High Transmission in 120-degree Sharp Bends of Inversion-symmetric and Inversion-asymmetric Photonic Crystal Waveguides
arXiv:2310.17487 · doi:10.1038/s41467-025-56020-8
Abstract
Bending loss is one of the serious problems for constructing nanophotonic integrated circuits. Recently, many works reported that valley photonic crystals (VPhCs) enable significantly high transmission via 120-degree sharp bends. However, it is unclear whether the high bend-transmission results directly from the valley-photonic effects, which are based on the breaking of inversion symmetry. In this study, we conduct a series of comparative numerical and experimental investigations of bend-transmission in various triangular PhCs with and without inversion symmetry and reveal that the high bend-transmission is solely determined by the domain-wall configuration and independent of the existence of the inversion symmetry. Preliminary analysis of the polarization distribution indicates that high bend-transmissions are closely related to the appearance of local topological polarization singularities near the bending section. Our work demonstrates that high transmission can be achieved in a much wider family of PhC waveguides, which may provide novel designs for low-loss nanophotonic integrated circuits with enhanced flexibility and a new understanding of the nature of valley-photonics
15 pages, 7 figures, and 1 table & Supplementary information (18 pages, 15 figures and 1 table). Submitted to Nature Communication
References in corpus (5)
- The Valley Hall Effect in MoS2 Transistors
- Analogs of quantum Hall effect edge states in photonic crystals
- Observation of strong backscattering in valley-Hall photonic topological interface modes
- Experimental demonstration of topological slow light waveguides in valley photonic crystals
- GaAs valley photonic crystal waveguide with light-emitting InAs quantum dots