{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,15]],"date-time":"2025-11-15T17:06:07Z","timestamp":1763226367405,"version":"build-2065373602"},"reference-count":39,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2016,5,31]],"date-time":"2016-05-31T00:00:00Z","timestamp":1464652800000},"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>In this study, a new type of highly sensitive fiber-optic Fabry\u2013Perot interferometer (FFPI) is proposed with a high sensitivity on a wide refractive index (RI) measurement range based on internal reflection mirrors of micro-cavity. The sensor head consists of a single-mode fiber (SMF) with an open micro-cavity. Since light reflections of gold thin films are not affected by the RI of different measuring mediums, the sensor is designed to improve the fringe visibility of optical interference through sputtering the gold films of various thicknesses on the inner surfaces of the micro-cavity, as a semi-transparent mirror (STM) and a total-reflection mirror (TRM). Experiments have been carried out to verify the feasibility of the sensor\u2019s design. It is shown that the fabricated sensor has strong interference visibility exceeding 15 dB over a wide measurement range of RI, and the sensor sensitivity is higher than 1160 nm\/RIU, and RI resolution is better than 1.0 \u00d7 10\u22126 RIU.<\/jats:p>","DOI":"10.3390\/s16060794","type":"journal-article","created":{"date-parts":[[2016,5,31]],"date-time":"2016-05-31T10:40:18Z","timestamp":1464691218000},"page":"794","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":47,"title":["A Highly Sensitive Fiber-Optic Fabry\u2013Perot Interferometer Based on Internal Reflection Mirrors for Refractive Index Measurement"],"prefix":"10.3390","volume":"16","author":[{"given":"Xuefeng","family":"Li","sequence":"first","affiliation":[{"name":"College of Electronic and Information Engineering, Tongji University, Shanghai 201804, China"}]},{"given":"Yujiao","family":"Shao","sequence":"additional","affiliation":[{"name":"College of Electronic and Information Engineering, Tongji University, Shanghai 201804, China"}]},{"given":"Yuan","family":"Yu","sequence":"additional","affiliation":[{"name":"College of Electronic and Information Engineering, Tongji University, Shanghai 201804, China"}]},{"given":"Yin","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Electronic and Information Engineering, Tongji University, Shanghai 201804, China"}]},{"given":"Shaowen","family":"Wei","sequence":"additional","affiliation":[{"name":"College of Electronic and Information Engineering, Tongji University, Shanghai 201804, China"}]}],"member":"1968","published-online":{"date-parts":[[2016,5,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"840","DOI":"10.1126\/science.278.5339.840","article-title":"A porous silicon-based optical interferometric biosensor","volume":"278","author":"Lin","year":"1997","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1038\/nmeth.1221","article-title":"Whispering-gallery-mode biosensing","volume":"5","author":"Vollmer","year":"2008","journal-title":"Nat. Methods"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.bbamem.2013.04.028","article-title":"Surface plasmon resonance spectroscopy for characterisation of membrane protein\u2013ligand interactions and its potential for drug discovery","volume":"1838","author":"Simon","year":"2014","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1021","DOI":"10.1364\/OE.16.001020","article-title":"On the performance quantification of resonant refractive index sensors","volume":"16","author":"White","year":"2008","journal-title":"Opt. Express"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"8601","DOI":"10.3390\/s120708601","article-title":"Recent Progress in Distributed Fiber Optic Sensors","volume":"12","author":"Bao","year":"2012","journal-title":"Sensors"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"5764","DOI":"10.1364\/OE.16.005764","article-title":"Temperature-insensitive miniaturized fiber inline Fabry\u2013Perot interferometer for highly sensitive refractive index measurement","volume":"16","author":"Wei","year":"2008","journal-title":"Opt. Express"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"22813","DOI":"10.1364\/OE.20.022813","article-title":"Optical fiber Fabry\u2013Perot interferometer cavity fabricated by femtosecond laser micromachining and fusion splicing for refractive index sensing","volume":"20","author":"Liao","year":"2012","journal-title":"Opt. Express"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"7451","DOI":"10.3390\/s140407451","article-title":"Chronology of Fabry\u2013Perot Interferometer Fiber-Optic Sensors and Their Applications: A Review","volume":"14","author":"Lim","year":"2014","journal-title":"Sensors"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"151122","DOI":"10.1063\/1.1904716","article-title":"Highly sensitive fiber Bragg grating refractive index sensors","volume":"86","author":"Liang","year":"2005","journal-title":"Appl. Phys. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"18452","DOI":"10.1364\/OE.19.018452","article-title":"Demonstration of a compact temperature sensor based on first-order Bragg grating in a tapered fiber probe","volume":"19","author":"Kou","year":"2011","journal-title":"Opt. Express"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"044105","DOI":"10.1063\/1.2838349","article-title":"Long-period gratings inscribed in air- and water-filled photonic crystal fiber for refractometric sensing of aqueous solution","volume":"92","author":"He","year":"2008","journal-title":"Appl. Phys. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"081101","DOI":"10.1063\/1.3493111","article-title":"Review of long period fiber gratings written by CO2 laser","volume":"108","author":"Wang","year":"2010","journal-title":"J. Appl. Phys."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1136","DOI":"10.1364\/BOE.5.001136","article-title":"Non-invasive respiratory monitoring using long-period fiber grating sensors","volume":"5","author":"Petrovic","year":"2014","journal-title":"Biomed. Opt. Express"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"21693","DOI":"10.1364\/OE.20.021693","article-title":"Tapered optical fiber sensor based on localized surface plasmon resonance","volume":"20","author":"Lin","year":"2012","journal-title":"Opt. Express"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"27023","DOI":"10.1364\/OE.21.027023","article-title":"Dengue immunoassay with an LSPR fiber optic sensor","volume":"21","author":"Camara","year":"2013","journal-title":"Opt. Express"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"18701","DOI":"10.3390\/s141018701","article-title":"Optical Fiber Sensor Based on Localized Surface Plasmon Resonance Using Silver Nanoparticles Photodeposited on the Optical Fiber End","volume":"14","year":"2014","journal-title":"Sensors"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1872","DOI":"10.1109\/LPT.2012.2217738","article-title":"Ultrahigh Sensitivity Refractive Index Sensor Based on Optical Microfiber","volume":"24","author":"Ji","year":"2012","journal-title":"IEEE Photo. Tech. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"14200","DOI":"10.3390\/s131014200","article-title":"A Highly Sensitive Fiber Optic Sensor Based on Two-Core Fiber for Refractive Index Measurement","volume":"13","year":"2013","journal-title":"Sensors"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"5823","DOI":"10.3390\/s140405823","article-title":"Microfiber Optical Sensors: A Review","volume":"14","author":"Tong","year":"2014","journal-title":"Sensors"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"17106","DOI":"10.3390\/s150717106","article-title":"An Exposed-Core Grapefruit Fibers Based Surface Plasmon Resonance Sensor","volume":"15","author":"Lu","year":"2015","journal-title":"Sensors"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/j.sna.2008.06.030","article-title":"In-line fiber Fabry\u2013Perot refractive-index tip sensor based on endlessly photonic crystal fiber","volume":"148","author":"Rao","year":"2008","journal-title":"Sens. Actuators A Phys."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2252","DOI":"10.1364\/OE.16.002252","article-title":"Laser-micromachined Fabry\u2013Perot optical fiber tip sensor for high-resolution temperature-independent measurement of refractive index","volume":"16","author":"Ran","year":"2008","journal-title":"Optics Express"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"14245","DOI":"10.1364\/OE.18.014245","article-title":"Miniaturized fiber taper reflective interferometer for high temperature measurement","volume":"18","author":"Kou","year":"2010","journal-title":"Opt. Express"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"14123","DOI":"10.1364\/OE.15.014123","article-title":"Micro Fabry\u2013Perot interferometers in silica fibers machined by femtosecond laser","volume":"15","author":"Rao","year":"2007","journal-title":"Opt. Express"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1109\/JPHOT.2011.2181943","article-title":"Fiber-Optic Temperature Sensor Based on Difference of Thermal Expansion Coefficient between Fused Silica and Metallic Materials","volume":"4","author":"Li","year":"2012","journal-title":"IEEE Photon. J."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"06FL10","DOI":"10.1143\/JJAP.51.06FL10","article-title":"High-Sensitivity Fiber-Optic Fabry\u2013Perot Interferometer Temperature Sensor","volume":"51","author":"Li","year":"2012","journal-title":"Jpn. J. Appl. Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1016\/j.sna.2004.08.029","article-title":"Monitoring changes in the refractive index of gases by means of a fiber optic Fabry\u2013Perot interferometer sensor","volume":"118","author":"Xiao","year":"2005","journal-title":"Sensor Actuat. A Phys."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"25333","DOI":"10.1364\/OE.22.025333","article-title":"Reflectivity enhanced refractive index sensor based on a fiber-integrated Fabry\u2013Perot microresonator","volume":"22","author":"Wieduwilt","year":"2014","journal-title":"Opt. Express"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"16241","DOI":"10.1364\/OE.22.016241","article-title":"High resolution, all-fiber, micro-machined sensor for simultaneous measurement of refractive index and temperature","volume":"22","author":"Pevec","year":"2014","journal-title":"Opt. Express"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1007\/BF00323913","article-title":"Optical and electrical properties of optimized thin gold films as top layer of MIS solar cells","volume":"54","author":"Khan","year":"1992","journal-title":"Appl. Phys. A."},{"key":"ref_31","first-page":"85","article-title":"Fabrication of Two-Axis Quartz MEMS-Based Capacitive Tilt Sensor","volume":"128","author":"Liang","year":"2008","journal-title":"J. Inst. Electr. Eng. Jpn."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"06GM01","DOI":"10.1143\/JJAP.50.06GM01","article-title":"Doubled optical path length for photonic bandgap fiber gas cell using micromirror","volume":"50","author":"Li","year":"2011","journal-title":"Jpn. J. Appl. Phys."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"703","DOI":"10.1002\/j.1538-7305.1977.tb00534.x","article-title":"Loss analysis of single-mode fiber splices","volume":"56","author":"Marcuse","year":"1977","journal-title":"Bell Syst. Tech. J."},{"key":"ref_34","first-page":"279","article-title":"Loss analysis of single mode telecommunication fiber thermally-diffused core areas","volume":"27","author":"Marek","year":"2007","journal-title":"Optica Applicate"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"21757","DOI":"10.1364\/OE.22.021757","article-title":"In-line open-cavity Fabry\u2013P\u00e9rot interferometer formed by C-shaped fiber fortemperature-insensitive refractive index sensing","volume":"22","author":"Wu","year":"2014","journal-title":"Opt. Express"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1364\/OL.36.000412","article-title":"High-pressure and high-temperature characteristics of a Fabry\u2013Perot interferometer based on photonic crystal fiber","volume":"36","author":"Wu","year":"2011","journal-title":"Opt. Lett."},{"key":"ref_37","unstructured":"Data Sheet of Shin-Etsu Chemical Homepage. Available online: http:\/\/www.shinetsusilicone-global.com\/catalog\/pdf\/grease_e.pdf."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1007\/s00170-013-4744-0","article-title":"Applied Technique of Focused Ion Beam Milling Based on Microstructure of Photonic Bandgap Fiber","volume":"68","author":"Li","year":"2013","journal-title":"Int. J. Adv. Manuf. Tech."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"06FK05","DOI":"10.1143\/JJAP.48.06FK05","article-title":"Fabrication of photonic bandgap fiber gas cell using focused ion beam cutting","volume":"48","author":"Li","year":"2009","journal-title":"Jpn. J. Appl. Phys."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/6\/794\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:24:45Z","timestamp":1760210685000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/6\/794"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,5,31]]},"references-count":39,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2016,6]]}},"alternative-id":["s16060794"],"URL":"https:\/\/doi.org\/10.3390\/s16060794","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2016,5,31]]}}}