Observation of Near-Infrared Dicke Superradiance on Cascading Transitions in Atomic Sodium

Abstract

We report the observation of near-infrared Dicke superradiant pulses. The active medium (atomic Na vapor) is optically pumped in the $5{S}_{\frac{1}{2}}$ state and superradiates on transitions cascading down from this level at 3.41, 2.21, and 9.10 \ensuremath{\mu}m. The superradiant character of the emission is checked by studying variations of pulse heights and delays versus initial population inversion density.