Controllable self-Kerr nonlinearity in a doubly dressed five-level atomic conformation

We theoretically investigate the linear and nonlinear optical properties of a five-level atomic system interacting with multiple electromagnetic fields. The relevant optical Bloch equations are numerically solved via iterative formalism to procure first- and third-order susceptibilities. Our numerical computations reveal that the switching field’s strength can be used as a knob to get either single or multiple transparency windows. It is also identified that colossal Kerr nonlinearity exists within the optical EIT dips. Furthermore, we found that the position, sign and magnitude of self-Kerr index can be manipulated by merely adjusting the Rabi frequency of switching field. We also resort to double dressed state mechanism in order to justify our numerical results. Our findings are of particular interest in multi-channel communication, quantum computation and designing of optical devices.