Journal of Nonlinear Optical Physics & Materials
ENHANCED KERR NONLINEARITY IN A FOUR-LEVEL EIT MEDIUM
Mostafa Sahrai, Seyyed Hossein Asadpour, Rasol Sadighi
Abstract
The linear and nonlinear response of a four-level EIT system driven by three coherent fields is investigated. It is found that at appropriate atomic parameters, the Kerr nonlinearity can clearly be enhanced. It is also demonstrated that the maximal Kerr nonlinearity enters the EIT window, and the corresponding linear and nonlinear absorption suppress. Moreover, we show that nonlinear absorption and Kerr nonlinearity can also be changed via relative phase between driving fields.