Kerr nonlinear all-optical switches based on asymmetric plasmonic T-shaped single slit

All-optical switches are considered as a key element in the optical communication systems networks. In this article, the performance of a compact switch, based on asymmetric plasmonic T-shaped single slit structure, coated with Kerr nonlinear dielectric, is analyzed and simulated by the finite-difference time-domain (FDTD) numerical method. In the structure of this plasmonic switch, by utilizing a Fabry-Perot resonance effect, the light-matter interaction length is increased and the sensitivity of the switch to the environment refractive index variations is strengthened. Furthermore, the excitation and modulation processes of the surface plasmon polaritons (SPPs) occur in a single structure which results in a remarkable reduction of the total size of the device. The switching is caused by the Kerr nonlinear self-phase modulation (SPM) effect. The extinction ratio of this all-optical bidirectional switch is higher than 6dB. This compact structure may be used in the photonic integrated circuits, (PICs).