{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,18]],"date-time":"2026-01-18T09:40:24Z","timestamp":1768729224480,"version":"3.49.0"},"reference-count":12,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2010,5,11]],"date-time":"2010-05-11T00:00:00Z","timestamp":1273536000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A novel class of multi-D-shaped optical fiber suited for refractive index measurements is presented. The multi-D-shaped optical fiber was constructed by forming several D-sections in a multimode optical fiber at localized regions with femtosecond laser pulses. The total number of D-shaped zones fabricated could range from three to seven. Each D-shaped zone covered a sensor volume of 100 \u03bcm depth, 250 \u03bcm width, and 1 mm length. The mean roughness of the core surface obtained by the AFM images was 231.7 nm, which is relatively smooth. Results of the tensile test indicated that the fibers have sufficient mechanical strength to resist damage from further processing. The multi-D-shaped optical fiber as a high sensitive refractive-index sensor to detect changes in the surrounding refractive index was studied. The results for different concentrations of sucrose solution show that a resolution of 1.27 \u00d7 10\u22123\u20133.13 \u00d7 10\u22124 RIU is achieved for refractive indices in the range of 1.333 to 1.403, suggesting that the multi-D-shaped fibers are attractive for chemical, biological, and biochemical sensing with aqueous solutions.<\/jats:p>","DOI":"10.3390\/s100504794","type":"journal-article","created":{"date-parts":[[2010,5,11]],"date-time":"2010-05-11T11:15:10Z","timestamp":1273576510000},"page":"4794-4804","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":103,"title":["A Multi-D-Shaped Optical Fiber for Refractive Index Sensing"],"prefix":"10.3390","volume":"10","author":[{"given":"Chien-Hsing","family":"Chen","sequence":"first","affiliation":[{"name":"Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan"}]},{"given":"Tzu-Chein","family":"Tsao","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, National Chung Cheng University, Chia-Yi 621, Taiwan"}]},{"given":"Jaw-Luen","family":"Tang","sequence":"additional","affiliation":[{"name":"Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan"}]},{"given":"Wei-Te","family":"Wu","sequence":"additional","affiliation":[{"name":"Department of Biomechatronics Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan"}]}],"member":"1968","published-online":{"date-parts":[[2010,5,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1021\/ac020310v","article-title":"Colloidal gold-modified optical fiber for chemical and biochemical sensing","volume":"75","author":"Cheng","year":"2003","journal-title":"Anal. 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Laser-Induced Long-Period Fiber Grating Sensor Modified with Gold Nano-Rods, CLEO-PR.","DOI":"10.1109\/CLEOPR.2009.5292397"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"171","DOI":"10.3390\/s8010171","article-title":"Chemical sensing sensitivity of long-period grating sensor enhanced by colloidal gold nanoparticles","volume":"8","author":"Tang","year":"2008","journal-title":"Sensors"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/10\/5\/4794\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T22:02:24Z","timestamp":1760220144000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/10\/5\/4794"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2010,5,11]]},"references-count":12,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2010,5]]}},"alternative-id":["s100504794"],"URL":"https:\/\/doi.org\/10.3390\/s100504794","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2010,5,11]]}}}