Topological lasing and self-induced transparency in two level systems

TL;DR

This paper demonstrates the potential of topological edge states in two-level systems to enable thresholdless, tunable lasers with topological protection, confirmed through simulations of self-induced transparency and laser emission.

Contribution

It introduces a first-principles simulation of topological lasers using Maxwell-Bloch equations in a two-level topological insulator, showing their ability to emit tunable radiation.

Findings

Self-induced transparency pulses can excite topological edge states.

Simulated topological cavity can emit tunable laser radiation.

First-principles confirmation of topological laser operation.

Abstract

The use of virtually lossless topologically isolated edge states may lead to a novel class of thresholdless lasers operating without inversion. One needs however to understand if topological states may be coupled to external radiation and act as active cavities. We study a two-level topological insulator and show that self-induced transparency pulses can directly excite edge states. We simulate laser emission by a suitable designed topological cavity, and show that it can emit tunable radiation. For a configuration of sites following the off-diagonal Aubry-Andre-Harper model we solve the Maxwell-Bloch equations in the time domain and provide a first principle confirmation of topological lasers. Our results open the road to a new class of light emitters with topological protection for applications ranging from low-cost energetically-effective integrated lasers sources, also including silicon photonics, to strong coupling devices for studying ultrafast quantum processes with engineered vacuum.