Journal of Physics B Atomic Molecular and Optical Physics
Giant cross-Kerr nonlinearity in a six-level inhomogeneously broadened atomic medium
Le Van Doai
Abstract
Abstract We study the enhancement of cross-Kerr nonlinearity in a six-level inverted-Y-type inhomogeneously broadened atomic medium. The explicit analytical expressions for first- and third-order susceptibilities and cross-Kerr nonlinear coefficient are found in the presence of Doppler broadening. The analytical model is applied to 87 Rb atoms and it is shown that under the electromagnetically induced transparency (EIT) condition, the cross-Kerr nonlinearity is enhanced at multiple frequencies around three EIT windows. The amplitude and sign of the cross-Kerr nonlinear coefficient of the probe field are controlled by changing the parameters of the coupling field. The effect of Doppler broadening leads to a reduction in the transparent efficiency and thus reduces the amplitude of the cross-Kerr nonlinear coefficient. The analytical model can be used to easily fit the experimental observations at different temperatures and support future studies related to the cross-Kerr nonlinear effect.