Abstract-Terahertz topological photonics for on-chip communication

Xiongbin Yu, Prakash Pitchappa, Julian Webber, Baile Zhang, Masayuki Fujita, Tadao Nagatsuma, Ranjan Singh



https://www.nature.com/articles/s41566-020-0618-9

The realization of integrated, low-cost and efficient solutions for high-speed, on-chip communication requires terahertz-frequency waveguides and has great potential for information and communication technologies, including sixth-generation (6G) wireless communication, terahertz integrated circuits, and interconnects for intrachip and interchip communication. However, conventional approaches to terahertz waveguiding suffer from sensitivity to defects and sharp bends. Here, building on the topological phase of light, we experimentally demonstrate robust terahertz topological valley transport through several sharp bends on the all-silicon chip. The valley kink states are excellent information carriers owing to their robustness, single-mode propagation and linear dispersion. By leveraging such states, we demonstrate error-free communication through a highly twisted domain wall at an unprecedented data transfer rate (exceeding ten gigabits per second) that enables real-time transmission of uncompressed 4K high-definition video (that is, with a horizontal display resolution of approximately 4,000 pixels). Terahertz communication with topological devices opens a route towards terabit-per-second datalinks that could enable artificial intelligence and cloud-based technologies, including autonomous driving, healthcare, precision manufacturing and holographic communication.

Abstract-Simultaneous low-loss and low-dispersion in a photonic-crystal waveguide for terahertz communications

Xiongbin Yu, Masaki Sugeta, Yuichiro Yamagami, Masayuki Fujita and Tadao Nagatsuma

http://iopscience.iop.org/article/10.7567/1882-0786/aaf4b3/meta

Conventional photonic-crystal waveguides make use of an equilateral triangular lattice of through holes, here we develop an isosceles triangular lattice photonic-crystal waveguide based on a silicon slab at 0.3 terahertz (THz) band, for THz high-speed communications. The propagation loss of the proposed waveguide is as small as ~1/10, compared with that of a conventional waveguide under the conditions of broadband bandwidth (>20 GHz) for both the loss and dispersion, due to the broadband low-dispersion below the light line of air, at which low-loss conditions are satisfied. Finally, we demonstrate 36 Gbit s−1 error-free THz communications using the isosceles triangular lattice photonic-crystal waveguide.