{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T03:33:37Z","timestamp":1775705617966,"version":"3.50.1"},"reference-count":22,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2024,6,7]],"date-time":"2024-06-07T00:00:00Z","timestamp":1717718400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union\u2019s Horizon 2020 research and innovation programs","award":["101007448 (ICT GRACED)"],"award-info":[{"award-number":["101007448 (ICT GRACED)"]}]},{"name":"European Union\u2019s Horizon 2020 research and innovation programs","award":["101093166 (AMBROSIA)"],"award-info":[{"award-number":["101093166 (AMBROSIA)"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper, we study both theoretically and experimentally the sensitivity of bimodal interferometric sensors where interference occurs between two plasmonic modes with different properties propagating in the same physical waveguide. In contrast to the well-known Mach\u2013Zehnder interferometric (MZI) sensor, we show for the first time that the sensitivity of the bimodal sensor is independent of the sensing area length. This is validated by applying the theory to an integrated plasmo-photonic bimodal sensor that comprises an aluminum (Al) plasmonic stripe waveguide co-integrated between two accessible SU-8 photonic waveguides. A series of such bimodal sensors utilizing plasmonic stripes of different lengths were numerically simulated, demonstrating bulk refractive index (RI) sensitivities around 5700 nm\/RIU for all sensor variants, confirming the theoretical results. The theoretical and numerical results were also validated experimentally through chip-level RI sensing experiments on three fabricated SU-8\/Al bimodal sensors with plasmonic sensing lengths of 50, 75, and 100 \u03bcm. The obtained experimental RI sensitivities were found to be very close and equal to 4464, 4386, and 4362 nm\/RIU, respectively, confirming that the sensing length has no effect on the bimodal sensor sensitivity. The above outcome alleviates the design and optical loss constraints, paving the way for more compact and powerful sensors that can achieve high sensitivity values at ultra-short sensing lengths.<\/jats:p>","DOI":"10.3390\/s24123705","type":"journal-article","created":{"date-parts":[[2024,6,7]],"date-time":"2024-06-07T08:05:17Z","timestamp":1717747517000},"page":"3705","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Theoretical and Experimental Analysis of Single-Arm Bimodal Plasmo-Photonic Refractive Index Sensors"],"prefix":"10.3390","volume":"24","author":[{"given":"Konstantinos","family":"Fotiadis","sequence":"first","affiliation":[{"name":"Department of Informatics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"},{"name":"Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Balkan Center, Buildings A & B, 10th km Thessaloniki-Thermi Rd, 57001 Thessaloniki, Greece"}]},{"given":"Evangelia","family":"Chatzianagnostou","sequence":"additional","affiliation":[{"name":"Department of Informatics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"},{"name":"Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Balkan Center, Buildings A & B, 10th km Thessaloniki-Thermi Rd, 57001 Thessaloniki, Greece"}]},{"given":"Dimosthenis","family":"Spasopoulos","sequence":"additional","affiliation":[{"name":"Department of Informatics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"},{"name":"Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Balkan Center, Buildings A & B, 10th km Thessaloniki-Thermi Rd, 57001 Thessaloniki, Greece"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0776-3532","authenticated-orcid":false,"given":"Stelios","family":"Simos","sequence":"additional","affiliation":[{"name":"Department of Informatics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"},{"name":"Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Balkan Center, Buildings A & B, 10th km Thessaloniki-Thermi Rd, 57001 Thessaloniki, Greece"}]},{"given":"Dimitris V.","family":"Bellas","sequence":"additional","affiliation":[{"name":"Department of Informatics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"},{"name":"Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Balkan Center, Buildings A & B, 10th km Thessaloniki-Thermi Rd, 57001 Thessaloniki, Greece"},{"name":"Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina, Greece"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9738-3121","authenticated-orcid":false,"given":"Omkar","family":"Bhalerao","sequence":"additional","affiliation":[{"name":"AMO GmbH, Advanced Microelectronic Center Aachen, 52074 Aachen, Germany"},{"name":"Electronic Devices, RWTH Aachen University, 52074 Aachen, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1116-169X","authenticated-orcid":false,"given":"Stephan","family":"Suckow","sequence":"additional","affiliation":[{"name":"AMO GmbH, Advanced Microelectronic Center Aachen, 52074 Aachen, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4552-2411","authenticated-orcid":false,"given":"Max C.","family":"Lemme","sequence":"additional","affiliation":[{"name":"AMO GmbH, Advanced Microelectronic Center Aachen, 52074 Aachen, Germany"},{"name":"Electronic Devices, RWTH Aachen University, 52074 Aachen, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9552-9366","authenticated-orcid":false,"given":"Elefterios","family":"Lidorikis","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina, Greece"}]},{"given":"Nikos","family":"Pleros","sequence":"additional","affiliation":[{"name":"Department of Informatics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece"},{"name":"Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Balkan Center, Buildings A & B, 10th km Thessaloniki-Thermi Rd, 57001 Thessaloniki, Greece"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1016\/j.snb.2013.07.053","article-title":"Highly sensitive Mach-Zehnder interferometer biosensor based on silicon nitride slot waveguide","volume":"188","author":"Liu","year":"2013","journal-title":"Sens. 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