Terahertz topological photonics for on-chip communication

TL;DR

This paper demonstrates robust terahertz topological valley transport on silicon chips, enabling high-speed, error-free on-chip communication with minimal losses even through sharp bends, advancing THz communication technology.

Contribution

It provides the first experimental demonstration of topological phases of THz waves on silicon chips, showcasing robust valley transport for high-speed on-chip data transmission.

Findings

Unity transmission over a bulk band gap after ten sharp corners

Error-free data transmission at 10 Gbit/s

Successful uncompressed 4K video transmission

Abstract

The computing speeds in modern multi-core processors and big data servers are no longer limited by the on-chip transistor density that doubles every two years following the Moores law, but are limited by the on-chip data communication between memories and microprocessor cores. Realization of integrated, low-cost, and efficient solutions for high speed, on-chip data communications require terahertz (THz) interconnect waveguides with tremendous significance in future THz technology including THz-wave integrated circuits and THz communication. However, conventional approaches to THz waveguiding suffer from sensitivity to defects and considerable bending losses at sharp bends. Here, building on the recently-discovered topological phase of light, we experimentally demonstrate robust THz topological valley transport on low-loss, all-silicon chips. We show that the valley polarized topological kink states exhibit unity transmission over a bulk band gap even after propagating through ten sharp corners. Such states are excellent information carriers due to their robustness, single-mode propagation, and linear dispersion-key properties for next generation THz communications. By leveraging the unique properties of kink states, we demonstrate error-free communication through a highly-twisted domain wall at an unprecedented data rate (10 Gbit/s) and uncompressed 4K high-definition video transmission. Our work provides the first experimental demonstration of the topological phases of THz wave, which could certainly inspire a plethora of research on different types of topological phases in two and three dimensions.