{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T09:06:32Z","timestamp":1777453592633,"version":"3.51.4"},"reference-count":28,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2019,9,27]],"date-time":"2019-09-27T00:00:00Z","timestamp":1569542400000},"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 the present paper, a new kind of concave shaped refractive index sensor (CSRIS) exploiting localized surface plasmon resonance (LSPR) is proposed and numerically optimized. The LSPR effect between polaritons and the core guided mode of designed CSRIS is used to enhance the sensing performance. The sensor is characterized for two types of sensing structures coated with gold (Au) film and Au nanowires (AuNWs), respectively. The influence of structural parameters such as the distance (D) of the concave shaped channel (CSC) from the core, the diameter of the nanowire (dn) and the size (s) of the CSC are investigated here. In comparison to Au film, the AuNWs are shown to significantly enhance the sensitivity and the performance of the designed sensor. An enhanced sensitivity of 4471 nm\/RIU (refractive index unit) is obtained with AuNWs, for a wide range of analytes refractive index (na) varying between 1.33 to 1.38. However, for conventional Au film; the sensitivity of 808.57 nm\/RIU is obtained for the same range of analytes.<\/jats:p>","DOI":"10.3390\/s19194210","type":"journal-article","created":{"date-parts":[[2019,9,27]],"date-time":"2019-09-27T11:14:35Z","timestamp":1569582875000},"page":"4210","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":60,"title":["Sensitivity Enhancement of a Concave Shaped Optical Fiber Refractive Index Sensor Covered with Multiple Au Nanowires"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1656-3428","authenticated-orcid":false,"given":"A. K.","family":"Pathak","sequence":"first","affiliation":[{"name":"Optical Fiber Laboratory, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India"},{"name":"Department of School of Mathematics, Computer Science and Engineering, City University London, London EC1V 0HB, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"B. M. A.","family":"Rahman","sequence":"additional","affiliation":[{"name":"Department of School of Mathematics, Computer Science and Engineering, City University London, London EC1V 0HB, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"V. K.","family":"Singh","sequence":"additional","affiliation":[{"name":"Optical Fiber Laboratory, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S.","family":"Kumari","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Indian Institute of Technology, Patna 801106, India"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,9,27]]},"reference":[{"key":"ref_1","first-page":"2135","article-title":"Notizen: Radiative decay of non radiative surface plasmons excited by light","volume":"23","author":"Kretschmann","year":"1986","journal-title":"Z. Nat. A"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/S0925-4005(98)00321-9","article-title":"Surface plasmon resonance sensors: Review","volume":"54","author":"Homola","year":"1999","journal-title":"Sens. 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