{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T05:54:59Z","timestamp":1777528499912,"version":"3.51.4"},"reference-count":31,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2021,8,13]],"date-time":"2021-08-13T00:00:00Z","timestamp":1628812800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper, we propose a highly sensitive temperature sensor based on two cascaded Mach\u2013Zehnder interferometers (MZIs) that work using the Vernier effect. The all-fiber MZIs were assembled by splicing a segment of capillary hollow-core fiber (CHCF) between two sections of multimode fibers (MMFs). This cascaded configuration exhibits a temperature sensitivity of 1.964 nm\/\u00b0C in a range from 10 to 70 \u00b0C, which is ~67.03 times higher than the sensitivity of the single MZI. Moreover, this device exhibits a high-temperature resolution of 0.0153 \u00b0C. A numerical analysis was carried out to estimate the devices\u2019 temperature sensitivity and calculate the magnification of the sensitivity produced by the Vernier effect. The numerical results have an excellent agreement with the experimental results and provide a better insight into the working principle of the MZI devices. The sensor\u2019s performance, small size, and easy fabrication make us believe that it is an attractive candidate for temperature measurement in biological applications.<\/jats:p>","DOI":"10.3390\/s21165471","type":"journal-article","created":{"date-parts":[[2021,8,13]],"date-time":"2021-08-13T09:22:38Z","timestamp":1628846558000},"page":"5471","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":28,"title":["In-Line Mach\u2013Zehnder Interferometers Based on a Capillary Hollow-Core Fiber Using Vernier Effect for a Highly Sensitive Temperature Sensor"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5261-5312","authenticated-orcid":false,"given":"Sigifredo","family":"Marrujo-Garc\u00eda","sequence":"first","affiliation":[{"name":"Electronics Department, DICIS, Universidad de Guanajuato, Carretera Salamanca-Valle de Santiago km 3.5 + 1.8, Salamanca 36885, Mexico"}]},{"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, DICIS, Universidad de Guanajuato, Carretera Salamanca-Valle de Santiago km 3.5 + 1.8, Salamanca 36885, Mexico"}]},{"given":"Daniel A.","family":"May-Arrioja","sequence":"additional","affiliation":[{"name":"Fiber and Integrated Optics Laboratory (FIOLab), Centro de Investigaciones en \u00d3ptica A.C., Aguascalientes 20200, Mexico"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4168-2223","authenticated-orcid":false,"given":"Vladimir P.","family":"Minkovich","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones en \u00d3ptica A.C., Calle Loma del Bosque 115, Le\u00f3n 37150, Mexico"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2408-4945","authenticated-orcid":false,"given":"Miguel","family":"Torres-Cisneros","sequence":"additional","affiliation":[{"name":"Electronics Department, DICIS, Universidad de Guanajuato, Carretera Salamanca-Valle de Santiago km 3.5 + 1.8, Salamanca 36885, Mexico"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/j.snb.2015.11.047","article-title":"High sensitivity refractive index sensor based on splicing points tapered SMF-PCF-SMF structure Mach-Zehnder mode interferometer","volume":"225","author":"Wang","year":"2016","journal-title":"Sens. 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