Y-shaped beam splitter with topologically protected defect waveguide

The exotic properties of topological photonic crystals (PCs) have a series of application prospects in the field of optical communication. We present a Y-shaped beam splitter based on topologically protected waveguide, which consists of the topologically trivial PCs with line defect. The investigation results indicate it has the merits of unidirectional propagation, robustness, and excellent transmission performance. Compared with magnetic-optical PC beam splitter, the proposed configuration composed of rods with silicon material that can realize topological beam-splitting effect in the absence of external magnetic field and has a smaller size. It is suitable for miniaturization to implement in all-optical network as an optical communication device.