Incoherent Resonance Fluorescence from a Rb Atomic Beam Excited by a Short Coherent Optical Pulse

Fluorescence has been detected from Rb atoms following narrow-line excitation by a short coherent optical pulse. The fluorescence oscillates as a function of the pulse area A with maxima for A=π,3π,5π, and minima for A=0,2π,4π,. In addition to demonstrating one of the simplest coherent optical effects, this experiment dramatizes the potential of the technique for determining dipole moments, pulse areas, relaxation times, and lifetimes. The details of the experimental apparatus are described. Results of a computer simulation of the experiment including the actuai excitation pulse shape, absorption frequency width, finite absorption (5-10% of pulse), and loss to a third level are given.