{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T20:56:12Z","timestamp":1774644972448,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2019,9,22]],"date-time":"2019-09-22T00:00:00Z","timestamp":1569110400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51475384"],"award-info":[{"award-number":["51475384"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Xi'an Key Laboratory of Intelligent Detection and Perception","award":["201805061ZD12CG45"],"award-info":[{"award-number":["201805061ZD12CG45"]}]},{"name":"Natural Science Basic Research Project of Shannxi","award":["2016JM6046"],"award-info":[{"award-number":["2016JM6046"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This study presents an extrinsic Fabry\u2013Perot interferometric (EFPI) fiber-optic strain sensor with a very short cavity. The sensor consists of two vertically cut standard single-mode fibers (SMFs) and a glass capillary with a length of several centimeters. The two SMFs penetrate into the glass capillary and are fixed at its two ends with the use of ultraviolet (UV) curable adhesives. Based on the use of the lengthy glass capillary sensitive element, the strain sensitivity can be greatly enhanced. Experiments showed that the microcavity EPFI strain sensor with initial cavity lengths of 20 \u03bcm, 30 \u03bcm, and 40 \u03bcm, and a capillary length of 40 mm, can yield respective cavity length\u2013strain sensitivities of 15.928 nm\/\u03bc\u03b5, 25.281 nm\/\u03bc\u03b5, and 40.178 nm\/\u03bc\u03b5, while its linearity was very close to unity for strain measurements spanning a range in excess of 3500 \u03bc\u03b5. Furthermore, the strain\u2013temperature cross-sensitivity was extremely low.<\/jats:p>","DOI":"10.3390\/s19194097","type":"journal-article","created":{"date-parts":[[2019,9,23]],"date-time":"2019-09-23T03:26:32Z","timestamp":1569209192000},"page":"4097","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Sensitivity-Enhanced Extrinsic Fabry\u2013Perot Interferometric Fiber-Optic Microcavity Strain Sensor"],"prefix":"10.3390","volume":"19","author":[{"given":"Zhibo","family":"Ma","sequence":"first","affiliation":[{"name":"Shaanxi Key Lab of MEMS\/NEMS, Northwestern Polytechnical University, Xi\u2019an 710072, China"},{"name":"Key Lab of Micro\/Nano Systems for Aerospace, Ministry of Education, Northwestern Polytechnical University, Xi\u2019an 710072, China"}]},{"given":"Shaolei","family":"Cheng","sequence":"additional","affiliation":[{"name":"Shaanxi Key Lab of MEMS\/NEMS, Northwestern Polytechnical University, Xi\u2019an 710072, China"},{"name":"Key Lab of Micro\/Nano Systems for Aerospace, Ministry of Education, Northwestern Polytechnical University, Xi\u2019an 710072, China"}]},{"given":"Wanying","family":"Kou","sequence":"additional","affiliation":[{"name":"Xi\u2019an Technological University, School of Optoelectronics Engineering, Xi\u2019an 710021, China"},{"name":"Shaanxi Province Key Lab of Photoelectric Measurement and Instrument Technology, Xi\u2019an Technological University, Xi\u2019an 710021, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2978-7359","authenticated-orcid":false,"given":"Haibin","family":"Chen","sequence":"additional","affiliation":[{"name":"Xi\u2019an Technological University, School of Optoelectronics Engineering, Xi\u2019an 710021, China"},{"name":"Shaanxi Province Key Lab of Photoelectric Measurement and Instrument Technology, Xi\u2019an Technological University, Xi\u2019an 710021, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8501-8036","authenticated-orcid":false,"given":"Wei","family":"Wang","sequence":"additional","affiliation":[{"name":"Xi\u2019an Technological University, School of Optoelectronics Engineering, Xi\u2019an 710021, China"},{"name":"Shaanxi Province Key Lab of Photoelectric Measurement and Instrument Technology, Xi\u2019an Technological University, Xi\u2019an 710021, China"}]},{"given":"Xiongxing","family":"Zhang","sequence":"additional","affiliation":[{"name":"Xi\u2019an Technological University, School of Optoelectronics Engineering, Xi\u2019an 710021, China"},{"name":"Shaanxi Province Key Lab of Photoelectric Measurement and Instrument Technology, Xi\u2019an Technological University, Xi\u2019an 710021, China"}]},{"given":"Tongxin","family":"Guo","sequence":"additional","affiliation":[{"name":"Shaanxi Key Lab of MEMS\/NEMS, Northwestern Polytechnical University, Xi\u2019an 710072, China"},{"name":"Key Lab of Micro\/Nano Systems for Aerospace, Ministry of Education, Northwestern Polytechnical University, Xi\u2019an 710072, China"}]}],"member":"1968","published-online":{"date-parts":[[2019,9,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"737","DOI":"10.1088\/0964-1726\/15\/3\/009","article-title":"A carbon nanotube strain sensor for structural health monitoring","volume":"15","author":"Kang","year":"2006","journal-title":"Smart Mater. Struct."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"630","DOI":"10.1016\/j.conbuildmat.2014.04.105","article-title":"Development of cement-based strain sensor for health monitoring of ultra high strength concrete","volume":"65","author":"Sun","year":"2014","journal-title":"Constr. Build. Mater."},{"key":"ref_3","first-page":"236","article-title":"Health monitoring of an Oregon historical bridge with fiber grating strain sensors","volume":"3671","author":"Seim","year":"1999","journal-title":"Proc. SPIE"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1088\/0964-1726\/9\/2\/306","article-title":"Fiber optic sensors for health monitoring of morphing airframes: I. Bragg grating strain and temperature sensor","volume":"9","author":"Wood","year":"2000","journal-title":"Smart Mater. Struct."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.sna.2016.10.007","article-title":"All-printed strain sensors: Building blocks of the aircraft structural health monitoring system","volume":"253","author":"Zhang","year":"2017","journal-title":"Sens. Actuators A Phys."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1436","DOI":"10.1364\/AO.48.001436","article-title":"Comparing polymer optical fiber, fiber Bragg grating, and traditional strain gauge for aircraft structural health monitoring","volume":"48","author":"Gomez","year":"2009","journal-title":"Appl. Opt."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"3687","DOI":"10.3390\/s110403687","article-title":"Fiber optic sensors for structural health monitoring of air platforms","volume":"11","author":"Guo","year":"2011","journal-title":"Sensors"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1016\/j.compstruct.2008.07.027","article-title":"Structural health monitoring of marine composite structural joints using embedded fiber Bragg grating strain sensors","volume":"89","year":"2009","journal-title":"Compos. Struct."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1364\/OL.18.000072","article-title":"Fiber-optic Bragg grating strain sensor with drift-compensated high-resolution interferometric wavelength-shift detection","volume":"18","author":"Kersey","year":"1993","journal-title":"Opt. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3601","DOI":"10.1364\/AO.32.003601","article-title":"Practical fiber-optic Bragg grating strain gauge system","volume":"32","author":"Melle","year":"1993","journal-title":"Appl. Opt."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"191","DOI":"10.3788\/COL20090703.0191","article-title":"A high sensitive fiber Bragg grating strain sensor with automatic temperature compensation","volume":"7","author":"Li","year":"2009","journal-title":"Chin. Opt. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1159","DOI":"10.1109\/50.939797","article-title":"Corrugated long-period fiber gratings as strain, torsion, and bending sensors","volume":"19","author":"Lin","year":"2001","journal-title":"J. Lightwave Technol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1109\/JQE.2006.886809","article-title":"Strain characteristics of CO2-laser-carved long period fiber gratings","volume":"43","author":"Wang","year":"2007","journal-title":"IEEE J. Quantum Electron"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1109\/LPT.2008.2009360","article-title":"In-line abrupt taper optical fiber Mach\u2013Zehnder interferometric strain sensor","volume":"21","author":"Tian","year":"2009","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.optcom.2013.06.057","article-title":"A strain sensor based on in-line fiber Mach\u2013Zehnder interferometer in twin-core photonic crystal fiber","volume":"309","author":"Qureshi","year":"2013","journal-title":"Opt. Commun."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Dong, X., Du, H., Sun, X., Luo, Z., and Duan, J. (2018). A novel strain sensor with large measurement range based on all fiber Mach\u2013Zehnder interferometer. Sensors, 18.","DOI":"10.3390\/s18051549"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"805","DOI":"10.1109\/JLT.2011.2182498","article-title":"All single-mode fiber Mach\u2013Zehnder interferometer based on two peanut-shape structures","volume":"30","author":"Wu","year":"2012","journal-title":"J. Lightwave Technol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"745","DOI":"10.1088\/0964-1726\/7\/6\/002","article-title":"Measurement and analysis of impact-induced strain using extrinsic fabry-p\u00e9rot fiber optic sensors","volume":"7","author":"Akhavan","year":"1999","journal-title":"Smart Mater. Struct."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1109\/LPT.2007.913335","article-title":"Environmentally stable Fabry\u2013Perot-type strain sensor based on hollow-core photonic bandgap fiber","volume":"20","author":"Shi","year":"2008","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1725","DOI":"10.1109\/LPT.2009.2032662","article-title":"Temperature-insensitive micro Fabry\u2013Perot strain sensor fabricated by chemically etching Er-doped fiber","volume":"21","author":"Gong","year":"2009","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3414","DOI":"10.1364\/OL.31.003414","article-title":"Highly sensitive long-period fiber-grating strain sensor with low temperature sensitivity","volume":"31","author":"Wang","year":"2006","journal-title":"Opt. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"370","DOI":"10.1016\/j.yofte.2005.03.001","article-title":"Temperature-independent fiber Bragg grating strain sensor using bimetal cantilever","volume":"11","author":"Tian","year":"2005","journal-title":"Opt. Fiber Technol. Mater. Devices Syst."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.optcom.2013.01.063","article-title":"Temperature and index insensitive strain sensor based on a photonic crystal fiber in line Mach\u2013Zehnder interferometer","volume":"297","author":"Zheng","year":"2013","journal-title":"Opt. Commun."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2403","DOI":"10.1109\/LPT.2005.857236","article-title":"Intrinsic Fabry\u2013Pe\u00b4rot fiber sensor for temperature and strain measurements","volume":"17","author":"Huang","year":"2005","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1256","DOI":"10.1109\/50.400690","article-title":"In-line fiber etalon (ILFE) fiber-optic strain sensors","volume":"13","author":"Sirkis","year":"1995","journal-title":"J. Lightwave Technol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1329","DOI":"10.1109\/LPT.2008.926948","article-title":"A hollow-core photonic crystal fiber cavity based multiplexed Fabry\u2013Perot interferometric strain sensor system","volume":"20","author":"Shi","year":"2008","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"7112","DOI":"10.1364\/OE.20.007112","article-title":"Spheroidal Fabry\u2013Perot microcavities in optical fibers for high-sensitivity sensing","volume":"20","author":"Favero","year":"2012","journal-title":"Opt. Express"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2121","DOI":"10.1364\/OL.39.002121","article-title":"High-sensitivity strain sensor based on in-fiber improved Fabry\u2013Perot interferometer","volume":"39","author":"Liu","year":"2014","journal-title":"Opt. Lett."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/JPHOT.2014.2319101","article-title":"Temperature-independent ultrasensitive Fabry\u2013Perot all-fiber strain sensor based on a bubble-expanded microcavity","volume":"6","author":"Yin","year":"2014","journal-title":"IEEE Photonics J."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"7624","DOI":"10.1038\/srep07624","article-title":"High-sensitivity strain sensor based on in-fiber rectangular air bubble","volume":"5","author":"Liu","year":"2015","journal-title":"Sci. Rep."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.optcom.2016.10.005","article-title":"In-fiber rectangular air fabry-perot strain sensor based on high-precision fiber cutting platform","volume":"384","author":"Yong","year":"2017","journal-title":"Opt. Commun."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"21946","DOI":"10.1364\/OE.20.021946","article-title":"Towards the control of highly sensitive Fabry-P\u00e9rot strain sensor based on hollow-core ring photonic crystal fiber","volume":"20","author":"Ferreira","year":"2012","journal-title":"Opt. Express"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Tian, J.J., Li, Z.G., Sun, Y.X., and Yao, Y. (2019). High-sensitivity fiber-optic strain sensor based on the Vernier effect and separated Fabry\u2013Perot interferometers. J. Lightwave Technol.","DOI":"10.1109\/JLT.2019.2936174"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"181901","DOI":"10.1063\/1.5058200","article-title":"High-sensitivity strain sensor with an in-fiber air-bubble Fabry-Perot interferometer","volume":"113","author":"Zhou","year":"2018","journal-title":"Appl. Phys. Lett."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"15641","DOI":"10.1364\/OE.19.015641","article-title":"All-fiber long-active-length Fabry\u2013Perot strain sensor","volume":"19","author":"Pevec","year":"2011","journal-title":"Opt. Express"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"7797","DOI":"10.1364\/OE.25.007797","article-title":"Strain force sensor with ultra-high sensitivity based on fiber inline Fabry-Perot micro-cavity plugged by cantilever taper","volume":"25","author":"Liu","year":"2017","journal-title":"Opt. Express"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/19\/4097\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:22:59Z","timestamp":1760188979000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/19\/4097"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,9,22]]},"references-count":36,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2019,10]]}},"alternative-id":["s19194097"],"URL":"https:\/\/doi.org\/10.3390\/s19194097","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,9,22]]}}}