Incident Direction Independent Wave Propagation and Unidirectional Lasing

Area of Science:

• Optics and Photonics
• Quantum Optics
• Materials Science

Background:

• Unidirectional destructive interferences (UDIs) are crucial for controlling light propagation.
• Achieving single-direction lasing and absorption typically requires nonlinearity or complex structures.
• Parity-time (PT) symmetry offers a framework for novel optical phenomena.

Purpose of the Study:

• To propose a new approach for incident direction independent wave propagation.
• To achieve unidirectional lasing and perfect absorption without nonlinearity.
• To explore the combination of UDIs with PT symmetry for advanced optical functionalities.

Main Methods:

• Assembling different unidirectional destructive interferences (UDIs).
• Matching synthetic magnetic fluxes with the incident wave vector.
• Implementing parity-time-symmetric configurations.

Main Results:

• Demonstrated incident direction independent wave propagation.
• Achieved single-direction lasing at spectral singularity without nonlinearity.
• Combined UDIs with PT symmetry to eliminate spectral singularities while maintaining bounded reflections and transmissions.
• Created simultaneous unidirectional lasing and perfect absorption for opposite incident directions.

Conclusions:

• The proposed method offers a robust way to control wave propagation directionally.
• UDIs provide a pathway to nonlinear-free unidirectional lasing and absorption.
• The integration of UDIs and PT symmetry unlocks new functionalities in optical devices.
• Findings have implications for fundamental light control and practical optical applications.