Fig. 1. Schematic of lattice structure and minimum distance of structure

Fig. 2. Supercell band structure

Fig. 3. Energy band range and bandwidth change

Fig. 4. 3D structures of straight waveguide and“Z”shaped waveguide

Fig. 5. Band structure of different unit cells

Fig. 6. Variation of band gap and band gap width of unit cells with different triangular side lengths

Fig. 7. Intrinsic phase image

Fig. 8. Energy band and electric field distribution of superlattice structure of triangular lattice valley photonic crystal

Fig. 9. Straight-line transmission electric field diagram and normalized output power

Fig. 10. “Z”shaped transmission electric field diagram and normalized output power