{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T01:44:43Z","timestamp":1760233483391,"version":"build-2065373602"},"reference-count":13,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2021,1,22]],"date-time":"2021-01-22T00:00:00Z","timestamp":1611273600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Portuguese Funding Agency, FCT - Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","award":["Project UIDB\/50014\/2020"],"award-info":[{"award-number":["Project UIDB\/50014\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Optical fiber gratings have long shown their sensing capabilities. One of the main challenges, however, is the interrogation method applied, since typical systems tend to use broadband light sources with optical spectrum analyzers, laser scanning units or CCD (Charged Coupled Device) spectrometers. The following paper presents the development of an interrogation system, which explores the temperature response of a multimode laser diode, in order to interrogate long period fiber gratings. By performing a spectral sweep along one of its rejection bands, a discrete attenuation spectrum is created. Through a curve fitting technique, the original spectrum is restored. The built unit, while presenting a substantially reduced cost compared with typical interrogation systems, is capable of interrogating along a 10 nm window with measurement errors reaching minimum values as low as 0.4 nm, regarding the grating central wavelength, and 0.4 dB for its attenuation. Given its low cost and reduced dimensions, the developed system shows potential for slow-changing field applications.<\/jats:p>","DOI":"10.3390\/s21030749","type":"journal-article","created":{"date-parts":[[2021,1,22]],"date-time":"2021-01-22T11:13:53Z","timestamp":1611314033000},"page":"749","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Development of a Long Period Fiber Grating Interrogation System Using a Multimode Laser Diode"],"prefix":"10.3390","volume":"21","author":[{"given":"Lu\u00eds Henrique","family":"Silva","sequence":"first","affiliation":[{"name":"Faculty of Exact Sciences and Engineering, University of Madeira, Campus da Penteada, 9020-105 Funchal, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3826-7427","authenticated-orcid":false,"given":"Paulo","family":"Santos","sequence":"additional","affiliation":[{"name":"Department of Physics and Astronomy, Faculty of Sciences, University of Porto, R. Campo Alegre 687, 4169-007 Porto, Portugal"},{"name":"INESC TEC\u2014Center of Applied Photonics, R. Campo Alegre 687, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6205-9479","authenticated-orcid":false,"given":"Lu\u00eds C. C.","family":"Coelho","sequence":"additional","affiliation":[{"name":"INESC TEC\u2014Center of Applied Photonics, R. Campo Alegre 687, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1484-2068","authenticated-orcid":false,"given":"Pedro","family":"Jorge","sequence":"additional","affiliation":[{"name":"Department of Physics and Astronomy, Faculty of Sciences, University of Porto, R. Campo Alegre 687, 4169-007 Porto, Portugal"},{"name":"INESC TEC\u2014Center of Applied Photonics, R. Campo Alegre 687, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4111-1095","authenticated-orcid":false,"given":"Jos\u00e9 Manuel","family":"Baptista","sequence":"additional","affiliation":[{"name":"Faculty of Exact Sciences and Engineering, University of Madeira, Campus da Penteada, 9020-105 Funchal, Portugal"},{"name":"INESC TEC\u2014Center of Applied Photonics, R. Campo Alegre 687, 4169-007 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Yasin, M., Harun, S., and Arof, H. (2012). Optical Fiber Sensors: An Overview. Fiber Optic Sensors, InTech. [1st ed.].","DOI":"10.5772\/1379"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Yasin, M., Arof, H., and Harun, S.W. (2015). Writing of Long Period Fiber Gratings Using CO2 Laser Radiation. Advances in Optical Fiber Technology: Fundamental Optical Phenomena and Applications, InTech. [1st ed.].","DOI":"10.5772\/58517"},{"key":"ref_3","unstructured":"Bhatia, V. (1996). Properties and Sensing Applications of Long-Period Gratings. [Ph.D. Thesis, Virginia Polytecnicn Institute and State University]."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"435","DOI":"10.1080\/10739149.2017.1395744","article-title":"Sensitivity-optimized long-period fiber gratings for refractive index and temperature sensing","volume":"46","author":"Du","year":"2018","journal-title":"Instrum. Sci. Technol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1080\/10739149.2018.1493499","article-title":"Mini review: Recent advances in long period fiber grating biological and chemical sensors","volume":"47","author":"Zhao","year":"2019","journal-title":"Instrum. Sci. Technol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1016\/j.optlastec.2017.07.004","article-title":"Highly sensitive torsion sensor based on long period fiber grating fabricated by femtosecond laser pulses","volume":"97","author":"Dong","year":"2017","journal-title":"Opt. Laser Technol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1016\/j.snb.2016.12.050","article-title":"Multi-parameter measurements using optical fibre long period gratings for indoor air quality monitoring","volume":"244","author":"Hromadka","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1771","DOI":"10.1109\/JSEN.2008.2004472","article-title":"Interrogation of a Long Period Grating Fiber Sensor with an Arrayed-Waveguide-Grating-Based Demultiplexer Through Curve Fitting","volume":"8","author":"Guo","year":"2008","journal-title":"IEEE Sens. J."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Dos Santos, P.S.S., Jorge, P.A.S., de Almeida, J., and Coelho, L. (2019). Low-Cost Interrogation System for Long-Period Fiber Gratings Applied to Remote Sensing. Sensors, 19.","DOI":"10.3390\/s19071500"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"4751","DOI":"10.1364\/AO.38.004751","article-title":"Demodulation of fiber Bragg grating sensors based on dynamic tuning of a multimode laser diode","volume":"38","author":"Ferreira","year":"1999","journal-title":"Appl. Opt."},{"key":"ref_11","unstructured":"Burggraaff, O., Perduijn, A.B., van Hek, R.F., Schmidt, N., Keller, C.U., and Snik, F. (May, January 27). A universal smartphone add-on for portable spectroscopy and polarimetry: iSPEX 2. Proceedings of the Micro- and Nanotechnology Sensors, Systems, and Applications XII, Online."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"598","DOI":"10.1016\/j.optcom.2005.09.030","article-title":"Refractive index measurement with long-period gratings arc-induced in pure-silica-core fibres","volume":"259","author":"Rego","year":"2006","journal-title":"Opt. Commun."},{"key":"ref_13","unstructured":"Senior, J.M., and Jamro, M.Y. (2009). Optical Fiber Communications Principles and Practice, Pearson. [3rd ed.]."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/3\/749\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:14:14Z","timestamp":1760159654000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/3\/749"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,22]]},"references-count":13,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2021,2]]}},"alternative-id":["s21030749"],"URL":"https:\/\/doi.org\/10.3390\/s21030749","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2021,1,22]]}}}