All optical switching in a three-level V-type atomic medium based on electromagnetically induced transparency

We use electromagnetically induced transparency (EIT) to generate optical switching of the probe laser field according to the pulse modulation of the coupling laser field in a three-level V-type atomic system. When the absence of the coupling laser field, the probe laser field is completely absorbed by the atomic medium at the resonant frequency. However, the probe laser field becomes transparent when the coupling laser field is present. Thus, by turning the coupling laser field ON or OFF, the output signal of the probe laser field is also switched from ON to OFF, and vice versa. To describe this optical switching phenomenon, we derive a set of Maxwell–Bloch equations for the three-level V-type atomic system with laser fields and use a combination of the four-order Runge–Kutta and finite difference numerical methods to simulate the propagation of the probe and coupling laser pulses in the atomic medium. Under the EIT condition, we obtain the optical switching of the probe pulse that modulated according to the coupling pulse. The influence of the switching period as well as the intensity and frequency of the coupling laser field on the optical switching of the probe laser field are also studied.