{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,17]],"date-time":"2026-04-17T15:57:44Z","timestamp":1776441464061,"version":"3.51.2"},"reference-count":37,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2019,4,6]],"date-time":"2019-04-06T00:00:00Z","timestamp":1554508800000},"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>A Mach-Zehnder interferometer (MZI) based fiberoptic refractive index (RI) sensor is constructed by uniformly tapering standard single mode fiber (SMF) for RI measurement. A custom flame-based tapering machine is used to fabricate microfiber MZI sensors directly from SMFs. The fabricated MZI device does not require any splicing of fibers and shows excellent RI sensitivity. The sensor with a cladding diameter of 35.5 \u00b5m and length of 20 mm exhibits RI sensitivity of 415 nm\/RIU for RI range of 1.332 to 1.384, 1103 nm\/RIU for RI range of 1.384 to 1.4204 and 4234 nm\/RIU for RI range of 1.4204 to 1.4408, respectively. The sensor reveals a temperature sensitivity of 0.0097 nm\/\u00b0C, which is relatively low in comparison to its ultra-high RI sensitivity. The proposed inexpensive and highly sensitive optical fiber RI sensors have numerous applications in chemical and biochemical sensing fields.<\/jats:p>","DOI":"10.3390\/s19071652","type":"journal-article","created":{"date-parts":[[2019,4,8]],"date-time":"2019-04-08T11:54:52Z","timestamp":1554724492000},"page":"1652","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":113,"title":["Tapered Fiber-Optic Mach-Zehnder Interferometer for Ultra-High Sensitivity Measurement of Refractive Index"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8115-5877","authenticated-orcid":false,"given":"Vahid","family":"Ahsani","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5307-6960","authenticated-orcid":false,"given":"Farid","family":"Ahmed","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0512-7209","authenticated-orcid":false,"given":"Martin B.G.","family":"Jun","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada"},{"name":"School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Colin","family":"Bradley","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,4,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1021\/acs.analchem.5b04298","article-title":"Fiber-Optic Chemical Sensors and Biosensors (2013\u20132015)","volume":"88","author":"Wang","year":"2016","journal-title":"Anal. 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