Coherent Ringing in Superfluorescence

Superfluorescence emitted from small regions of the output face of an initially inverted medium is found to exhibit ringing; this confirms that coherent ringing is an intrinsic property of superfluorescence. The system studied is a pure two-level Rb transition at λ=2.73 {μ}m, prepared in a cell by means of cw single-mode radiation. The Fresnel number of the sample is 1.7.