Robust interface-state laser in non-Hermitian micro-resonator arrays

TL;DR

This paper introduces a novel interface-state laser in non-Hermitian micro-resonator arrays, demonstrating photon gathering and pulsed lasing that is robust against certain defects, driven by nonreciprocal couplings and skin effects.

Contribution

It presents a new scheme for interface-state lasers in topologically trivial non-Hermitian arrays, highlighting defect immunity and photon localization mechanisms.

Findings

Pulsed interface-state laser achieved with photon proliferation at the intermediate resonator.

Photon gathering mainly occurs near the interface due to skin effects.

The laser's robustness is attributed to nonreciprocal couplings, not topology.

Abstract

We propose a scheme to achieve the analogous interface-state laser by dint of the interface between the two intermediate-resonator-coupled non-Hermitian resonator chains. We find that, after introducing the couplings between the two resonator chains and the intermediate resonator at the interface, the photons of the system mainly gather into the three resonators near the intermediate resonator. The phenomenon of the photon gathering towards the certain resonators is expected to construct the photon storage and even the laser generator. We reveal that the phenomenon is induced via the joint effect between the isolated intermediate resonator and two kinds of non-Hermitian skin effects. Specially, we investigate the interface-state laser in topologically trivial non-Hermitian resonator array in detail. We find that the pulsed interface-state laser can be achieved accompanying with the intermittent proliferation of the photons at the intermediate resonator when an arbitrary resonator is excited. Also, we reveal that the pulsed interface-state laser in the topologically trivial non-Hermitian resonator array is immune to the on-site defects in some cases, whose mechanism is mainly induced by the nonreciprocal couplings instead of the protection of topology. Our scheme provides a promising and excellent platform to investigate interface-state laser in the micro-resonator array.