Tunable All-Optical Diode Based on a Coupled System of Two Nonsymmetrical Cavities and a Metal Film

To obtain an optimal and tunable all-optical diode behavior, we design a coupled system as all-optical diode which is composed of two nonsynnmetrical cavities and a metal film. We study the transmission properties of the diode through the nonlinear transfer matrix method. We design four structure models and use four characteristic parameters to describe the performance of the diodes. The performance of the all-optical diode is dependent on the relative position and ratio of thickness of the two cavities as well as the thickness of the metal. The two cavities with a smaller difference of thickness result in smaller threshold incidence energy, but also a smaller unidirectional transmission effect. The metal thickness determines the switch direction of the diode. The results provide us a big space to optimize the design of all-optical diode.