Towards 6G and Topological Valley Photonics for THz coherent communications

I) Increasing demand for high-capacity wireless communication requires data links at terahertz frequencies. Starting from optical devices, we develop ultra-high rate coherent communications for 6G applications. Concurrently, topological phases revolutionized wave transport, enabling integrated photonic interconnects with sharp light bending on a chip, paving the way for a new components generation.

In collaboration with IEMN and the Microelectronics Research Center (Univiversity of Texas, Austin), we characterized a THz switch made from 2D materials (one or two atomic layers thick). The results show a cutoff of more than 15 dB and very good transmission behavior up to 100 GB/s when the switch is ON. This work is published in Nature Electronics 5, 367 (2022). It was the subject of a “research briefing”: Nature Electronics 5, 331 (2022).

II) In collaboration with IEMN and Nanyang Technological University (Singapore). We demonstrate a new class of phototunable, on-chip topological terahertz devices consisting of a broadband single-channel 160 Gbit/s communication link and a silicon Valley Photonic Crystal based demultiplexer. The optically controllable demultiplexing of two different carriers modulated signals without crosstalk is enabled by the topological protection and a critically coupled highquality (Q) cavity. As a proof of concept, we demultiplexed high spectral efficiency 40 Gbit/s signals and demonstrated real-time streaming of uncompressed high-definition (HD) video (1.5 Gbit/s) using the topological photonic chip. Published in Nature Communications 13, 5404 (2022), according Web of Science, this work is a “hot paper”, cited in the top 0.1% of papers in the academic field of Physics.