We propose an optical scheme to control the degree of excitation of spatially localized regions inside an absorbing three-level medium using two suitably delayed laser pulses. Only selected localized regions inside the medium are changed by the pulses, the remaining medium remains unchanged in its ground state. We present an approximate but analytical theory of the coupled Liouville and Maxwell equations and propose an experimental verification of this control excitation scheme for potassium vapor.

• Received 5 December 1997

DOI:https://doi.org/10.1103/PhysRevA.57.4860