Semiclassical calculation of the power saturation of the Kerr effect in Rb vapor

Abstract

The Kerr effect in atomic vapor may be regarded as the power saturation of the susceptibility. Hence the saturable Kerr effect is intimately tied to the standard Kerr effect. Here, we calculate the saturable Kerr effect without free parameters using a two-level system and find good agreement with experimental results. Our approach permits a direct comparison of theory to experiment without an extrapolation to low power as required by previous approaches. An experimentally observed asymmetry between red and blue detuning led us to consider a model with one ground state and three excited states. Such an asymmetry cannot be described by a two-state model. The model predicts about 25% of the observed asymmetry.