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arXiv · 2510.17069

Beyond 350 GHz: Single-channel 112 Gbps photonic wireless transmission at 560 GHz using soliton microcombs

Yu Tokizane·Hiroki Kishikawa·Takumi Kikuhara·Miezel Talara·Yoshihiro Makimoto·Kodai Yamaji Yasuhiro Okamura·Kenji Nishimoto·Eiji Hase·Isao Morohashi·Atsushi Kanno·Shintaro Hisatake·Naoya Kuse·Tadao Nagatsuma·Takeshi Yasui
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Abstract

Sixth-generation (6G) back-haul links will require terahertz (THz) carriers above 350 GHz to escape the congested 300 GHz band and support >100 Gbps data rates. Photonic THz transmitters have so far remained below 350 GHz because high-frequency photomixing suffers from phase noise and power limits. Here we demonstrate single-channel wireless transmission at 560 GHz using a fibre-packaged silicon-nitride soliton microcomb as a compact, low-phase-noise optical reference. A high numerical aperture, UV-bonded fibre interface sustains soliton operation for more than 24 hours with 1 W pump power. We phase-lock two distributed-feedback lasers (DFBs) to adjacent comb lines and photomix them in a high-power uni-travelling-carrier photodiode, generating a 560 GHz carrier that bears in-phase and quadrature modulation. We achieve hard-decision forward-error-correction-qualified quadrature phase-shift keying and 16-quadrature amplitude modulation (16QAM) transmissions at 42 and 28 GBaud, respectively, attaining a record 112 Gbps data rate at 560 GHz. Relative to free-running DFBs, microcomb-locked photomixing cuts carrier linewidth and improves 16QAM error-vector magnitude. The results establish soliton microcombs as compact and scalable frequency references for >100 Gbps sub-THz links and chart a path toward compact 6 G back-haul radios.

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Yu Tokizane, Hiroki Kishikawa, Takumi Kikuhara, Miezel Talara, Yoshihiro Makimoto, Kodai Yamaji Yasuhiro Okamura, Kenji Nishimoto, Eiji Hase, Isao Morohashi, Atsushi Kanno, Shintaro Hisatake, Naoya Kuse, Tadao Nagatsuma, Takeshi Yasui. 2025-10-20. Beyond 350 GHz: Single-channel 112 Gbps photonic wireless transmission at 560 GHz using soliton microcombs. https://doi.org/10.1038/s44172-026-00659-8

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