Interpretation of transient V scheme amplification without inversion

Amplification without inversion (AWI) in a resonant V-type system is studied using a dressed basis which reduces the coherent interaction of both involved optical transitions to that of a single two-level system. The transient AWI recently reported through a numerical analysis of the density matrix equations of the V-system in the bare atom basis (Zhu Y 1996 Phys. Rev . A 53 2742) is damped Rabi nutation with transient population inversion in this dressed basis. Although the transient AWI in the bare state basis occurs both with and without an incoherent pump field, the integrated probe gain is positive only in the first case.