{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,21]],"date-time":"2025-10-21T15:25:41Z","timestamp":1761060341820,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2017,4,29]],"date-time":"2017-04-29T00:00:00Z","timestamp":1493424000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish Economy and Competitiveness Ministry","award":["TEC2016-79367-C2-2-R","TEC-2013- 43679-R"],"award-info":[{"award-number":["TEC2016-79367-C2-2-R","TEC-2013- 43679-R"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The refractive index of sputtered indium oxide nanocoatings has been altered just by changing the sputtering parameters, such as pressure. These induced changes have been exploited for the generation of a grating on the end facet of an optical fiber towards the development of wavelength-modulated optical fiber humidity sensors. A theoretical analysis has also been performed in order to study the different parameters involved in the fabrication of this optical structure and how they would affect the sensitivity of these devices. Experimental and theoretical results are in good agreement. A sensitivity of 150 pm\/%RH was obtained for relative humidity changes from 20% to 60%. This kind of humidity sensors shows a maximum hysteresis of 1.3% relative humidity.<\/jats:p>","DOI":"10.3390\/s17050991","type":"journal-article","created":{"date-parts":[[2017,5,2]],"date-time":"2017-05-02T11:37:20Z","timestamp":1493725040000},"page":"991","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Humidity Sensor Based on Bragg Gratings Developed on the End Facet of an Optical Fiber by Sputtering of One Single Material"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0304-3394","authenticated-orcid":false,"given":"Joaquin","family":"Ascorbe","sequence":"first","affiliation":[{"name":"Department of Electrical and Electronic Engineering, Public University of Navarra, Pamplona 31006, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1298-5700","authenticated-orcid":false,"given":"Jesus","family":"Corres","sequence":"additional","affiliation":[{"name":"Institute of Smart Cities, Public University of Navarra, Pamplona 31006, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3311-0834","authenticated-orcid":false,"given":"Francisco","family":"Arregui","sequence":"additional","affiliation":[{"name":"Institute of Smart Cities, Public University of Navarra, Pamplona 31006, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2229-6178","authenticated-orcid":false,"given":"Ignacio","family":"Matias","sequence":"additional","affiliation":[{"name":"Institute of Smart Cities, Public University of Navarra, Pamplona 31006, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,4,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1016\/j.sna.2008.04.008","article-title":"Fibre Bragg gratings in structural health monitoring-Present status and applications","volume":"147","author":"Majumder","year":"2008","journal-title":"Sens. Actuators A Phys."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.sna.2008.07.015","article-title":"Long period grating-based humidity sensor for potential structural health monitoring","volume":"148","author":"Venugopalan","year":"2008","journal-title":"Sens. Actuators A Phys."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.sna.2015.05.007","article-title":"Opto-electronic humidity sensor: A review","volume":"233","author":"Sikarwar","year":"2015","journal-title":"Sens. Actuators A Phys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1647","DOI":"10.1016\/j.engstruct.2004.05.018","article-title":"Recent applications of fiber optic sensors to health monitoring in civil engineering","volume":"26","author":"Li","year":"2004","journal-title":"Eng. Struct."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.snb.2011.06.042","article-title":"Fiber optic humidity sensors for high-energy physics applications at CERN","volume":"159","author":"Consales","year":"2011","journal-title":"Sens. Actuators B Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"4052","DOI":"10.1016\/j.measurement.2013.07.030","article-title":"Optical fibre-based sensor technology for humidity and moisture measurement: Review of recent progress","volume":"46","author":"Alwis","year":"2013","journal-title":"Meas. J. Int. Meas. Confed."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1016\/j.jfoodeng.2011.03.020","article-title":"Impact of air humidity in industrial heating processes on selected quality attributes of bread rolls","volume":"105","author":"Schirmer","year":"2011","journal-title":"J. Food Eng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/S0925-4005(00)00524-4","article-title":"Optical fiber humidity sensor based on a tapered fiber coated with agarose gel","volume":"69","author":"Bariain","year":"2000","journal-title":"Sens. Actuators B Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4127","DOI":"10.1364\/AO.43.004127","article-title":"Optical fiber relative-humidity sensor with polyvinyl alcohol film","volume":"43","author":"Gasto","year":"2004","journal-title":"Appl. Opt."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/0925-4005(96)80125-0","article-title":"Humidity-sensitive optical absorption of CO3O4 film","volume":"32","author":"Ando","year":"1996","journal-title":"Sens. Actuators B Chem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1109\/JSEN.2014.2353038","article-title":"Tapered plastic optical fiber coated with al-doped ZnO nanostructures for detecting relative humidity","volume":"15","author":"Harith","year":"2015","journal-title":"IEEE Sens. J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4702","DOI":"10.1109\/JSEN.2013.2272329","article-title":"Tapered plastic optical fiber coated with HEC\/PVDF for measurement of relative humidity","volume":"13","author":"Batumalay","year":"2013","journal-title":"IEEE Sens. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"472","DOI":"10.1109\/TMTT.1982.1131089","article-title":"Optical Fiber Sensor Technology","volume":"30","author":"Giallorenzi","year":"1982","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"12019","DOI":"10.1088\/1742-6596\/178\/1\/012019","article-title":"Optical fiber humidity sensor based on surface plasmon resonance in the infra-red region","volume":"178","author":"Matias","year":"2009","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1016\/j.snb.2003.05.001","article-title":"Nano-like magnesium oxide films and its significance in optical fiber humidity sensor","volume":"98","author":"Shukla","year":"2004","journal-title":"Sens. Actuators B Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.snb.2016.04.045","article-title":"High sensitivity humidity sensor based on cladding-etched optical fiber and lossy mode resonances","volume":"233","author":"Ascorbe","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1016\/j.snb.2010.02.029","article-title":"Tunable humidity sensor based on ITO-coated optical fiber","volume":"146","author":"Hernaez","year":"2010","journal-title":"Sens. Actuators B Chem."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/0040-6090(95)06543-1","article-title":"Sb-doped SnO2 transparent conducting oxide from the sol-gel dip-coating technique","volume":"263","author":"Terrier","year":"1995","journal-title":"Thin Solid Films"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/S0040-6090(01)00847-1","article-title":"Indium-tin-oxide thin films prepared by dip-coating of indium diacetate monohydroxide and tin dichloride","volume":"388","author":"Seki","year":"2001","journal-title":"Thin Solid Films"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1403","DOI":"10.1116\/1.576890","article-title":"Low resistivity indium\u2013tin oxide transparent conductive films. II. Effect of sputtering voltage on electrical property of films","volume":"8","author":"Ishibashi","year":"1990","journal-title":"J. Vac. Sci. Technol. A"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1007\/s13320-014-0165-4","article-title":"Crystalline Structure and Surface Morphology of Tin Oxide Films Grown by DC-Reactive Sputtering","volume":"4","author":"Khalaf","year":"2014","journal-title":"Photon. Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3797","DOI":"10.1063\/1.357383","article-title":"Optical and electrical properties of radio frequency sputtered tin oxide films doped with oxygen vacancies, F, Sb, or Mo","volume":"76","author":"Stjerna","year":"1994","journal-title":"J. Appl. Phys."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.tsf.2004.02.047","article-title":"Spectroscopic ellipsometry studies on the optical constants of indium tin oxide films deposited under various sputtering conditions","volume":"467","author":"Jung","year":"2004","journal-title":"Thin Solid Films"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1364\/OE.11.000430","article-title":"Analysis of one-dimensional photonic band gap structures with a liquid crystal defect towards development of fiber-optic tunable wavelength filters","volume":"11","author":"Matias","year":"2003","journal-title":"Opt. Express"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"438","DOI":"10.1364\/JOSA.67.000423","article-title":"Electromagnetic propagation in periodic stratified media. I. General theory","volume":"67","author":"Yeh","year":"1977","journal-title":"JOSA"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1016\/0039-6028(95)90028-4","article-title":"Water adsorption on stoichiometric and defective SnO2 (110) surfaces","volume":"322","author":"Gercher","year":"1995","journal-title":"Surf. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"720","DOI":"10.1016\/j.snb.2013.02.027","article-title":"Chemical Effect of composition on electrical response to humidity of TiO2: ZnO sensors investigated by impedance spectroscopy","volume":"181","author":"Faia","year":"2013","journal-title":"Sens. Actuators B Chem."},{"key":"ref_28","first-page":"8724","article-title":"Fabrication of Bragg gratings on the End Facet of Standard Optical Fibers by Sputtering the Same Material","volume":"35","author":"Ascorbe","year":"2016","journal-title":"J. Light. Technol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1063\/1.1904716","article-title":"Highly sensitive fiber Bragg grating refractive index sensors","volume":"86","author":"Liang","year":"2005","journal-title":"Appl. Phys. Lett."},{"key":"ref_30","first-page":"1","article-title":"Fibre Bragg Grating Sensors-An Introduction to Bragg gratings and interrogation techniques","volume":"1","author":"Doyle","year":"2003","journal-title":"Smart Fibres Ltd"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/5\/991\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:34:15Z","timestamp":1760207655000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/5\/991"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,4,29]]},"references-count":30,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2017,5]]}},"alternative-id":["s17050991"],"URL":"https:\/\/doi.org\/10.3390\/s17050991","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2017,4,29]]}}}