Enabling lasing action in hybrid atomic-nanophotonic integrated structures

The incorporation of neutral atoms in nanophotonic structures offers significant potential to realize novel quantum optical devices. Here, the possibility of creating low-threshold integrated lasers in hybrid systems based on coupling room-temperature atomic gases with both dielectric and metallic nanophotonic systems is investigated. Two different classes of devices resulting from incorporating an optically pumped Rb-ethane mixture in a dielectric ring resonator and a plasmonic lattice are studied. It is shown that the combination of the optical gain provided by the atomic vapor, along with the unique field-confinement properties of nanophotonic structures, enables the generation of coherent radiation, that is, laser light, at moderate power levels. In addition, general design guidelines for these hybrid nanophotonic lasers are provided. These results pave the way toward a novel class of active nanophotonic and metamaterial systems. (copyright 2018 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)