LAUSR

The integration of neutral atoms with nanophotonic structures offer significant potential as a versatile platform to explore fundamental light-matter interactions as well as realizing novel quantum-optical devices. Here, we investigate the possibility of creating low-threshold microscale lasers in hybrid systems based on integrating room-temperature atomic gases with both dielectric and metallic nanophotonic systems. We particularly focus on studying two different devices resulting from incorporating an optically-pumped Rb-ethane mixture in a dielectric ring resonator and a plasmonic lattice. We show in both cases the combination of the optical gain provided by the atomic vapor, along with the unique field-confinement properties of nanophotonic structures, enables generating of coherent radiation, i.e. laser light, at low power levels. In addition, we provide general design guidelines for these hybrid nano-lasers and an efficient density matrixbased formalism for studying these systems. Our results demonstrate a unique route towards small foot-print, highly efficient, and fast lasers, which paves the way towards the development of a whole new class of active nanophotonic and metamaterial systems. 1 ar X iv :1 70 9. 08 71 5v 1 [ ph ys ic s. op tic s] 2 5 Se p 20 17