Incident Direction Independent Wave Propagation and Unidirectional Lasing

TL;DR

This paper introduces a method for incident direction independent wave propagation using unidirectional destructive interferences, enabling unidirectional lasing and perfect absorption without nonlinearity, with potential applications in light control.

Contribution

It presents a novel approach to achieve incident direction independent wave propagation and unidirectional lasing through synthetic magnetic fluxes and interference assembly, without nonlinear elements.

Findings

Achieves incident direction independent wave propagation.

Demonstrates unidirectional lasing at spectral singularity.

Realizes unidirectional perfect absorption and combined functionalities.

Abstract

We propose an incident direction independent wave propagation generated by properly assembling different unidirectional destructive interferences (UDIs), which is a consequence of the appropriate match between synthetic magnetic fluxes and the incident wave vector. Single-direction lasing at spectral singularity is feasible without introducing nonlinearity. UDI allows unidirectional lasing and unidirectional perfect absorption; when they are combined in a parity-time symmetric manner, the spectral singularities vanish with bounded reflections and transmissions. Furthermore, the simultaneous unidirectional lasing and perfect absorption for incidences from opposite directions is created. Our findings provide insights into light control and may shed light on the explorations of desirable functionality in fundamental research and practical applications.