{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:32:51Z","timestamp":1760243571022,"version":"build-2065373602"},"reference-count":21,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2013,8,23]],"date-time":"2013-08-23T00:00:00Z","timestamp":1377216000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We report an easy-to-build, compact, and low-cost optical fiber refractive index sensor. It consists of a single fiber loop whose transmission spectra exhibit a series of notches produced by the resonant coupling between the fundamental mode and the cladding modes in a uniformly bent fiber. The wavelength of the notches, distributed in a wavelength span from 1,400 to 1,700 nm, can be tuned by adjusting the diameter of the fiber loop and are sensitive to refractive index changes of the external medium. Sensitivities of 170 and 800 nm per refractive index unit for water solutions and for the refractive index interval 1.40\u20131.442, respectively, are demonstrated. We estimate a long range resolution of 3 \u00d7 10\u22124 and a short range resolution of 2 \u00d7 10\u22125 for water solutions.<\/jats:p>","DOI":"10.3390\/s130911260","type":"journal-article","created":{"date-parts":[[2013,8,23]],"date-time":"2013-08-23T11:38:05Z","timestamp":1377257885000},"page":"11260-11270","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["A Refractive Index Sensor Based on the Resonant Coupling to Cladding Modes in a Fiber Loop"],"prefix":"10.3390","volume":"13","author":[{"given":"Mauricio","family":"Reyes","sequence":"first","affiliation":[{"name":"Departamento de F\u00edsica Aplicada, Instituto de Ciencia de los Materiales, Universidad de Valencia, Burjassot 46100, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David","family":"Monz\u00f3n-Hern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Grupo de Sensores \u00d3pticos y Microdispositivos, Centro de Investigaciones en \u00d3ptica A.C.,  Loma del Bosque 115, col. Lomas del Campestre, Leon, Guanajuato 37150, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alejandro","family":"Mart\u00ednez-R\u00edos","sequence":"additional","affiliation":[{"name":"Grupo de Sensores \u00d3pticos y Microdispositivos, Centro de Investigaciones en \u00d3ptica A.C.,  Loma del Bosque 115, col. Lomas del Campestre, Leon, Guanajuato 37150, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4092-8597","authenticated-orcid":false,"given":"Enrique","family":"Silvestre","sequence":"additional","affiliation":[{"name":"Departamento de \u00d3ptica, Universidad de Valencia, Burjassot 46100, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Antonio","family":"D\u00edez","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica Aplicada, Instituto de Ciencia de los Materiales, Universidad de Valencia, Burjassot 46100, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jos\u00e9","family":"Cruz","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica Aplicada, Instituto de Ciencia de los Materiales, Universidad de Valencia, Burjassot 46100, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Miguel","family":"Andr\u00e9s","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica Aplicada, Instituto de Ciencia de los Materiales, Universidad de Valencia, Burjassot 46100, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2013,8,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1946","DOI":"10.1109\/LPT.2007.908777","article-title":"A highly sensitive fiber-optic refractive index sensor based on an edge-written long-period fiber grating","volume":"19","author":"Zhu","year":"2007","journal-title":"IEEE Photon. 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