Non-Hermitian zero mode laser in a nanophotonic trimer

TL;DR

This paper reports the experimental observation of a non-Hermitian zero mode laser in a nanophotonic trimer, demonstrating controllable lasing in a symmetry-protected zero mode with potential applications in optical computing.

Contribution

The study presents the first direct observation of a lasing zero mode in a non-Hermitian nanocavity array, with dynamic control of lasing efficiency via selective pumping.

Findings

Lasing zero mode observed in a non-Hermitian nanocavity trimer.

Efficient excitation achieved with nearly equal pump power in edge cavities.

Lasing efficiency can be dynamically controlled by pumping the center cavity.

Abstract

Symmetry-protected zero modes in arrays of coupled optical elements have attracted considerable attention because they are expected to be robust against coupling disorders. In the Hermitian limit, zero modes are dark ones, i.e. the intensity in one sublattice vanishes; yet, in a non-Hermitian counterpart, zero modes can be bright and feature {\pi}/2 phase difference between sublattices. In this work, we report on the direct observation of a lasing zero mode in a non-Hermitian three coupled nanocavity array. We show efficient excitation for nearly equal pump power in the two extreme cavities. Furthermore, its efficiency can be dynamically controlled by pumping the center cavity. The realization of zero mode lasing in large arrays of coupled nanolasers has potential applications in laser-mode engineering and it opens up promising avenues in optical computing.