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

An integrated photonic platform is proposed for strong interactions between chip-scale atomic beams and high-quality-factor (Q) micro-resonators. We fabricated a thin-film, air-clad SiN microresonator with a loaded Q of 1.55×10^6 around the optical transition of 87Rb at 780 nm [1]. The estimated single-photon Rabi frequency (2g) is 2??×64MHz at 100 nm above the resonator. Our simulation result indicates that slow atomic beams from a 2D+ MOT with a longitudinal speed in the range of 0.2 m/s to 30 m/s will interact strongly with our resonator without crashing. This can allow the detection of single-atom transits and quantum operations during transit time. We also showed that racetrack resonators with a similar Q can be used to detect thermal atomic beams with velocities around 300 m/s. Without the requirement of atom trapping, the ultra-high vacuum would not be needed. Together with the high repetition rate it provides, we believe this platform can set the stage for a new class of scalable single-atom photonic devices on-chip.

 

[1] Dorche, A. E., Wei, B., Raman, C., & Adibi, A. (2020). High-quality-factor microring resonator for strong atom-light interactions using miniature atomic beams. Optics Letters, 45(21), 5958-5961.