{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T19:39:36Z","timestamp":1784144376744,"version":"3.55.0"},"reference-count":43,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2020,8,10]],"date-time":"2020-08-10T00:00:00Z","timestamp":1597017600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"FINESSE","award":["MSCA-ITN-ETN-722509"],"award-info":[{"award-number":["MSCA-ITN-ETN-722509"]}]},{"name":"Spanish Ministerio de Ciencia, Innovaci\u00f3n y Universidades","award":["RTI2018-097957-B-C31"],"award-info":[{"award-number":["RTI2018-097957-B-C31"]}]},{"name":"Spanish Ministerio de Ciencia, Innovaci\u00f3n y Universidades","award":["RTI2018-097957-B-C33"],"award-info":[{"award-number":["RTI2018-097957-B-C33"]}]},{"name":"Comunidad de Madrid and FEDER program","award":["SINFOTON2-CM: P2018\/NMT-4326"],"award-info":[{"award-number":["SINFOTON2-CM: P2018\/NMT-4326"]}]},{"DOI":"10.13039\/501100000781","name":"European Research Council","doi-asserted-by":"publisher","award":["OCEAN-DAS: ERC-2019-POC-875302"],"award-info":[{"award-number":["OCEAN-DAS: ERC-2019-POC-875302"]}],"id":[{"id":"10.13039\/501100000781","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Spanish MINECO","award":["IJCI-2017-33856"],"award-info":[{"award-number":["IJCI-2017-33856"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Nowadays there is an increasing demand for the cost-effective monitoring of potential threats to the integrity of high-voltage networks and electric power infrastructures. Optical fiber sensors are a particularly interesting solution for applications in these environments, due to their low cost and positive intrinsic features, including small size and weight, dielectric properties, and invulnerability to electromagnetic interference (EMI). However, due precisely to their intrinsic EMI-immune nature, the development of a distributed optical fiber sensing solution for the detection of partial discharges and external electrical fields is in principle very challenging. Here, we propose a method to exploit the third-order and second-order nonlinear effects in silica fibers, as a means to achieve highly sensitive distributed measurements of external electrical fields in real time. By monitoring the electric-field-induced variations in the refractive index using a highly sensitive Rayleigh-based CP-\u03c6OTDR scheme, we demonstrate the distributed detection of Kerr and Pockels electro-optic effects, and how those can assign a new sensing dimension to optical fibers, transducing external electric fields into visible minute disturbances in the guided light. The proposed sensing configuration, electro-optical time domain reflectometry, is validated both theoretically and experimentally, showing experimental second-order and third-order nonlinear coefficients, respectively, of \u03c7(2) ~ 0.27 \u00d7 10\u221212 m\/V and \u03c7(3) ~ 2.5 \u00d7 10\u221222 m2\/V2 for silica fibers.<\/jats:p>","DOI":"10.3390\/s20164461","type":"journal-article","created":{"date-parts":[[2020,8,10]],"date-time":"2020-08-10T07:25:03Z","timestamp":1597044303000},"page":"4461","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Towards Distributed Measurements of Electric Fields Using Optical Fibers: Proposal and Proof-Of-Concept Experiment"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4666-0840","authenticated-orcid":false,"given":"Regina","family":"Magalh\u00e3es","sequence":"first","affiliation":[{"name":"Departamento de Electr\u00f3nica, Universidad de Alcal\u00e1, 28805 Alcal\u00e1 de Henares, Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8673-2880","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Pereira","sequence":"additional","affiliation":[{"name":"RISE Research Institutes of Sweden, Electrum 236, 16440 Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oleksandr","family":"Tarasenko","sequence":"additional","affiliation":[{"name":"RISE Research Institutes of Sweden, Electrum 236, 16440 Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sonia","family":"Martin-Lopez","sequence":"additional","affiliation":[{"name":"Departamento de Electr\u00f3nica, Universidad de Alcal\u00e1, 28805 Alcal\u00e1 de Henares, Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miguel","family":"Gonz\u00e1lez-Herr\u00e1ez","sequence":"additional","affiliation":[{"name":"Departamento de Electr\u00f3nica, Universidad de Alcal\u00e1, 28805 Alcal\u00e1 de Henares, Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Walter","family":"Margulis","sequence":"additional","affiliation":[{"name":"RISE Research Institutes of Sweden, Electrum 236, 16440 Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3927-8125","authenticated-orcid":false,"given":"Hugo","family":"Fidalgo Martins","sequence":"additional","affiliation":[{"name":"Instituto de \u00d3ptica, Consejo Superior de Investigaciones Cient\u00edficas, 28006 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"King, R.L. 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