Dynamics and transport properties of Floquet topological edge modes in coupled photonic waveguides

We study theoretically the Floquet edge states in a photonic analog of the driven Su-Schrieffer-Heeger model implemented by an array of identical single-mode dielectric waveguides, where the time-dependent driving is modeled by periodically bended waveguides. We combine the coupled-mode theory with the Floquet-Bloch analysis and within this framework determine a band structure of the periodic system. We develop a theoretical approach for calculation of the edge states in semi-infinite systems and investigate their topological properties. In particular, we explore the dynamics of the 0- and pi-edge states which reveal profound differences depending on their topological phase. To verify our observations, we simulate the power transport along the end of such a waveguide array and show that its spectra can be assigned to the excitation of the edge modes. The results obtained indicate that driving-induced topological properties of the edge modes can be exploited in controlling flow of light in periodically driven photonic structures and may provide insight into Floquet engineering of the realistic photonic systems.