All-optical logic gates based on anomalous Floquet photonic topological insulator structures

Topological photonics is an incipient research area where the well-developed theory and applications of so-called topological insulators is applied to photonic systems. In that vein, specially-designed ring waveguides, arranged in a periodic structure and evanescently coupled, have shown the ability to propagate edge states that are robust against defects in the lattice. Here, we propose the application of photonic topologically-protected edge states (TPES) in the anomalous Floquet photonic topological insulator structures to develop a device that is able to behave as OR, AND, and XOR logic gates, depending on the characteristics of the excitation field. Materials and dimensions of the device are amenable to conventional fabrication methods, opening the possibility for implementation in on-chip photonic communication technology. We conclude by applying our results to the implementation of an all-optical two bit calculator based on TPES, a potential building block for future computational technology.