A noninversion laser system which is closed lifetime broadened and free of the restriction on atomic decay rates is proposed. For the realization of lasing without inversion, the Rabi frequency of the applied field must exceed a lower threshold. Moreover, the coherence term in dressed states must enhance the gain. These results are obtained beyond the specific approximations.

• Received 26 August 1992

DOI:https://doi.org/10.1103/PhysRevA.47.1579