Enhancement of the nonlinearity via interacting dark resonances
Xiang-an Yan, Liqiang Wang
A scheme for large enhancement of the third-order nonlinearity in a four-level system with double dark resonances is proposed. We obtain an analytical expression for the linear susceptibility and nonlinear susceptibility of a weak probe field and show that the properties of double electromagnetically induced transparency and the Kerr nonlinearity can be modified significantly by changing the ratio of the two coupling fields. A physical understanding of our numerical results using the dressed-state approach is presented. The obtained large nonlinearity with vanishing absorption can be used to generate optical solitons, polarization phase gates and optical Kerr shutters.
Cross Strait Radio Science and Wireless Technology Conference (CSRSWTC)•Jul 1, 2011•0 citations