{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T03:34:37Z","timestamp":1783481677232,"version":"3.55.0"},"reference-count":29,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2021,11,30]],"date-time":"2021-11-30T00:00:00Z","timestamp":1638230400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Natural National Science Foundation of China (NSFC)","award":["61905105"],"award-info":[{"award-number":["61905105"]}]},{"name":"Guangdong science and technology innovation strategy project","award":["2018A01006"],"award-info":[{"award-number":["2018A01006"]}]},{"name":"Science and Technology Program of Guangdong Province","award":["2020A0505100059"],"award-info":[{"award-number":["2020A0505100059"]}]},{"DOI":"10.13039\/501100003453","name":"Natural Science Foundation of Guangdong Province","doi-asserted-by":"publisher","award":["2020A1515011451, 2021A1515011928"],"award-info":[{"award-number":["2020A1515011451, 2021A1515011928"]}],"id":[{"id":"10.13039\/501100003453","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Major projects of basic and application research in Guangdong Province","award":["2018KQNCX151, 2020KTSCX073"],"award-info":[{"award-number":["2018KQNCX151, 2020KTSCX073"]}]},{"name":"Special talents project of Lingnan Normal University] grant number","award":["ZL1617, ZL2046, ZL1931"],"award-info":[{"award-number":["ZL1617, ZL2046, ZL1931"]}]},{"name":"Zhanjiang science and technology plan project] grant number","award":["2016B01041, 2018A02010, 2019A01044, 2019B01001"],"award-info":[{"award-number":["2016B01041, 2018A02010, 2019A01044, 2019B01001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We proposed a differential fiber-optic refractive index sensor based on coupled plasmon waveguide resonance (CPWR) in the C-band. The sensor head is a BK7 prism coated with ITO\/Au\/ITO\/TiO2 film. CPWR is excited on the film by the S-polarized components of an incident light. The narrow absorption peak of CPWR makes it possible to realize dual-wavelength differential intensity (DI) interrogation by using only one incident point. To implement DI interrogation, we used a DWDM component to sample the lights with central wavelengths of 1529.55 and 1561.42 nm from the lights reflected back by the sensor head. The intensities of the dual-wavelength lights varied oppositely within the measurement range of refractive index, thus, a steep slope was produced as the refractive index of the sample increased. The experimental results show that the sensitivity is 32.15\/RIUs within the measurement range from 1.3584 to 1.3689 and the resolution reaches 9.3 \u00d7 10\u22126 RIUs. Benefiting from the single incident point scheme, the proposed sensor would be easier to calibrate in bio-chemical sensing applications. Moreover, this sensing method is expected to be applied to retro-reflecting SPR sensors with tapered fiber tip to achieve better resolution than wavelength interrogation.<\/jats:p>","DOI":"10.3390\/s21237984","type":"journal-article","created":{"date-parts":[[2021,12,1]],"date-time":"2021-12-01T01:45:02Z","timestamp":1638323102000},"page":"7984","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Differential Refractive Index Sensor Based on Coupled Plasmon Waveguide Resonance in the C-Band"],"prefix":"10.3390","volume":"21","author":[{"given":"Qian","family":"Yang","sequence":"first","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laixu","family":"Gao","sequence":"additional","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Changwei","family":"Zou","sequence":"additional","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Xie","sequence":"additional","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Canxin","family":"Tian","sequence":"additional","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zesong","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Feng","family":"Liang","sequence":"additional","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yihong","family":"Ke","sequence":"additional","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinmei","family":"Zhou","sequence":"additional","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Songquan","family":"Li","sequence":"additional","affiliation":[{"name":"College of Physical Science & Technology, Lingnan Normal University, Zhanjiang 524048, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Duan, Q.L., Liu, Y.N., Chang, S.S., Chen, H.Y., and Chen, J.H. (2021). Surface Plasmonic Sensors: Sensing Mechanism and Recent Applications. Sensors, 21.","DOI":"10.3390\/s21165262"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Dos Santos Paulo, S.S., De Almeida Jose, M.M., Pastoriza-Santos, I., and Coelho Luis, C.C. (2021). Advances in Plasmonic Sensing at the NIR\u2014A Review. Sensors, 21.","DOI":"10.3390\/s21062111"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1699","DOI":"10.1364\/PRJ.431612","article-title":"Lasing-enhanced surface plasmon resonance spectroscopy and sensing","volume":"9","author":"Zhang","year":"2021","journal-title":"Photonics Res."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Klantsataya, E., Jia, P., Ebendorff-Heidepriem, H., Monro, T.M., and Fran\u00e7ois, A. (2017). Plasmonic Fiber Optic Refractometric Sensors: From Conventional Architectures to Recent Design Trends. Sensors, 17.","DOI":"10.3390\/s17010012"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1801433","DOI":"10.1002\/adom.201801433","article-title":"Optical Refractive Index Sensors with Plasmonic and Photonic Structures: Promising and Inconvenient Truth","volume":"7","author":"Xu","year":"2019","journal-title":"Adv. Opt. Mater."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"21841","DOI":"10.1364\/OE.25.021841","article-title":"Segmented detection SPR sensor based on seven-core fiber","volume":"25","author":"Wei","year":"2017","journal-title":"Opt. Express"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2826","DOI":"10.1364\/OL.40.002826","article-title":"Twin-core fiber SPR sensor","volume":"40","author":"Liu","year":"2015","journal-title":"Opt. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1016\/S0925-4005(97)00290-6","article-title":"A surface plasmon resonance sensor probe based on retro-reflection","volume":"45","author":"Cahill","year":"1997","journal-title":"Sens. Actuators B"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/S0925-4005(00)00690-0","article-title":"A surface plasmon resonance side active retro-reflecting sensor","volume":"73","author":"Jorgenson","year":"2001","journal-title":"Sens. Actuators B"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1016\/j.snb.2017.02.064","article-title":"A compact, flexible fiber-optic Surface Plasmon Resonance sensor with changeable sensor chips","volume":"246","author":"Michel","year":"2017","journal-title":"Sens. Actuators B"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"33809","DOI":"10.1364\/OE.387413","article-title":"Highly sensitive differential fiber-optic SPR sensor in telecom band","volume":"28","author":"Li","year":"2020","journal-title":"Opt. Express"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2000763","DOI":"10.1002\/advs.202000763","article-title":"Label-free near-infrared plasmonic sensing technique for DNA detection at ultralow concentrations","volume":"7","author":"Chen","year":"2020","journal-title":"Adv. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"9754083","DOI":"10.34133\/2021\/9754083","article-title":"Fano-Resonant Hybrid Metamaterial for Enhanced Nonlinear Tunability and Hysteresis Behavior","volume":"2021","author":"Fan","year":"2021","journal-title":"Research"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"091106","DOI":"10.1063\/1.4990766","article-title":"High-quality metamaterial dispersive grating on the facet of an optical fiber","volume":"111","author":"Savinov","year":"2017","journal-title":"Appl. Phys. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1800502","DOI":"10.1002\/adom.201800502","article-title":"Shaping high-Q planar Fano resonant metamaterials towards futuristic technologies","volume":"6","author":"Lim","year":"2018","journal-title":"Adv. Opt. Mater."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1016\/j.bios.2004.03.014","article-title":"A sensitivity comparison of optical biosensors based on four different surface plasmon resonance modes","volume":"20","author":"Chien","year":"2004","journal-title":"Biosens. Bioelectron."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.optlaseng.2018.09.013","article-title":"Long-range surface plasmon resonance and its sensing applications: A review","volume":"112","author":"Jing","year":"2019","journal-title":"Opt. Lasers Eng."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"065101","DOI":"10.1088\/1361-6463\/aaf0f7","article-title":"Two-dimensional transition metal dichalcogenides mediated long range surface plasmon resonance biosensors","volume":"52","author":"Xu","year":"2019","journal-title":"J. Phys. D Appl. Phys."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/j.snb.2008.08.029","article-title":"Long-range surface plasmons for sensitive detection of bacterial analytes","volume":"139","author":"Vala","year":"2009","journal-title":"Sens. Actuators B"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"353","DOI":"10.1002\/sca.4950160606","article-title":"Surface Plasmon and Guided Optical Wave Microscopies","volume":"16","author":"Aust","year":"1994","journal-title":"Scanning"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"104308","DOI":"10.1016\/j.rinp.2021.104308","article-title":"High-performance coupled plasmon waveguide resonance optical sensor based on SiO2:Ag film","volume":"26","author":"Jiang","year":"2021","journal-title":"Results Phys."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1465","DOI":"10.1016\/j.bios.2003.12.001","article-title":"A novel ultrahigh-resolution surface plasmon resonance biosensor with an Au nanocluster-embedded dielectric film","volume":"19","author":"Hu","year":"2004","journal-title":"Biosens. Bioelectron."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"11280","DOI":"10.1364\/OE.389279","article-title":"All optic-fiber coupled plasmon waveguide resonance sensor using ZrS2 based dielectric layer","volume":"28","author":"Ma","year":"2020","journal-title":"Opt. Express"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"552","DOI":"10.1016\/j.optcom.2017.10.072","article-title":"Theoretical modeling of a coupled plasmon waveguide resonance sensor based on multimode optical fiber","volume":"410","author":"Liu","year":"2018","journal-title":"Opt. Commun."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"5056","DOI":"10.1103\/PhysRevB.9.5056","article-title":"Optical constants of transition metals: Ti, V, Cr, Mn, Fe, Co, Ni, and Pd","volume":"9","author":"Johnson","year":"1974","journal-title":"Phys. Rev. B"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1007\/s11468-016-0301-7","article-title":"Highly sensitive SPR sensor based on D-shaped photonic crystal fiber coated with indium tin oxide at near-infrared wavelength","volume":"12","author":"Huang","year":"2017","journal-title":"Plasmonics"},{"key":"ref_27","first-page":"011071","article-title":"Nonmodal plasmonics: Controlling the forced optical response of nanostructures","volume":"10","author":"Rosenblatt","year":"2020","journal-title":"Phys. Rev. X"},{"key":"ref_28","unstructured":"(2021, October 02). Refractive.INFO. Available online: https:\/\/refractiveindex.info\/?shelf=main&book=TiO2&page=Sarkar."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Hjelme, D.R. (2017, January 24\u201327). A lower bound on the resolution limit of resonant refractive index sensors. Proceedings of the Advanced Photonics 2017 (IPR, NOMA, Sensors, Networks, SPPCom, PS), New Orleans, LA, USA.","DOI":"10.1364\/SENSORS.2017.SeM2E.2"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/23\/7984\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:37:41Z","timestamp":1760168261000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/23\/7984"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,11,30]]},"references-count":29,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2021,12]]}},"alternative-id":["s21237984"],"URL":"https:\/\/doi.org\/10.3390\/s21237984","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,11,30]]}}}