Line shapes of atomic transitions in excited dense gas

We discuss recently published results of experimental studies of dipole-dipole broadened line shapes in excited atomic vapors. The Lorentz local-field shift and self-broadened width were measured in optically excited potassium and rubidium vapors. Strong reduction of the shift and width was observed. This effect allowed resolve electromagnetically induced dressed states inside the self-broadened spectral profile. The experimental results were interpreted using well-known models of the dipole-dipole interactions.