Millimetre-wave comb generated by an optical microcomb
Abstract Millimetre-wave baseband combs are relevant to wireless links, sensing, and device characterisation. Direct broadband generation from an optical microcomb has remained elusive because of challenges in photoconductive conversion. Here, we demonstrate a 50 GHz repetition-rate millimetre-wave baseband comb covering the sub-THz region, generated by photoconductive conversion of a laser-cavity-soliton microcomb. The microresonator-filtered source combines low free-running phase noise and high spectral efficiency, enabling coherent conversion without additional optical amplification to single-cycle, carrier-envelope-offset-free waveforms with multiple harmonics directly observed in the converted output. The source supports free-running time-domain spectroscopy over optical path delays above 8 m, and its lines are driven by the optical repetition-rate harmonics with traceable improvement of synchronisation performance upon external locking. In addition, multisoliton operation reshapes the harmonic envelope while preserving the common line spacing, providing a simple route to source-level spectral control in the sub-THz region.
Authors
- Luke Peters (ORCID: https://orcid.org/0000-0003-0553-2965)
- F. Getman (ORCID: https://orcid.org/0000-0003-1550-0182)
- Marco Peccianti (ORCID: https://orcid.org/0000-0001-8894-496X)
- Nitish Paul (ORCID: https://orcid.org/0000-0002-5719-2467)
- Maxwell Rowley (ORCID: https://orcid.org/0000-0002-2279-2710)
- Vittorio Cecconi (ORCID: https://orcid.org/0000-0002-4054-717X)
- Antonio Cutrona (ORCID: https://orcid.org/0000-0001-5097-0724)
- Juan Sebastian Totero Gongora (ORCID: https://orcid.org/0000-0003-2300-4218)
- Luana Olivieri (ORCID: https://orcid.org/0000-0003-1729-7894)
- Alessia Pasquazi (ORCID: https://orcid.org/0000-0003-3330-584X)
- Debayan Das (ORCID: https://orcid.org/0000-0003-3066-0256)
- Andrew Cooper (ORCID: https://orcid.org/0009-0005-1810-4857)
- Brent E. Little
- David Moss
- Roberto Morandotti
Institutions
- Loughborough University (GB)
- University of Sussex (GB)
- City University of Hong Kong (HK)
- Institut National de la Recherche Scientifique (CA)
- QED Technologies (United States) (US)
- Swinburne University of Technology (AU)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-08-20
- DOI
- https://doi.org/10.1038/s41467-026-76747-2
- Primary Topic
- Advanced Fiber Laser Technologies
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Leverhulme Trust
- European Commission
- Loughborough University
- Engineering and Physical Sciences Research Council
- U.S. Army Combat Capabilities Development Command
- Army Research Office