Abstract
The advancement of integrated optical communication networks necessitates the deployment of on-chip beam splitters for efficient signal interconnections at network nodes.However,the pursuit of micron-scale beam splitting with large comers and reducing the device footprint to boost connection flexibility often results in phase mismatches.These mismatches,which stem from radiation modes and backward scattering,pose significant obstacles in creating highly integrated and interference-resistant connections.To address this,we introduce a solution based on the topological valley-contrasting state generated by photonic crystals with opposing valley Chem numbers,manifested in a harpoon-shaped structure designed to steer the splitting channels.This approach enables adiabatic mode field evolution over large comers,capitalizing on the robust phase modulation capabilities and topological protection provided by the subwavelength-scale valley-contrasting state.Our demonstration reveals that beam splitters with large corners of 60°,90°,and 120° exhibit insertion loss fluctuations below 2.7 dB while maintaining a minimal footprint of 8.8 μm × 8.8 μm.As a practical demonstration,these devices facilitate three-channel signal connections,success-fully transmitting quadrature phase shift keying signals at 3.66 Tbit/s with bit error rates below the forward error correction threshold,demonstrating performance comparable to that in defects scenarios.By harnessing the unidirectional excitation feature,we anticipate significant enhancements in the capabilities of signal distribution and connection networks through a daisy chain configuration.
基金项目
National Natural Science Foundation of China(62271322)
Guangdong Basic and Applied Basic Research Foundation(2023A1515030152)
Shenzhen Science and Technologv Program(JCYJ20210324095610027)
Natural science Foundation of Top Talent of SZTU(GDRC202204)
Qianxinan Prefecture Science and Technology Plan Project(2023123)
Scientific Research Fund Project of Minzu Normal University of Xingyi(23XYZD07)
万方数据