The possibility of transparency against two photon absorption is predicted. Detailed absorption profiles under different conditions of the control laser are given. A novel explanation of the absorption minimum is given in terms of the two photon Fermi golden rule and the dressed states. Possibility of considerable enhancement of two photon absorption even in the presence of Doppler broadening is demonstrated.

• Received 29 February 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.1039