Optics Letters
Light–atom interaction in an Er:YSO whispering gallery mode resonator
Trevor Kling, Mahdi Hosseini
Abstract
Rare-earth crystals are promising platforms for quantum information, with potentially long coherence times and telecom-compatible optical transitions. In this work, we investigate the optical properties of erbium atoms doped into a whispering gallery mode resonator produced by polishing a yttrium orthosilicate crystal. The multimode resonator demonstrates a bare quality factor of 2.56×10 5 . We demonstrate mode interaction between atoms and the resonator, where an effective quality factor of 8.7×10 7 is induced by spectral hole burning. The Fano interference between the atomic (spectral holes) and optical modes, and the small free-spectral range achieved here, can enable the study of tuning-free linear and nonlinear collective interactions.