point.

Main Methods:

• * Introduction of a weak non-Hermitian complex potential to a triangular array of hundreds of symmetrically coupled lasers.
• * Local on-site control of loss and frequency within the laser network.
• * Tuning the complex potential to an exceptional point to influence lasing supermodes.

Main Results:

• * In the unperturbed network, lasing supermodes with opposite chirality (staggered vortex and staggered antivortex) were equally probable.
• * Tuning to an exceptional point resulted in a nearly pure chiral lasing supermode.
• * The inherent nonlinearity of lasers effectively stabilized the chiral state at the exceptional point, ensuring resilience against noise and imperfections.

Conclusions:

• * A new, precise method for controlling chirality in large oscillator networks has been developed.
• * The approach utilizes a non-Hermitian complex potential and local control of loss and frequency.
• * The resulting chiral lasing states are highly resilient, paving the way for advanced optical devices and communication systems.