# Lasing in topological edge states of a 1D lattice

## TL;DR

This paper demonstrates lasing in topological edge states of a 1D polariton lattice, showing robustness to local deformations and opening pathways for chiral lasers and nonlinear topological photonics.

## Contribution

It presents the first experimental realization of lasing in topological edge states within a 1D polariton lattice implementing the SSH model.

## Key findings

- Lasing occurs specifically in topological edge states.
- Lasing persists despite local lattice deformations.
- Potential for developing chiral lasers and exploring nonlinear effects.

## Abstract

Topology describes properties that remain unaffected by smooth distortions. Its main hallmark is the emergence of edge states localized at the boundary between regions characterized by distinct topological invariants. This feature offers new opportunities for robust trapping of light in nano- and micro-meter scale systems subject to fabrication imperfections and to environmentally induced deformations. Here we show lasing in such topological edge states of a one-dimensional lattice of polariton micropillars that implements an orbital version of the Su-Schrieffer-Heeger Hamiltonian. We further demonstrate that lasing in these states persists under local deformations of the lattice. These results open the way to the implementation of chiral lasers in systems with broken time-reversal symmetry and, when combined with polariton interactions, to the study of nonlinear topological photonics.