Investigation of electromagnetically induced transparency in the strong probe regimen

Summary form only given. Though experiments in which a strong probe field was applied to an EIT system have been performed using pulsed lasers, previous investigations of the steady-state response of an EIT system to cw lasers have focused on the limit in which the probe field is weak. We investigate the behavior of an inhomogeneously broadened ladder system interacting with probe and control fields that are both strong. The experimental system we study is a gas of /sup 85/Rb atoms, where the lower level is the 5S/sub 1/2/ state, the intermediate level is the 5P/sub 3/2/ state, and the upper level is the 5D/sub 5/2/ state. To facilitate two-photon Doppler cancellation, the control and probe laser beams are counterpropagating. We theoretically model the response of this system by numerically solving the appropriate system of density-matrix equations without any approximations with respect to the strength of the control or probe field, and then numerically performing a Doppler average over the atomic velocity distribution.