{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T05:07:39Z","timestamp":1772600859959,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2023,4,13]],"date-time":"2023-04-13T00:00:00Z","timestamp":1681344000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Sentinel North program of the Canada First Research Excellence Fund"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Evanescent field excitation is a powerful means to achieve a high surface-to-bulk signal ratio for bioimaging and sensing applications. However, standard evanescent wave techniques such as TIRF and SNOM require complex microscopy setups. Additionally, the precise positioning of the source relative to the analytes of interest is required, as the evanescent wave is critically distance-dependent. In this work, we present a detailed investigation of evanescent field excitation of near-surface waveguides written using femtosecond laser in glass. We studied the waveguide-to-surface distance and refractive index change to attain a high coupling efficiency between evanescent waves and organic fluorophores. First, our study demonstrated a reduction in sensing efficiency for waveguides written at their minimum distance to the surface without ablation as the refractive index contrast of the waveguide increased. While this result was anticipated, it had not been previously demonstrated in the literature. Moreover, we found that fluorescence excitation by waveguides can be enhanced using plasmonic silver nanoparticles. The nanoparticles were also organized in linear assemblies, perpendicular to the waveguide, with a wrinkled PDMS stamp technique, which resulted in an excitation enhancement of over 20 times compared to the setup without nanoparticles.<\/jats:p>","DOI":"10.3390\/s23083945","type":"journal-article","created":{"date-parts":[[2023,4,13]],"date-time":"2023-04-13T04:33:26Z","timestamp":1681360406000},"page":"3945","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Enhancing Evanescent Wave Coupling of Near-Surface Waveguides with Plasmonic Nanoparticles"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3155-1871","authenticated-orcid":false,"given":"Jerome","family":"Lapointe","sequence":"first","affiliation":[{"name":"Centre d\u2019Optique, Photonique et Laser, Universit\u00e9 Laval, 2375 Rue de la Terrasse, Qu\u00e9bec, QC G1V 0A6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexandre","family":"Gr\u00e9goire","sequence":"additional","affiliation":[{"name":"Centre d\u2019Optique, Photonique et Laser, Universit\u00e9 Laval, 2375 Rue de la Terrasse, Qu\u00e9bec, QC G1V 0A6, Canada"},{"name":"D\u00e9partement de Chimie, Universit\u00e9 Laval, 2375 Rue de la Terrasse, Qu\u00e9bec, QC G1V 0A6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jean-Philippe","family":"B\u00e9rub\u00e9","sequence":"additional","affiliation":[{"name":"Ciena Corporation, 505 Boulevard du Parc Technologique, Suite 100, Qu\u00e9bec, QC G1P 4S9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R\u00e9al","family":"Vall\u00e9e","sequence":"additional","affiliation":[{"name":"Centre d\u2019Optique, Photonique et Laser, Universit\u00e9 Laval, 2375 Rue de la Terrasse, Qu\u00e9bec, QC G1V 0A6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"21662","DOI":"10.1364\/OE.16.021662","article-title":"High-Contrast Waveguides in Sputtered Pure TeO2 Glass Thin Films","volume":"16","author":"Pietralunga","year":"2008","journal-title":"Opt. 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