All-optical Controllable Double State Switch Based on DIT by Using QD

In this article, we have simulated an all-optical double state controllable switch based on dipole induced transparency using photonic crystal (PC) cavity doped by a 4-level QD [1]. This switch operation is based on the dipole induced transparency phenomenon, where the optical signal has been coupled through the input fiber to the photonic crystal cavity and the optical control fields has been applied normally to the PC surface. We have realized this switch by solving Schrodinger and Poisson equations for inserted 4-level QD in photonic crystal rods, self consistently. Also, by using the proposed structure and applying the control field in the Purcell condition, the absorbing photonic crystal cavity has been converted to transparent one and switching operation has been obtained. In this paper, we have discussed frequency and dynamic operation of the switch and shown that a high quality all-optical switching operation can be obtained.