A narrow Rabi frequency window for competition between coherent population trapping and Raman absorption

We demonstrate the competition mechanism between the coherent population trapping and two-photon Raman absorption in a ladder-type system of cesium cell. When the Rabi frequency of the probe becomes comparable with the effective decay rate, an electromagnetically induced absorption (EIA) dip emerges at the center of the power broadened EIT peak. While the Rabi frequency of the probe exceeds the effective decay rate, a decoherence created by the strong probe field takes place and two-photon Raman absorption dominates the interaction process.