eprintid: 10055090 rev_number: 21 eprint_status: archive userid: 608 dir: disk0/10/05/50/90 datestamp: 2018-08-30 10:26:55 lastmod: 2021-10-09 23:03:44 status_changed: 2018-08-30 10:26:55 type: article metadata_visibility: show creators_name: Liu, Z creators_name: Kakande, J creators_name: Kelly, B creators_name: O'Carroll, J creators_name: Phelan, R creators_name: Richardson, DJ creators_name: Slavik, R title: Modulator-free quadrature amplitude modulation signal synthesis ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F46 note: This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ abstract: The ability to generate high-speed on–off-keyed telecommunication signals by directly modulating a semiconductor laser’s drive current was one of the most exciting prospective applications of the nascent field of laser technology throughout the 1960s. Three decades of progress led to the commercialization of 2.5 Gbit s−1-per-channel submarine fibre optic systems that drove the growth of the internet as a global phenomenon. However, the detrimental frequency chirp associated with direct modulation forced industry to use external electro-optic modulators to deliver the next generation of on–off-keyed 10 Gbit s−1 systems and is absolutely prohibitive for today’s (>)100 Gbit s−1 coherent systems, which use complex modulation formats (for example, quadrature amplitude modulation). Here we use optical injection locking of directly modulated semiconductor lasers to generate complex modulation format signals showing distinct advantages over current and other currently researched solutions. date: 2014 date_type: published publisher: NATURE PUBLISHING GROUP official_url: https://doi.org/10.1038/ncomms6911 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green article_type_text: Article verified: verified_manual elements_id: 1195292 doi: 10.1038/ncomms6911 lyricists_name: Liu, Zhixin lyricists_id: ZLIUB50 actors_name: Flynn, Bernadette actors_id: BFFLY94 actors_role: owner full_text_status: public publication: Nature Communications volume: 5 article_number: 5911 pages: 7 issn: 2041-1723 citation: Liu, Z; Kakande, J; Kelly, B; O'Carroll, J; Phelan, R; Richardson, DJ; Slavik, R; (2014) Modulator-free quadrature amplitude modulation signal synthesis. Nature Communications , 5 , Article 5911. 10.1038/ncomms6911 <https://doi.org/10.1038/ncomms6911>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10055090/1/Liu_ncomms6911.pdf document_url: https://discovery.ucl.ac.uk/id/eprint/10055090/8/Liu_ncomms6911-s1.pdf