arXiv:1411.1824 · Journal of Optics
Reversible self–Kerr nonlinearity in an N-type atomic system through a switching field
Xu Yang, Kang Ying, Yueping Niu, Shangqing Gong
Abstract
We investigate the self–Kerr nonlinearity of a four-level N-type atomic system in 87 Rb and observe its reversible property with a unidirectional increase in the switching field. For a laser arrangement in which the probe field interacts with the middle two states, the slope and the sign of the self–Kerr nonlinearity around the atomic resonance not only can be changed from negative to positive but also can be changed to negative again with a unidirectional increase in the switching field. Numerical simulations are consistent with the experimental results, and dressed state analysis is presented to explain the experimental results.