On-chip amorphous terahertz topological photonic interconnects
Rimi Banerjee, Abhishek Kumar, Thomas Caiwei Tan, Manoj Gupta, Ridong Jia, Pascal Szriftgiser, Guillaume Ducournau, Y. D. Chong, Ranjan Singh
Abstract
Valley Hall photonic crystals (VPCs) offer the potential for creating topological waveguides capable of guiding light through sharp bends on a chip, enabling seamless integration with functional components in compact spaces, making them a promising technology for terahertz topological photonic integrated circuits. However, a key limitation for terahertz-scale integrated VPC-based devices has been the absence of arbitrary bend interconnects, as traditional VPC-designs restricted to principal lattice axes (i.e., only 0°, 60°, or 120°) due to crystalline symmetry. Here, we present an on-chip, all-silicon implementation of deformed VPCs that enable robust transmission along arbitrary shapes and bends. Although the lattice is amorphous and lacks long-range periodicity, the topological protection is sustained by short-range order. Furthermore, we show an amorphous lattice functioning as a frequency-dependent router, splitting input signals into two perpendicular output ports. We also demonstrate on-chip terahertz communication, achieving data rates of up to 72 Gbps. Our findings show that amorphous topological photonic crystals enhance interconnect adaptability while preserving performance.