Antichiral-like and antichiral edge states based on photonic Floquet lattices

Photonic Floquet lattices provide an excellent platform for manipulating different topologically protected edge states. However, antichiral edge states have not been discussed much in Floquet lattices. Here, we propose a waveguide structure composed of two honeycomb Floquet photonic lattices rotating in opposite directions and find that the edge states propagate in the same direction on two opposite parallel zigzag boundaries of the system, thus achieving antichiral-like edge states. Furthermore, we propose a method to achieve smooth transition of the system without the artificial internal interface, thus eliminating the internal interface of the system, forming two co-propagating one-way transport channels at the system boundary, and discovering the antichiral edge states which are completely different from the well-studied topological edge states of chiral photonic systems. The long-distance propagation dynamics of the corresponding boundary states are numerically studied by comparing the intensity mode. In addition to their relevance for the topological properties of the Floquet lattice system, the results of this study may be applied to multi-channel optical switches, optical functional devices and other fields.