{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:43:50Z","timestamp":1760147030598,"version":"build-2065373602"},"reference-count":43,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2023,1,2]],"date-time":"2023-01-02T00:00:00Z","timestamp":1672617600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003141","name":"Consejo Nacional de Ciencia y Tecnolog\u00eda","doi-asserted-by":"publisher","award":["CB2016-286368","CB2017-2018-A1-S-31806","CF2019-102963","CIIC-088\/2022","CIIC-241\/2022"],"award-info":[{"award-number":["CB2016-286368","CB2017-2018-A1-S-31806","CF2019-102963","CIIC-088\/2022","CIIC-241\/2022"]}],"id":[{"id":"10.13039\/501100003141","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100006054","name":"Universidad de Guanajuato","doi-asserted-by":"publisher","award":["CB2016-286368","CB2017-2018-A1-S-31806","CF2019-102963","CIIC-088\/2022","CIIC-241\/2022"],"award-info":[{"award-number":["CB2016-286368","CB2017-2018-A1-S-31806","CF2019-102963","CIIC-088\/2022","CIIC-241\/2022"]}],"id":[{"id":"10.13039\/501100006054","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper, a ratiometric approach to sensing temperature variations is shown using specialty fiber optic devices. We analyzed the transmission response of cascaded segments of multicore fibers (MCFs), and dissimilar lengths were found to generate an adequate scheme for ratiometric operation. The perturbation of optical parameters in the MCFs translates to a rich spectral behavior in which some peaks increase their intensity while others decrease their intensity. Thus, by selecting opposite-behavior peaks, highly sensitive ratiometric measurements that provide robustness against spurious fluctuations can be performed. We implemented this approach using seven-core fiber (SCF) segments of 5.8 cm and 9.9 cm. To test the system\u2019s response under controlled perturbations, we heated one of the segments from ambient temperature up to 150 \u00b0C. We observed defined peaks with opposite behavior as a function of temperature. Two pairs of peaks within the interrogation window were selected to perform ratiometric calculations. Ratiometric measurements exhibited sensitivities 6\u201314 times higher than single-wavelength measurements. A similar trend with enhanced sensitivity in both peak pairs was obtained. In contrast to conventional interferometric schemes, the proposed approach does not require expensive facilities or micrometric-resolution equipment. Moreover, our approach has the potential to be realized using commercial splicers, detectors, and filters.<\/jats:p>","DOI":"10.3390\/s23010484","type":"journal-article","created":{"date-parts":[[2023,1,2]],"date-time":"2023-01-02T03:50:32Z","timestamp":1672631432000},"page":"484","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Ratiometric Temperature Sensing Using Highly Coupled Seven-Core Fibers"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8290-7591","authenticated-orcid":false,"given":"Daniel A.","family":"May-Arrioja","sequence":"first","affiliation":[{"name":"Centro de Investigaciones en \u00d3ptica, Prol. Constituci\u00f3n 607, Fracc. Reserva Loma Bonita, Aguascalientes 20200, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Miguel A.","family":"Fuentes-Fuentes","sequence":"additional","affiliation":[{"name":"Coordinaci\u00f3n de Matem\u00e1ticas, Universidad Tecnol\u00f3gica de Aguascalientes, Blvd. Juan Pablo II 1302 Exhacienda la Cantera, Aguascalientes 20200, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9940-2189","authenticated-orcid":false,"given":"Iv\u00e1n","family":"Hern\u00e1ndez-Romano","sequence":"additional","affiliation":[{"name":"CONACyT-Electronics Department, Sede Palo Blanco, University of Guanajuato, Carr. Salamanca-Valle de Santiago Km 3.5 + 1.8, Salamanca 36885, M\u00e9xico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rodolfo","family":"Mart\u00ednez-Manuel","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones en \u00d3ptica, Prol. Constituci\u00f3n 607, Fracc. Reserva Loma Bonita, Aguascalientes 20200, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Natanael","family":"Cuando-Espitia","sequence":"additional","affiliation":[{"name":"CONACyT-Electronics Department, Sede Palo Blanco, University of Guanajuato, Carr. Salamanca-Valle de Santiago Km 3.5 + 1.8, Salamanca 36885, M\u00e9xico"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,2]]},"reference":[{"doi-asserted-by":"crossref","unstructured":"Zhao, Z., Dang, Y., and Tang, M. (2022). Advances in Multicore Fiber Grating Sensors. Photonics, 9.","key":"ref_1","DOI":"10.3390\/photonics9060381"},{"doi-asserted-by":"crossref","unstructured":"Rajan, G., and Iniewski, K.K. (2017). Optical fiber sensors: Advanced techniques and applications. 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