Design of broadband all-dielectric valley photonic crystals at telecommunication wavelength

Topological photonic crystals (TPC) can effectively suppress the backscattering from defects and achieve unidirectional transmission with high forward transmittance, thus becoming a promising candidate in integrated photonic chip applications. Among different TPCs, the valley photonic crystals (VPCs) based on quantum valley Hall effect (QVHE) originating from valley-dependent spin-split bulk bands, can achieve spin-dependent unidirectional...