{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T15:13:09Z","timestamp":1778685189469,"version":"3.51.4"},"reference-count":35,"publisher":"Optica Publishing Group","issue":"14","license":[{"start":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T00:00:00Z","timestamp":1777593600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/doi.org\/10.1364\/OA_License_v2#VOR"},{"start":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T00:00:00Z","timestamp":1777593600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/opg.optica.org\/policies\/opg-tdm-policy.json"}],"content-domain":{"domain":["opg.optica.org"],"crossmark-restriction":false},"short-container-title":["Appl. Opt."],"published-print":{"date-parts":[[2026,5,10]]},"abstract":"<jats:p>\n                    In this work, a compact optical waveguide grating sensor integrated\n\t\t\t\t\twith a gold (Au)\u2013zinc oxide (ZnO)-coated plus-shaped cavity (PSC) is\n\t\t\t\t\tproposed for ultra-sensitive refractive index (RI) sensing of\n\t\t\t\t\tcerebrospinal fluid (CSF).\n\t\t\t\t\tThe engineered PSC configuration significantly enhances light\u2013matter\n\t\t\t\t\tinteraction by enabling efficient phase-matched coupling of guided\n\t\t\t\t\tmodes to surface plasmon polaritons (SPPs) at the\n\t\t\t\t\tAu\u2013ZnO interface. The\n\t\t\t\t\tresulting strong electromagnetic field confinement is exploited\n\t\t\t\t\tfor precise RI-based\n\t\t\t\t\tinterrogation of CSF, whose RI varies from 1.33487 to 1.33924. For the\n\t\t\t\t\ttested RI range, the proposed sensor exhibits an auto-correlation\n\t\t\t\t\tcoefficient (\n\t    R\n                    <jats:sup>2<\/jats:sup>\n                    ) of 1 and a sensitivity of \n\t    3128.2(W.m\n                    <jats:sup>\u22121<\/jats:sup>\n                    )\u22c5RIU\n                    <jats:sup>\u22121<\/jats:sup>\n                    . This performance is achieved through\n\t\t\t\t\trigorous optimization of key excitation parameters, including the\n\t\t\t\t\tinput optical power, beam half-width, and operating wavelength.\n\t\t\t\t\tFurthermore, the influence of the PSC vertical slot width on device\n\t\t\t\t\tperformance is investigated to ensure robust and optimized sensing\n\t\t\t\t\tcharacteristics. The obtained results demonstrate that the proposed\n\t\t\t\t\tPSC-based SPR sensor offers a compact, highly reliable, and\n\t\t\t\t\thigh-resolution sensing platform, indicating potential for rapid and\n\t\t\t\t\taccurate RI-based diagnosis of CSF samples.\n                  <\/jats:p>","DOI":"10.1364\/ao.599798","type":"journal-article","created":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T12:00:09Z","timestamp":1776340809000},"page":"4654","update-policy":"https:\/\/doi.org\/10.1364\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Compact optical waveguide grating RI sensor integrated with an Au\u2013ZnO-coated plus-shaped cavity"],"prefix":"10.1364","volume":"65","author":[{"given":"Shreya","family":"Wadkar","sequence":"first","affiliation":[{"name":"Veermata Jijabai Technological Institute"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sandesh","family":"Khandagale","sequence":"additional","affiliation":[{"name":"Vivekanand Education Society\u2019s College of Arts, Science and Commerce"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anita","family":"Kanwar","sequence":"additional","affiliation":[{"name":"Vivekanand Education Society\u2019s College of Arts, Science and Commerce"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Niteshkumar","family":"Agrawal","sequence":"additional","affiliation":[{"name":"Veermata Jijabai Technological Institute"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3751-5975","authenticated-orcid":true,"given":"Lokendra","family":"Singh","sequence":"additional","affiliation":[{"name":"Graphic Era (Deemed to be University)"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"285","published-online":{"date-parts":[[2026,5,1]]},"reference":[{"key":"ao-65-14-4654-R1","doi-asserted-by":"publisher","first-page":"117470","DOI":"10.1016\/j.cca.2023.117470","type":"journal-article","volume":"548","author":"Yekani","year":"2023","journal-title":"Clin. 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All rights, including\n\t\t\t\t\tfor text and data mining (TDM), Artificial Intelligence (AI) training,\n\t\t\t\t\tand similar technologies, are reserved.","name":"copyright","label":"Copyright"}]}}