Harnessing coupled nanolasers near exceptional points for directional emission

TL;DR

This paper demonstrates a pump-controlled nanolaser system that exploits exceptional points in non-Hermitian physics to achieve reconfigurable, directional emission, advancing integrated nanophotonics technology.

Contribution

It introduces a novel coupled nanolaser setup with tunable frequency and loss interactions to reach exceptional points and control emission directionality.

Findings

Achieved pump-controlled directional emission in coupled nanolasers.

Enabled reconfiguration from bidirectional to unidirectional emission.

Utilized frequency- and loss-couplings to reach exceptional points.

Abstract

Tailoring the losses of optical systems within the frame of non-Hermitian physics has appeared very fruitful in the last few years. In particular, the description of exceptional points (EPs) with coupled resonators have become widespread. The on-chip realization of these functionalities is highly significant for integrated nanophotonics, but requires fine control techniques of the nanodevice properties. Here, we demonstrate pump-controlled directional emission of two coupled nanolasers that distantly interact via an integrated waveguide. This coupling scheme unusually enables both frequency- and loss-couplings between two cavities, which can be advantageously exploited to reach EPs by either detuning the cavities or controlling the gain of nanolasers. The system can be readily reconfigured from bidirectional to unidirectional emission by adjusting the pump power.