{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T07:34:56Z","timestamp":1772696096505,"version":"3.50.1"},"reference-count":34,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2022,2,25]],"date-time":"2022-02-25T00:00:00Z","timestamp":1645747200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100016804","name":"Shenzhen Natural Science Foundation","doi-asserted-by":"publisher","award":["JCYJ20200109142010888"],"award-info":[{"award-number":["JCYJ20200109142010888"]}],"id":[{"id":"10.13039\/100016804","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Research Grants Council of Hong Kong","award":["GRF15211317"],"award-info":[{"award-number":["GRF15211317"]}]},{"name":"National Key R&amp;D Program of China","award":["2018YFB1800902"],"award-info":[{"award-number":["2018YFB1800902"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>With the widespread use of few-mode fibers, mode characteristics testing becomes essential. In this paper, current few-mode fiber testing techniques are discussed, and the S2 imaging technique is chosen and demonstrated to be capable of few-mode fiber characterization in principle. As a result, the few-mode fiber characterization system with the S2 imaging technique is built and used to obtain accurate mode dispersion of two-mode fibers (a commonly used few-mode fiber) of different lengths. Then, various filters are applied to extract the fundamental and high-order modes to acquire mode coupling components (discrete and distributed mode coupling). The proposed system spectrally characterizes the few-mode fiber by resolving the interference information from the superimposed optical field spatially and has a simple structure and easy operation, which will provide parameter guidance for FMF designing and the FMF sensing experiment optimizing.<\/jats:p>","DOI":"10.3390\/s22051809","type":"journal-article","created":{"date-parts":[[2022,2,27]],"date-time":"2022-02-27T20:48:33Z","timestamp":1645994913000},"page":"1809","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Few-Mode Fiber Characterization System Based on the Spatially and Spectrally Imaging Technique"],"prefix":"10.3390","volume":"22","author":[{"given":"Jianxun","family":"Yu","sequence":"first","affiliation":[{"name":"Photonics Research Centre, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fengze","family":"Tan","sequence":"additional","affiliation":[{"name":"The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3185-0441","authenticated-orcid":false,"given":"Changyuan","family":"Yu","sequence":"additional","affiliation":[{"name":"Photonics Research Centre, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hong Kong, China"},{"name":"The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2668","DOI":"10.1364\/OE.20.002668","article-title":"Mode-division multiplexed transmission with inline few-mode fiber amplifier","volume":"20","author":"Bai","year":"2012","journal-title":"Opt. 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