Terahertz Hybrid Topological Chip for 10-Gbps Full-Duplex Communications

Terahertz photonic chips play an important role in next-generation information systems, such as high-speed inter/intrachip connections. Here we report a hybrid hollow-core terahertz topological planar waveguide where topological silicon pillars (assembled as expanded and compressed hexagonal clusters) are sandwiched between parallel gold plates. Assisted by numerical optimization of topological waveguide unit cells and supercells, we achieve a wide topological bandgap (relative bandwidth of 16.1%) in which two low-loss (below 0.1 dB/mm) topological pseudospin states exist and cover 81.8% of the bandgap. The dual unidirectional channel in a single waveguide path can be used for short-range (below 100 mm) 10-Gbps full-duplex on-chip transmissions under the forward error correction limit (bit error rate less than 10−3). Simulation results reveal that the communication performance of the proposed topological waveguide is largely group velocity dispersion dependent. This work may pave an avenue for high-speed integrated circuit design and applications in both electric and photonic fields.