Optimizing Photon Collection from Ytterbium Atom-Cavity Systems

Neutral atoms in cavities are a promising platform for quantum communication. By placing atoms within a cavity, strong light-matter interactions can be engineered to enhance the emission and collection of photons. Ytterbium atoms are uniquely suited for this system, in part, for offering a telecom-band transition — at 1389 nm — out of a highly coherent nuclear spin qubit state. On-chip cavities, such as photonic crystal cavities, can offer a modular footprint compatible with existing atomic physics experiments. We investigate inverted-taper waveguide designs for the purpose of optimizing light collection into optical fibers. We characterize the coupling efficiency at 1389 nm with differing end-coupler waveguide widths, ranging from 100-701 nm, to identify the optimal geometry for the best photon collection.