{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T20:24:16Z","timestamp":1774383856935,"version":"3.50.1"},"reference-count":37,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2018,12,8]],"date-time":"2018-12-08T00:00:00Z","timestamp":1544227200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Coatings"],"abstract":"<jats:p>In this work, a relative humidity (RH) sensor based on a structure with multimode interference is proposed and experimentally demonstrated. The multimode sensor is fabricated by fusion splicing a coreless fiber section to a single mode fiber. A hydrophilic agarose gel is coated on the coreless fiber, using the dip coating technique. By changing the surrounding RH, the refractive index of the coated agarose gel will change, causing a wavelength shift of the peak in the reflection spectra. For RH variations in the range between 60.0%RH and 98.5%RH, the sensor presents a maximum sensitivity of 44.2 pm\/%RH, and taking in consideration the interrogation system, a resolution of 0.5%RH is acquired. This sensor has a great potential in real time RH monitoring and can be of interest for applications where a control of high levels of relative humidity is required.<\/jats:p>","DOI":"10.3390\/coatings8120453","type":"journal-article","created":{"date-parts":[[2018,12,10]],"date-time":"2018-12-10T03:36:41Z","timestamp":1544413001000},"page":"453","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["Relative Humidity Fiber Sensor Based on Multimode Interferometer Coated with Agarose-Gel"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8295-3259","authenticated-orcid":false,"given":"Susana","family":"Novais","sequence":"first","affiliation":[{"name":"I3N &amp; Physics Department, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1170-7530","authenticated-orcid":false,"given":"Marta S.","family":"Ferreira","sequence":"additional","affiliation":[{"name":"I3N &amp; Physics Department, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6002-1060","authenticated-orcid":false,"given":"Jo\u00e3o L.","family":"Pinto","sequence":"additional","affiliation":[{"name":"I3N &amp; Physics Department, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2018,12,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.optlastec.2015.05.006","article-title":"Humidity sensor based on optical fiber attached with hydrogel spheres","volume":"74","author":"Zhang","year":"2015","journal-title":"Opt. 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