Cavity QED with optically transported atoms

Ultracold ⁸⁷Rb0.3em0exatoms are delivered into a high-finesse optical microcavity using a translating optical lattice trap and detected via the cavity field. The atoms are loaded into an optical lattice from a magneto-optic trap and transported 1.50.3em0excm into the cavity. Our cavity satisfies the strong-coupling requirements for a single intracavity atom, thus permitting real-time observation of single atoms transported into the cavity. This transport scheme enables us to vary the number of intracavity atoms from 10.5em0exto0.5em0ex>100 corresponding to a maximum atomic cooperativity parameter of 5400, the highest value ever achieved in an atom-cavity system. When many atoms are loaded into the cavity, optical bistability is directly measured in real-time cavity transmission.