{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,27]],"date-time":"2025-10-27T20:43:31Z","timestamp":1761597811950,"version":"build-2065373602"},"reference-count":28,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2017,4,18]],"date-time":"2017-04-18T00:00:00Z","timestamp":1492473600000},"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 work, fibre Bragg gratings (FBGs) were inscribed in two different undoped poly- (methyl methacrylate) (PMMA) polymer optical fibres (POFs) using different types of UV lasers and their inscription times, temperature and strain sensitivities are investigated. The POF Bragg gratings (POFBGs) were inscribed using two UV lasers: a continuous UV HeCd @325 nm laser and a pulsed UV KrF @248 nm laser. Two PMMA POFs are used in which the primary and secondary preforms (during the two-step drawing process) have a different thermal treatment. The PMMA POFs drawn in which the primary or secondary preform is not specifically pre-treated need longer inscription time than the fibres drawn where both preforms have been pre-annealed at 80 \u00b0C for 2 weeks. Using both UV lasers, for the latter fibre much less inscription time is needed compared to another homemade POF. The properties of a POF fabricated with both preforms thermally well annealed are different from those in which just one preform step process is thermally treated, with the first POFs being much less sensitive to thermal treatment. The influence of annealing on the strain and temperature sensitivities of the fibres prior to FBG inscription is also discussed, where it is observed that the fibre produced from a two-step drawing process with well-defined pre-annealing of both preforms did not produce any significant difference in sensitivity. The results indicate the impact of preform thermal pre-treatment before the PMMA POFs drawing, which can be an essential characteristic in the view of developing POF sensors technology.<\/jats:p>","DOI":"10.3390\/s17040891","type":"journal-article","created":{"date-parts":[[2017,4,18]],"date-time":"2017-04-18T11:22:04Z","timestamp":1492514524000},"page":"891","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":70,"title":["Fast Bragg Grating Inscription in PMMA Polymer Optical Fibres: Impact of Thermal Pre-Treatment of Preforms"],"prefix":"10.3390","volume":"17","author":[{"given":"Carlos","family":"Marques","sequence":"first","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es and Physics Department &amp; I3N, Universidade de Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"},{"name":"Aston Institute of Photonic Technologies, Aston University, Aston Triangle, B4 7ET Birmingham, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4866-1361","authenticated-orcid":false,"given":"Andreas","family":"Pospori","sequence":"additional","affiliation":[{"name":"Aston Institute of Photonic Technologies, Aston University, Aston Triangle, B4 7ET Birmingham, UK"}]},{"given":"G\u00f6khan","family":"Demirci","sequence":"additional","affiliation":[{"name":"Department of Polymer Chemistry, Maria Curie-Sklodowska University, 20-031 Lublin, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5409-6923","authenticated-orcid":false,"given":"Onur","family":"\u00c7etinkaya","sequence":"additional","affiliation":[{"name":"Laboratory of Optical Fibre Technology, Maria Curie-Sklodowska University, 20-031 Lublin, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4856-0309","authenticated-orcid":false,"given":"Barbara","family":"Gawdzik","sequence":"additional","affiliation":[{"name":"Department of Polymer Chemistry, Maria Curie-Sklodowska University, 20-031 Lublin, Poland"}]},{"given":"Paulo","family":"Antunes","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es and Physics Department &amp; I3N, Universidade de Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"given":"Ole","family":"Bang","sequence":"additional","affiliation":[{"name":"Laboratory of Optical Fibre Technology, Maria Curie-Sklodowska University, 20-031 Lublin, Poland"}]},{"given":"Pawel","family":"Mergo","sequence":"additional","affiliation":[{"name":"Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark"}]},{"given":"Paulo","family":"Andr\u00e9","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es and Department of Electrical and Computer Engineering, Instituto Superior T\u00e9cnico, University of Lisbon, 1049-001 Lisbon, Portugal"}]},{"given":"David","family":"Webb","sequence":"additional","affiliation":[{"name":"Aston Institute of Photonic Technologies, Aston University, Aston Triangle, B4 7ET Birmingham, UK"}]}],"member":"1968","published-online":{"date-parts":[[2017,4,18]]},"reference":[{"doi-asserted-by":"crossref","unstructured":"Shao, Y., Cao, R., Huang, Y.K., Ji, P.N., and Zhang, S. (2012, January 4\u20138). 112-Gb\/s transmission over 100 m of graded-index POF for optical data center applications. Proceedings of the Optical Fibre Communication Conference (OFC), Los Angeles, CA, USA.","key":"ref_1","DOI":"10.1364\/OFC.2012.OW3J.5"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"9564","DOI":"10.1364\/OE.20.009564","article-title":"Characterization and modeling of Bragg gratings written in polymer fibre for use as filters in the THz region","volume":"20","author":"Zhou","year":"2012","journal-title":"Opt. Express"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"092004","DOI":"10.1088\/0957-0233\/26\/9\/092004","article-title":"Fibre Bragg grating sensors in polymer optical fibres","volume":"26","author":"Webb","year":"2015","journal-title":"Meas. Sci. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1016\/j.yofte.2017.03.010","article-title":"Polymer optical fiber sensors in human life safety","volume":"36","author":"Marques","year":"2017","journal-title":"Opt. Fiber Technol."},{"key":"ref_5","first-page":"303","article-title":"Intrinsic polymer optical fibre sensors for high-strain applications","volume":"6167","author":"Kiesel","year":"2005","journal-title":"Smart Struct. Mater."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1551","DOI":"10.1109\/JLT.2013.2254110","article-title":"Acousto-Optic effect in microstructured polymer fibre Bragg gratings: Simulation and experimental overview","volume":"31","author":"Marques","year":"2013","journal-title":"IEEE\/OSA J. Lightw. Technol."},{"unstructured":"Wang, T.X., Luo, Y.H., Peng, G.D., and Zhang, Q. (February, January 31). High-sensitivity stress sensor based on Bragg grating in BDK-doped photosensitive polymer optical fibre. Proceedings of the 3rd Asia Pacific Optical Sensors Conference, Sydney, Australia.","key":"ref_7"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6058","DOI":"10.1364\/OE.23.006058","article-title":"Highly sensitive liquid level monitoring system utilizing polymer fibre Bragg gratings","volume":"23","author":"Marques","year":"2015","journal-title":"Opt. Express"},{"key":"ref_9","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_10","first-page":"8","article-title":"High-sensitivity temperature sensor based on Bragg grating in BDK-doped photosensitive polymer optical fibre","volume":"9","author":"Cheng","year":"2011","journal-title":"Chin. Opt. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1090","DOI":"10.1109\/JLT.2011.2169941","article-title":"Investigation into time response of polymer fibre Bragg grating based humidity sensors","volume":"30","author":"Zhang","year":"2012","journal-title":"IEEE\/OSA J. Lightw. Technol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4581","DOI":"10.1364\/OE.23.004581","article-title":"Polarization effects in polymer FBGs: Study and use for transverse force sensing","volume":"23","author":"Hu","year":"2015","journal-title":"Opt. Express"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.optcom.2013.05.059","article-title":"Narrow bandwidth Bragg gratings imprinted in polymer optical fibres for different spectral windows","volume":"307","author":"Marques","year":"2013","journal-title":"Opt. Commun."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3769","DOI":"10.1364\/OL.38.003769","article-title":"Highly photosensitive polymethyl methacrylate microstructured polymer optical fibre with doped core","volume":"38","author":"Nielsen","year":"2013","journal-title":"Opt. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"19731","DOI":"10.1364\/OE.19.019731","article-title":"Humidity insensitive TOPAS polymer fibre Bragg grating sensor","volume":"19","author":"Yuan","year":"2011","journal-title":"Opt. Express"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"693","DOI":"10.1109\/LPT.2014.2386692","article-title":"Femtosecond laser inscribed Bragg gratings in low loss CYTOP polymer optical fibre","volume":"27","author":"Lacraz","year":"2015","journal-title":"IEEE Photonics Technol. Lett."},{"doi-asserted-by":"crossref","unstructured":"Oliveira, R., Marques, C.A.F., Bilro, L., and Nogueira, R.N. (2014, January 2\u20136). Production and characterization of Bragg gratings in polymer optical fibres for sensors and optical communications. Proceedings of the 23rd International Conference on Optical Fibre Sensors, Santander, Spain.","key":"ref_17","DOI":"10.1117\/12.2058861"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"10181","DOI":"10.1364\/OE.23.010181","article-title":"Bragg gratings in a few mode microstructured polymer optical fibre in less than 30 s","volume":"23","author":"Oliveira","year":"2015","journal-title":"Opt. Express"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"660","DOI":"10.1109\/LPT.2011.2125786","article-title":"Narrow bandwidth 850-nm fibre Bragg gratings in few-mode polymer optical fibres","volume":"23","author":"Stefani","year":"2011","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1148","DOI":"10.1109\/LPT.2012.2197194","article-title":"Direct writing of fibre Bragg grating in microstructured polymer optical fibre","volume":"24","author":"Stefani","year":"2012","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"5270","DOI":"10.1364\/OE.22.005270","article-title":"Bragg grating writing in PMMA microstructured polymer optical fibres in less than 7 min","volume":"22","author":"Bundalo","year":"2014","journal-title":"Opt. Express"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/j.yofte.2011.02.005","article-title":"Analysis of multimode POF gratings in stress and strain sensing applications","volume":"17","author":"Luo","year":"2011","journal-title":"Opt. Fibre Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"500","DOI":"10.1109\/LPT.2017.2662219","article-title":"Chirped Bragg gratings in PMMA step-index polymer optical fiber","volume":"29","author":"Marques","year":"2017","journal-title":"IEEE Photonics Technol. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3421","DOI":"10.1364\/OL.39.003421","article-title":"Photosensitivity mechanism of undoped poly(methyl methacrylate) under UV radiation at 325 nm and its spatial resolution limit","volume":"39","author":"Nielsen","year":"2014","journal-title":"Opt. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2517","DOI":"10.1364\/OL.41.002517","article-title":"Thermal effects on the photoelastic coefficient of polymer optical fibres","volume":"41","author":"Acheroy","year":"2016","journal-title":"Opt. Lett."},{"unstructured":"Marques, C.A.F., Pospori, A., S\u00e1ez-Rodr\u00edguez, D., Nielsen, K., Bang, O., and Webb, D.J. (October, January 28). Fibre optic liquid level monitoring system using microstructured polymer fibre Bragg grating array sensors: Performance analysis. Proceedings of the 24th International Conference on Optical Fibre Sensors, Curitiba, Brazil.","key":"ref_26"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1206","DOI":"10.1364\/OE.24.001206","article-title":"Temperature insensitive hysteresis free highly sensitive polymer optical fibre Bragg grating humidity sensor","volume":"24","author":"Woyessa","year":"2016","journal-title":"Opt. Express"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/j.optcom.2010.08.069","article-title":"Improved thermal and strain performance of annealed polymer optical fibre Bragg gratings","volume":"284","author":"Yuan","year":"2011","journal-title":"Opt. Commun."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/4\/891\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:32:54Z","timestamp":1760207574000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/4\/891"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,4,18]]},"references-count":28,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2017,4]]}},"alternative-id":["s17040891"],"URL":"https:\/\/doi.org\/10.3390\/s17040891","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2017,4,18]]}}}