High-quality-factor microring resonator for strong atom-light interactions using miniature atomic beams

An integrated photonic platform is proposed for strong interactions between atomic beams and annealing-free high-quality-factor (Q) microresonators. We fabricated a thin-film, air-clad SiN microresonator with a loaded Q of 1.55×10⁶ around the optical transition of ⁸⁷Rb at 780 nm. This Q is achieved without annealing the devices at high temperatures, enabling future fully integrated platforms containing optoelectronic circuitry. The estimated single-photon Rabi frequency (2g) is 2π×64MHz 100 nm above the resonator. Our simulation result indicates that miniature atomic beams with a longitudinal speed of 0.2 m/s to 30 m/s will interact strongly with our resonator, allowing for the detection of single-atom transits and realization of scalable single-atom photonic devices. Interactions between racetrack resonators and thermal atomic beams are also simulated.