Abstract 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.
Abstract 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.
Over the past decades, alkali atoms have been the subject of intensive and diverse research, ranging from fundamental studies on ultra-cold atoms and Bose-Einstein condensates to technological applications. Since they possess only a single valance s-electron, the alkali atoms manifest a simple low-lying electronic structure compared to other atoms. Moreover, unlike conventional solid state systems their dispersion-free features make them an ideal candidate for sensing applications and referencing tasks. These two features have introduced alkali atoms as promising quantum emitters for the new paradigm of hybrid quantum optics and quantum electrodynamics. This new concept benefits from the existing integrated photonics technology for squeezing and confining the light in sub-wavelength scales to substantially enhance the light-atom interaction. The hybrid chip is envisioned to have light sources, waveguides, devices, and detectors to realize a complex quantum network down to a single photon level. In this talk I will discuss about our recent theoretical and experimental works on atomic vapor spectroscopy in the vicinity of the plasmonic and nanophotonic devices. I start from a density matrix-based formalism describing the evolution of Rb vapor atomic levels, excited with an incoherent pump and coupled to a plasmonic lattice. When designed properly, the lattice plasmon mode efficiently captures the spontaneously emitted photons from the excited Rb atoms and a coherent coupling between the lattice mode and the atomic levels would occur. I will elaborate on the effect of pumping rate and decoherence on the steady state of the hybrid system and the feasibility of achieving a lasing state. In the second part of the talk I will present the results of our experiments on Rb vapor coupled to such a plasmonic lattice. Starting from the pumping mechanism, I describe the collisional scheme we employed to transfer the excited Rb atoms from (_^5)P_(3/2) to(_^5)P_(1/2) , hence achieving a population inversion between P and S levels and an optical gain at 795 nm, eventually. I present the experimental results of this atomic vapor interaction with a plasmonic lattice resonating at 795 nm. The spectroscopy of Rb cloud modified with tightly squeezed and enhanced field of the lattice plasmons shows the clear signature of Fano resonances in the passive gas, followed by amplified spontaneous emission in the active gas and the lasing at higher pumping powers. The results of this study would pave the way toward hybrid atom-quantum photonic chips.
Light-matter interaction is the foundation for numerous important quantum optical phenomena, which may be harnessed to build practical devices with higher efficiency and unprecedented functionality. Nanoscale engineering is seen as a fruitful avenue to significantly strengthen light-matter interaction and also make quantum optical systems ultra-compact, scalable, and energy efficient. This research focuses on color centers in diamond that share quantum properties with single atoms. These systems promise a path for the realization of practical quantum devices such as nanoscale sensors, single-photon sources, and quantum memories. In particular, we explored an intriguing methodology of utilizing nanophotonic structures, such as hyperbolic metamaterials, nanoantennae, and plasmonic waveguides, to improve the color centers performance. We observed enhancement in the color center’s spontaneous emission rate, emission directionality, and cooperativity over a broad optical frequency range. Additionally, we studied the effect of plasmonic environments on the spin-readout sensitivity of color centers. The use of CMOS-compatible epitaxially grown plasmonic materials in the design of these nanophotonic structures promises a new level of performance for a variety of integrated room-temperature quantum devices based on diamond color centers.
Abstract Quantum nanophotonics places nanoscale structuring in direct dialogue with photonic quantum information—compressing functionality to the few-nanometre, few-femtosecond frontier while retaining energy efficiency, speed and room-temperature operation. We highlight nanoplasmonic cavity-QED architectures in which extreme mode confinement delivers strong coupling under ambient conditions, enabling ultrafast single-photon emission and near-field multipartite entanglement using industry-grade near-field transducers that nanofocus guided light at practical efficiencies. We set these advances against the arc from early plasmonic cQED proposals and single-emitter Purcell studies to modern time-domain measurements that resolve sub-picosecond polariton/Rabi dynamics—establishing a clear route from concept to device. In parallel, we point to low-loss, high-index Mie resonators whose spectrally sharp electric and magnetic modes afford narrow-band coherent control, filtering and radiation-pattern engineering, and which naturally co-integrate in hybrid metal–dielectric stacks that combine ultrastrong local coupling with low-loss routing and storage. Finally, we discuss quantum nanoplasmonic coherent perfect absorption (qnCPA)—a waveguide-fed, non-perturbing protocol that selectively prepares and protects plasmon–emitter dressed states via dissipation-assisted, unidirectional feeding. Together with macroscopic QED and quantum quasinormal-mode quantization, which regularize open, lossy resonators and clarify when loss can be a resource, these developments chart robust, chip-scale routes to room-temperature quantum technologies.
Abstract A key obstacle for all quantum information science and engineering platforms is their lack of scalability. The discovery of emergent quantum phenomena and their applications in active photonic quantum technologies have been dominated by work with single atoms, self‐assembled quantum dots, or single solid‐state defects. Unfortunately, scaling these systems to many quantum nodes remains a significant challenge. Solution‐processed quantum materials are uniquely positioned to address this challenge, but the quantum properties of these materials have remained generally inferior to those of solid‐state emitters or atoms. Additionally, systematic integration of solution‐processed materials with dielectric nanophotonic structures has been rare compared to other solid‐state systems. Recent progress in synthesis processes and nanophotonic engineering, however, has demonstrated promising results, including long coherence times of emitted single photons and deterministic integration of emitters with dielectric nano‐cavities. In this review article, these recent experiments using solution‐processed quantum materials and dielectric nanophotonic structures are discussed. The progress in non‐classical light state generation, exciton‐polaritonics for quantum simulation, and spin‐physics in these materials is discussed and an outlook for this emerging research field is provided.
Strongly interacting atom–cavity systems within a network with many nodes constitute a possible realization for a quantum internet which allows for quantum communication and computation on the same platform. To implement such large-scale quantum networks, nanophotonic resonators are promising candidates because they can be scalably fabricated and interconnected with waveguides and optical fibers. By integrating arrays of ring resonators into a vapor cell we show that thermal rubidium atoms above room temperature can be coupled to photonic cavities as building blocks for chip-scale hybrid circuits. Although strong coupling is not yet achieved in this first realization, our approach provides a key step towards miniaturization and scalability of atom–cavity systems.
Strongly interacting atom–cavity systems within a network with many nodes constitute a possible realization for a quantum internet which allows for quantum communication and computation on the same platform. To implement such large-scale quantum networks, nanophotonic resonators are promising candidates because they can be scalably fabricated and interconnected with waveguides and optical fibers. By integrating arrays of ring resonators into a vapor cell we show that thermal rubidium atoms above room temperature can be coupled to photonic cavities as building blocks for chip-scale hybrid circuits. Although strong coupling is not yet achieved in this first realization, our approach provides a key step towards miniaturization and scalability of atom–cavity systems.