{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,14]],"date-time":"2026-06-14T21:47:17Z","timestamp":1781473637540,"version":"3.54.1"},"reference-count":40,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2016,9,15]],"date-time":"2016-09-15T00:00:00Z","timestamp":1473897600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A D-shaped polarization-maintaining fiber (PMF) as fiber optic sensor for the simultaneous monitoring of strain and the surrounding temperature is presented. A mechanical end and edge polishing system with aluminum oxide polishing film is utilized to perform sequential polishing on one side (lengthwise) of the PMF in order to fabricate a D-shaped cross-section. Experimental results show that the proposed sensor has high sensitivity of 46 pm\/\u00b5\u03b5 and 130 pm\/\u00b0C for strain and temperature, respectively, which is significantly higher than other recently reported work (mainly from 2013) related to fiber optic sensors. The easy fabrication method, high sensitivity, and good linearity make this sensing device applicable in various applications such as health monitoring and spatial analysis of engineering structures.<\/jats:p>","DOI":"10.3390\/s16091505","type":"journal-article","created":{"date-parts":[[2016,9,15]],"date-time":"2016-09-15T10:22:51Z","timestamp":1473934971000},"page":"1505","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":33,"title":["D-Shaped Polarization Maintaining Fiber Sensor for Strain and Temperature Monitoring"],"prefix":"10.3390","volume":"16","author":[{"given":"Hummad","family":"Qazi","sequence":"first","affiliation":[{"name":"Faculty of Electrical Engineering, Universiti Teknologi Malaysia, UTM, Skudai, 81310 Johor, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abu","family":"Mohammad","sequence":"additional","affiliation":[{"name":"Faculty of Electrical Engineering, Universiti Teknologi Malaysia, UTM, Skudai, 81310 Johor, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Harith","family":"Ahmad","sequence":"additional","affiliation":[{"name":"Photonics Research Centre, University of Malaya, 50603 Kuala Lumpur, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohd","family":"Zulkifli","sequence":"additional","affiliation":[{"name":"Photonics Research Centre, University of Malaya, 50603 Kuala Lumpur, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2016,9,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"9996","DOI":"10.1364\/OE.21.009996","article-title":"Highly sensitive in-fiber interferometric refractometer with temperature and axial strain compensation","volume":"21","author":"Harris","year":"2013","journal-title":"Opt. Express"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"717","DOI":"10.1016\/j.snb.2012.11.095","article-title":"Simultaneous measurement of refractive index and temperature using multimode interference inside a high birefringence fiber loop mirror","volume":"177","author":"Gouveia","year":"2013","journal-title":"Sens. Actuators B Chem."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1016\/j.optcom.2014.02.035","article-title":"A fiber strain and vibration sensor based on high birefringence polarization maintaining fibers","volume":"322","author":"Kang","year":"2014","journal-title":"Opt. Commun."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"067101","DOI":"10.1117\/1.OE.53.6.067101","article-title":"Simultaneous measurement of temperature and pressure with cascaded extrinsic Fabry-Perot interferometer and intrinsic Fabry-Perot interferometer sensors","volume":"53","author":"Zhang","year":"2014","journal-title":"Opt. Eng."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2970","DOI":"10.3390\/s7112970","article-title":"Recent advances in high-birefringence fiber loop mirror sensors","volume":"7","author":"Baptista","year":"2007","journal-title":"Sensors"},{"key":"ref_6","unstructured":"Froggatt, M.E., Gifford, D.K., Kreger, S.T., Wolfe, M.S., and Soller, B.J. (2006). Optical Fiber Sensors, Optical Society of America."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1120","DOI":"10.1109\/LPT.2010.2050474","article-title":"Fiber loop mirror using a small core microstructured fiber for strain and temperature discrimination","volume":"22","author":"Andre","year":"2010","journal-title":"IEEE Photon. Technol. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3589","DOI":"10.1364\/OE.23.003589","article-title":"Simultaneous multi-parameter measurement using Sagnac loop hybrid interferometer based on a highly birefringent photonic crystal fiber with two asymmetric cores","volume":"23","author":"Naeem","year":"2015","journal-title":"Opt. Express"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"55205","DOI":"10.1088\/0957-0233\/25\/5\/055205","article-title":"A simultaneous strain and temperature sensing module based on FBG-in-SMS","volume":"25","author":"Song","year":"2014","journal-title":"Meas. Sci. Technol."},{"key":"ref_10","unstructured":"Wolfbeis, O.S. (1991). Fiber Optic Chemical Sensors and Biosensors, CRC Press."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Yin, S.S., and Ruffin, P. (2002). Fiber Optic Sensors, Wiley Online Library.","DOI":"10.1201\/9780824744571"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"16522","DOI":"10.3390\/s121216522","article-title":"Recent progress in optical chemical sensors","volume":"12","author":"Qazi","year":"2012","journal-title":"Sensors"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"864","DOI":"10.1109\/JLT.2011.2105462","article-title":"Analytical analysis of side-polished plastic optical fiber as curvature and refractive index sensor","volume":"29","author":"Bilro","year":"2011","journal-title":"J. Lightwave Technol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/S0925-4005(03)00034-0","article-title":"Surface plasmon resonance sensor based on a single-mode polarization-maintaining optical fiber","volume":"90","author":"Piliarik","year":"2003","journal-title":"Sens. Actuators B Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"32502","DOI":"10.1364\/OE.22.032502","article-title":"Optical fiber with nanostructured cladding of TiO2 nanoparticles self-assembled onto a side polished fiber and its temperature sensing","volume":"22","author":"Lu","year":"2014","journal-title":"Opt. Express"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/S0925-4005(00)00718-8","article-title":"Novel spectral fiber optic sensor based on surface plasmon resonance","volume":"74","author":"Homola","year":"2001","journal-title":"Sens. Actuators B Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1016\/j.snb.2014.02.076","article-title":"Side-polished fiber as a sensor for the determination of nematic liquid crystal orientation","volume":"19","author":"Han","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3438","DOI":"10.1364\/AO.31.003438","article-title":"Side-polished fibers","volume":"31","author":"Tseng","year":"1992","journal-title":"Appl. Opt."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"South, I. (2010). Novel D-type fiber optic localized plasmon resonance sensor realized by femtosecond laser engraving. J. Laser Micro\/Nanoeng., 5.","DOI":"10.2961\/jlmn.2010.01.0001"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4794","DOI":"10.3390\/s100504794","article-title":"A multi-D-shaped optical fiber for refractive index sensing","volume":"10","author":"Chen","year":"2010","journal-title":"Sensors"},{"key":"ref_21","unstructured":"Chen, C.H., Tang, J.L., and Wu, W. (2010, January 25\u201328). Novel Multi-D-Shape Fiber Optic Biosensor. Proceedings of the 5th International Symposium on Machinery and Mechatronics for Agriculture and Biosystems Engineering, Fukuoka, Japan."},{"key":"ref_22","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. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.snb.2005.02.034","article-title":"Fiber-optic chemical and biochemical probes based on localized surface plasmon resonance","volume":"11","author":"Chau","year":"2006","journal-title":"Sens. Actuators B Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1016\/j.snb.2012.04.035","article-title":"A polarization-maintaining fiber loop mirror based sensor for liquid refractive index absolute measurement","volume":"16","author":"Zhong","year":"2012","journal-title":"Sens. Actuators B Chem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1673","DOI":"10.1109\/JSEN.2014.2301911","article-title":"D-shaped plastic optical fiber sensor for testing refractive index","volume":"14","author":"Feng","year":"2014","journal-title":"IEEE Sens. J."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"17591","DOI":"10.1364\/OE.19.017591","article-title":"Femtosecond laser fabricated all-optical fiber sensors with ultrahigh refractive index sensitivity: Modeling and experiment","volume":"19","author":"Jiang","year":"2011","journal-title":"Opt. Express"},{"key":"ref_27","first-page":"1","article-title":"Rough side-polished fiber with surface scratches for sensing applications","volume":"73","author":"Zhao","year":"2015","journal-title":"IEEE Photon. J."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1007\/BF00382456","article-title":"Polarization-maintaining fibers","volume":"41","author":"Kaminow","year":"1984","journal-title":"Appl. Sci. Res."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Grattan, K.T.V., and Meggitt, B.T. (2000). Optical Fiber Sensor Technology: Fundamentals, Springer.","DOI":"10.1007\/978-1-4757-6081-1"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.optcom.2012.09.048","article-title":"Temperature-insensitive strain sensor using a fiber loop mirror based on low-birefringence polarization-maintaining fibers","volume":"28","author":"Shen","year":"2013","journal-title":"Opt. Commun."},{"key":"ref_31","first-page":"108","article-title":"High birefringence D-type fibre loop mirror used as refractometer","volume":"13","author":"Marques","year":"2008","journal-title":"Sens. Actuators B Chem."},{"key":"ref_32","unstructured":"Tan, Y.-N., Zhang, Y., Jin, L., and Guan, B.-O. (2012). Asia Pacific Optical Sensors Conference, International Society for Optics and Photonics."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"3974","DOI":"10.1016\/j.ijleo.2015.07.179","article-title":"Simultaneous discrimination of strain and temperature using dual-gratings in one fiber","volume":"126","author":"Jiang","year":"2015","journal-title":"Optik Int. J. Light Electron Opt."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"7045","DOI":"10.1364\/AO.53.007045","article-title":"Simultaneous strain and temperature measurement by cascading few-mode fiber and single-mode fiber long-period fiber gratings","volume":"53","author":"Wang","year":"2014","journal-title":"Appl. Opt."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1016\/j.optcom.2014.12.066","article-title":"Strain and temperature discrimination using a fiber Bragg grating and multimode interference effects","volume":"343","author":"Li","year":"2015","journal-title":"Opt. Commun."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1141","DOI":"10.1109\/LPT.2015.2406572","article-title":"Laser temperature sensor based on a fiber Bragg grating","volume":"27","year":"2015","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/S0030-4018(03)01313-0","article-title":"Strain and temperature sensor using a combination of polymer and silica fibre Bragg gratings","volume":"219","author":"Liu","year":"2003","journal-title":"Opt. Commun."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1859","DOI":"10.1039\/C4AN02230K","article-title":"Simultaneous strain and temperature sensing using a slightly tapered optical fiber with an inner cavity","volume":"140","author":"Chen","year":"2015","journal-title":"Analyst"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1007\/s00340-008-3350-6","article-title":"Temperature-insensitive strain measurement using a birefringent interferometer based on a polarization-maintaining photonic crystal fiber","volume":"95","author":"Han","year":"2009","journal-title":"Appl. Phys. B"},{"key":"ref_40","first-page":"1","article-title":"Study on Dependence of Polarization-Maintaining Photonic Crystal Fiber-Based Polarimetric Strain Sensor on Sensing Fiber Length","volume":"27","author":"Noh","year":"2013","journal-title":"J. Korean Inst. Illum. Electr. Install. Eng."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/9\/1505\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:31:03Z","timestamp":1760211063000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/9\/1505"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,9,15]]},"references-count":40,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2016,9]]}},"alternative-id":["s16091505"],"URL":"https:\/\/doi.org\/10.3390\/s16091505","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,9,15]]}}}