An Extrinsic Fiber-Optic Gas Sensor Employing Distributed Bragg Reflectors

An Extrinsic Fiber-Optic Gas Sensor Employing Distributed Bragg Reflectors | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article An Extrinsic Fiber-Optic Gas Sensor Employing Distributed Bragg Reflectors Michal Gryga, Jakub Chylek, Roman Kanok, Dalibor Ciprian, Petr Hlubina This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9159829/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract A new concept of an extrinsic fiber-optic gas sensor employing a cavity with distributed Bragg reflectors (DBRs) is proposed and experimentally demonstrated using the wavelength interrogation. The DBR is represented by a one-dimensional photonic crystal (1DPhC) comprising six bilayers of TiO 2 /SiO 2 with a termination layer of TiO 2 , and the cavity of the adjustable thickness is realized by means of springs separating two parts of the fiber connector adapter to which the DBRs are glued. Two different extrinsic fiber-optic gas sensors are experimentally analyzed with results manifesting different technologies with which the DBRs are manufactured. The transmission spectra of the fiber-optic sensors are measured in visible and near-infrared spectral regions for a humid air, and we revealed, in accordance with the theory, narrow peaks within the 1DPhC band gap due to the cavity modes. The first sensor employs porous DBRs and has a maximum sensitivity at low relative humidities (RHs) of air, and the sensitivity to the RH of air, figure of merit (FOM) and the limit of detection (LOD) reached at 25 %RH values of 0.566 nm/%RH, 0.094 %RH -1 and 0.018 %RH, respectively. The second sensor is characterized by the sensitivity increasing with the RH, and the sensitivity and FOM attained at 70 %RH values of 0.109 nm/%RH and 0.017 %RH -1 , respectively. An extrinsic fiber-optic gas sensor employing a cavity with DBRs of adjustable thickness has the potential to be used in a great number of gas sensing applications. Photonics/optics extrinsic fiber-optic sensor distributed Bragg reflectors (DBRs) cavity gas sensor wavelength interrogation relative humidity sensitivity Full Text Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9159829","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":608292613,"identity":"9f7c1a37-9fbc-4ea2-bf27-592894d37ccd","order_by":0,"name":"Michal Gryga","email":"","orcid":"https://orcid.org/0000-0002-5394-7164","institution":"Department of Physics, Technical University Ostrava","correspondingAuthor":false,"prefix":"","firstName":"Michal","middleName":"","lastName":"Gryga","suffix":""},{"id":608292614,"identity":"3773d580-dca5-4f9b-a948-fcf125adf070","order_by":1,"name":"Jakub 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Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"extrinsic fiber-optic sensor, distributed Bragg reflectors (DBRs), cavity, gas sensor, wavelength interrogation, relative humidity, sensitivity","lastPublishedDoi":"10.21203/rs.3.rs-9159829/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9159829/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eA new concept of an extrinsic fiber-optic gas sensor employing a cavity with distributed Bragg reflectors (DBRs) is proposed and experimentally demonstrated using the wavelength interrogation. The DBR is represented by a one-dimensional photonic crystal (1DPhC) comprising six bilayers of TiO\u003csup\u003e\u003csub\u003e2\u003c/sub\u003e\u003c/sup\u003e/SiO\u003csub\u003e2\u003c/sub\u003e with a termination layer of TiO\u003csub\u003e2\u003c/sub\u003e, and the cavity of the adjustable thickness is realized by means of springs separating two parts of the fiber connector adapter to which the DBRs are glued. Two different extrinsic fiber-optic gas sensors are experimentally analyzed with results manifesting different technologies with which the DBRs are manufactured. The transmission spectra of the fiber-optic sensors are measured in visible and near-infrared spectral regions for a humid air, and we revealed, in accordance with the theory, narrow peaks within the 1DPhC band gap due to the cavity modes. The first sensor employs porous DBRs and has a maximum sensitivity at low relative humidities (RHs) of air, and the sensitivity to the RH of air, figure of merit (FOM) and the limit of detection (LOD) reached at 25 %RH values of 0.566 nm/%RH, 0.094 %RH\u003csup\u003e-1\u003c/sup\u003e and 0.018 %RH, respectively. The second sensor is characterized by the sensitivity increasing with the RH, and the sensitivity and FOM attained at 70 %RH values of 0.109 nm/%RH and 0.017 %RH\u003csup\u003e-1\u003c/sup\u003e, respectively. An extrinsic fiber-optic gas sensor employing a cavity with DBRs of adjustable thickness has the potential to be used in a great number of gas sensing applications.\u003c/p\u003e","manuscriptTitle":"An Extrinsic Fiber-Optic Gas Sensor Employing Distributed Bragg Reflectors","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-19 07:50:01","doi":"10.21203/rs.3.rs-9159829/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5b131ac1-46f1-474d-a48d-172600328b89","owner":[],"postedDate":"March 19th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":64729849,"name":"Photonics/optics"}],"tags":[],"updatedAt":"2026-03-19T07:50:01+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-19 07:50:01","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9159829","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9159829","identity":"rs-9159829","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}