2-TIME INTENSITY CORRELATION IN A DRIVEN 3-LEVEL SYSTEM

We examine the various two-time fluorescence intensity correlations em itted by a driven three-level atom in a cascade configuration. For a s trongly driven atom, the two intensity autocorrelation functions, one from the upper transition, the other from the lower transition, exhibi t different behaviors. In addition to the an oscillation similar to th e two-level intensity correlation we find an additional oscillation fo r the upper transition only. This is shown to be due to the spontaneou s decay between the lower transition levels.