Cascaded optical cavities with two-level atoms: Steady state

We have experimentally studied the steady-state characteristics of a cascaded quantum-optical system. The conceptually simple apparatus consists of a pair of high finesse cavities traversed by a beam of optically prepared two-level atoms. The output from the first cavity is coupled through a unidirectional device into the second cavity. The experimental results show quantitative agreement with a model that takes into account the geometric factors of the cavity modes and treats the two-level atoms as being purely radiatively broadened.