{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T13:28:17Z","timestamp":1780493297435,"version":"3.54.1"},"reference-count":30,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2018,4,26]],"date-time":"2018-04-26T00:00:00Z","timestamp":1524700800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Science and Technology Planning Projects of Guangdong Province, China","award":["2016A020223013"],"award-info":[{"award-number":["2016A020223013"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61405039, 61475037"],"award-info":[{"award-number":["61405039, 61475037"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Natural Science Foundation of Guangdong Province, China","award":["2014A030310300"],"award-info":[{"award-number":["2014A030310300"]}]},{"name":"the State Key Lab of Optical Technologies for Micro-Engineering and Nano-Fabrication of China"},{"name":"the Foundation for Distinguished Young Talents in Higher Education of Guangdong, China","award":["2014KQNCX066"],"award-info":[{"award-number":["2014KQNCX066"]}]},{"name":"the Research Fund of Guangdong University of Technology","award":["16ZK0041,  13ZK0387"],"award-info":[{"award-number":["16ZK0041,  13ZK0387"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper, a multichannel refractive index sensor based on a subwavelength metal\u2013insulator\u2013metal (MIM) waveguide coupled with tangent-ring resonators is proposed. When two tangent-ring resonators were placed above the MIM waveguide, Fano resonance with asymmetrical line shape appeared in the transmission spectrum due to the interference between the light\u2013dark resonant modes. The sensitivity and figure of merit were as high as 880 nm\/RIU and 964, respectively. Through adding more tangent-ring resonators, multiple Fano resonances with ultrasharp peaks\/dips were achieved in the wavelength range of 800\u20132000 nm. Besides, negative group delays were also observed in the Fano resonant dips. Two-dimensional finite-difference time-domain (FDTD) method was used to simulate and analyze the performances of the proposed structures. These kinds of multiring structures can find important applications in the on-chip optical sensing and optical communication areas.<\/jats:p>","DOI":"10.3390\/s18051348","type":"journal-article","created":{"date-parts":[[2018,4,27]],"date-time":"2018-04-27T06:52:23Z","timestamp":1524811943000},"page":"1348","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":81,"title":["Plasmonic Multichannel Refractive Index Sensor Based on Subwavelength Tangent-Ring Metal\u2013Insulator\u2013Metal Waveguide"],"prefix":"10.3390","volume":"18","author":[{"given":"Zicong","family":"Guo","sequence":"first","affiliation":[{"name":"School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kunhua","family":"Wen","sequence":"additional","affiliation":[{"name":"School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qinyang","family":"Hu","sequence":"additional","affiliation":[{"name":"School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenhui","family":"Lai","sequence":"additional","affiliation":[{"name":"School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiyan","family":"Lin","sequence":"additional","affiliation":[{"name":"School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yihong","family":"Fang","sequence":"additional","affiliation":[{"name":"School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,4,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"641","DOI":"10.1038\/nphoton.2007.223","article-title":"Nano-optics from sensing to waveguiding","volume":"1","author":"Lal","year":"2007","journal-title":"Nat. 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