{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T19:26:03Z","timestamp":1778700363925,"version":"3.51.4"},"reference-count":31,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2020,1,29]],"date-time":"2020-01-29T00:00:00Z","timestamp":1580256000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Xiaoping Lou; Xinping Zhang","award":["61735002"],"award-info":[{"award-number":["61735002"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>An Ag-graphene layers-coated H-shaped photonic crystal fiber (PCF) surface plasmon resonance (SPR) sensor with a U-shaped grooves open structure for refractive index (RI) sensing is proposed and numerically simulated by the finite element method (FEM). The designed sensor could solve the problems of air-holes material coating and analyte filling in PCF. Two big air-holes in the x-axis produce a birefringence phenomenon leading to the confinement loss and sensitivity of x-polarized light being much stronger than y-polarized. Graphene is deposited on the layer of silver in the grooves; its high surface to volume ratio and rich \u03c0 conjugation make it a suitable dielectric layer for sensing. The effect of structure parameters such as air-holes size, U-shaped grooves depth, thickness of the silver layer and number of graphene layers on the sensing performance of the proposed sensor are numerical simulated. A large analyte RI range from 1.33 to 1.41 is calculated and the highest wavelength sensitivity is 12,600 nm\/RIU. In the linear RI sensing region of 1.33 to 1.36; the average wavelength sensitivity we obtained can reach 2770 nm\/RIU with a resolution of 3.61 \u00d7 10\u22125 RIU. This work provides a reference for developing a high-sensitivity; multi-parameter measurement sensor potentially useful for water pollution monitoring and biosensing in the future.<\/jats:p>","DOI":"10.3390\/s20030741","type":"journal-article","created":{"date-parts":[[2020,1,29]],"date-time":"2020-01-29T10:51:07Z","timestamp":1580295067000},"page":"741","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":121,"title":["A Refractive Index Sensor Based on H-Shaped Photonic Crystal Fibers Coated with Ag-Graphene Layers"],"prefix":"10.3390","volume":"20","author":[{"given":"Tianshu","family":"Li","sequence":"first","affiliation":[{"name":"School of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei 230009, China"}]},{"given":"Lianqing","family":"Zhu","sequence":"additional","affiliation":[{"name":"School of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei 230009, China"},{"name":"Beijing Laboratory of Optical Fiber Sensing and System, Beijing Information Science &amp; Technology University, Beijing 100016, China"}]},{"given":"Xianchao","family":"Yang","sequence":"additional","affiliation":[{"name":"Beijing Laboratory of Optical Fiber Sensing and System, Beijing Information Science &amp; Technology University, Beijing 100016, China"}]},{"given":"Xiaoping","family":"Lou","sequence":"additional","affiliation":[{"name":"Beijing Laboratory of Optical Fiber Sensing and System, Beijing Information Science &amp; Technology University, Beijing 100016, China"}]},{"given":"Liandong","family":"Yu","sequence":"additional","affiliation":[{"name":"School of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei 230009, China"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.snb.2016.04.020","article-title":"Chitosan\/PAA based fiber-optic interferometric sensor for heavy metal ions detection","volume":"233","author":"Raghunandhan","year":"2016","journal-title":"Sens. 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