LIGHT-SHIFT OPTICAL COHERENT AVERAGING IN RUBIDIUM VAPORS

The sublevel time-domain magnetic-resonance signal is calculated for Rb-85 atoms subjected to static or coherently modulated light-shift fields. We predict and experimentally confirm that the observed light shift may be scaled down by coherent light-shift modulation. We submit that the inhomogeneous light-shift broadening may be removed by this purely optical form of coherent averaging, which is referred to as the "light-shift concertina." Our expressions also indicate that the velocity-changing collisions of atoms in a static light-shift field can cause narrowing of the magnetic-resonance line shape in a manner analogous to the effect of electronic exchange or molecular motion.