{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,26]],"date-time":"2026-06-26T22:22:58Z","timestamp":1782512578739,"version":"3.54.5"},"reference-count":49,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2017,8,11]],"date-time":"2017-08-11T00:00:00Z","timestamp":1502409600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000001","name":"US NSF","doi-asserted-by":"publisher","award":["ECCS-1407947"],"award-info":[{"award-number":["ECCS-1407947"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"name":"US ARO","award":["W911NF-15-1-0431"],"award-info":[{"award-number":["W911NF-15-1-0431"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>High sensitivity (S) and high quality factor (Q) are desirable to achieve low detection limit in label-free optical sensors. In this paper, we theoretically demonstrate that single-layer and coupled bi-layer photonic crystal slabs (PCS) possess simultaneously high S and high Q near the bound states in the continuum (BIC). We theoretically achieved S &gt; 800 nm\/RIU and Q &gt; 107 in refractive index sensing in the 1400\u20131600 nm telecom optical wavelength bands. We experimentally demonstrated an S of 94 nm\/RIU and a Q of 1.2 \u00d7 104, with a detection limit of 6 \u00d7 10\u22125 refractive index unit. These sensor designs can find applications in biochemical sensing, environmental monitoring, and healthcare.<\/jats:p>","DOI":"10.3390\/s17081861","type":"journal-article","created":{"date-parts":[[2017,8,11]],"date-time":"2017-08-11T10:07:40Z","timestamp":1502446060000},"page":"1861","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":138,"title":["Optical Refractive Index Sensing Based on High-Q Bound States in the Continuum in Free-Space Coupled Photonic Crystal Slabs"],"prefix":"10.3390","volume":"17","author":[{"given":"Yonghao","family":"Liu","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, University of Texas at Arlington, Arlington, TX 76019, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weidong","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, University of Texas at Arlington, Arlington, TX 76019, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5149-2277","authenticated-orcid":false,"given":"Yuze","family":"Sun","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, University of Texas at Arlington, Arlington, TX 76019, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,8,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.aca.2008.05.022","article-title":"Sensitive optical biosensors for unlabeled targets: A review","volume":"620","author":"Fan","year":"2008","journal-title":"Anal. 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