Superfluorescence and amplified spontaneous emission in an inhomogeneously broadened medium

The emission from a high gain pencil-shaped volume of inhomogeneously broadened (T¹₂) and initially completely inverted two-level atoms is described fully quantum-mechanically taking into account propagation along the pencil axis. The emission is shown to be superfluorescence for T¹₂ ? √τRτD and amplified spontaneous emission for τR ? T¹₂ ? √τRτD, where τR and τD are the collective decay time and the delay time of pure (T¹₂ = ∞) superfluorescence, respectively.