Fig. 1. （a） Schematic diagram of all-dielectric valley photonic crystal structure based on elliptical lattice. Silicon and silicon dioxide are gray and blue， respectively. The incident light enters from the left waveguide， propagates along the valley photonic crystal waveguide （red） with valley Hall effect， and exits from the right waveguide， （b） Schematic diagram of unit cell structure of the valley photonic crystal VPC‖+ ， （c） Photonic band structure of TE mode of VPC‖ and VPC‖+ ， （d） Photonic band structure of TE mode of VPC⊥ and VPC⊥+， （e） The electric field intensity distributions of left-handed circular polarized （LCP） and right-handed circular polarized （RCP） light sources in the center of the dielectric column in VPC‖+ ， where LCP light propagates along the K direction， while RCP light propagates along the K’ direction， （f） The electric field intensity distributions of left-handed circular polarized （LCP） and right-handed circular polarized （RCP） light sources in the center of the dielectric column in VPC⊥+ ， where LCP light propagates along the K direction， while RCP light propagates along the K’ direction. The directions of K and K’ in the figure are indicated by white arrows.

Fig. 2. （a） The supercell structure composed of VPC‖+ and VPC‖-. The upper and lower sides are four periods of VPC‖+ and VPC‖-， （b） The photonic band diagram of the supercell structure composed of VPC‖+ and VPC‖-， （c） The electric field intensity distributions of LCP and RCP light sources placed at the center of the supercell structure （the interface between VPC‖+ and VPC‖-）， respectively， （d） The supercell structure composed of VPC⊥+ and VPC⊥-. The upper and lower sides are four periods of VPC⊥+ and VPC⊥-， （e） The photonic band diagram of the supercell structure composed of VPC⊥+ and VPC⊥-， （f） The electric field intensity distributions of LCP and RCP light sources placed at the center of the supercell structure （the interface between VPC⊥+ and VPC⊥-）， respectively， （g） Plots of forward and backward transmittance of the structure composed of VPC‖+ and VPC‖-， and the contrast ratio， （h） Plots of forward and backward transmittance of the structure composed of VPC⊥+ and VPC⊥-， and the contrast ratio

Fig. 3. （a） An Ω-shape topological optical waveguide composed of VPC‖+ and VPC‖-， and the electric field intensity distributions of light propagating along the Ω-shape optical waveguide， （b） A straight topological optical waveguide composed of VPC‖+ and VPC‖-， and the electric field intensity distributions along the straight topological optical waveguide， （c） A straight topological optical waveguide with a point defect， and the electric field intensity distributions of light propagating along the defective waveguide， （d） An Ω-shape topological optical waveguide composed of VPC⊥+ and VPC⊥-， and the electric field intensity distributions of light propagating along the Ω-shape optical waveguide， （e） A straight topological optical waveguide composed of VPC⊥+ and VPC⊥-， and the electric field intensity distributions along the straight topological optical waveguide， （f） A straight topological optical waveguide with a point defect， and the electric field intensity distributions of light propagating along the defective waveguide. The point defects are marked by the rectangle， （g） Plots of the forward transmittance of the topological optical waveguide composed of VPC‖+ and VPC‖-. Ω-shape （red）， straight waveguide （blue） and defective waveguide （black）. The gray area represents the wavelength region of the photonic bandgap， （h） Plots of the forward transmittance of the topological optical waveguide composed of VPC⊥+ and VPC⊥-. Ω-shape （red）， straight waveguide （blue） and defective waveguide （black）. The gray area represents the wavelength region of the photonic bandgap， （i） Forward transmittance plots of the Ω-shaped waveguide composed of VPC‖+ and VPC‖- and composed of VPC⊥+ and VPC⊥-， respectively， for comparison.