{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,4]],"date-time":"2025-12-04T10:00:47Z","timestamp":1764842447481,"version":"build-2065373602"},"reference-count":15,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,2,18]],"date-time":"2021-02-18T00:00:00Z","timestamp":1613606400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Digital"],"abstract":"<jats:p>The traceability of manufactured components is growing in importance with the greater use of digital service solutions offered and with an increased digitalization of manufacturing logistics. In this paper, we investigate the use of image-plane laser speckles as a tool to acquire a unique code from the surface of the component and the ability to use this pattern as a secure component-specific digital fingerprint. Intensity correlation is used as a numerical identifier. Metal sheets of different materials and steel pipes are considered. It is found that laser speckles are robust against surface alterations caused by surface compression and scratching and that the correct pattern reappears from a surface contaminated by oil after cleaning. In this investigation, the detectability is close to 100% for all surfaces considered, with zero false positives. The exception is a heavily oxidized surface wiped by a cotton cloth between recordings. It is further found that the main source for lost detectability is caused by misalignment between the registration and detection geometries where a positive match is lost by a change in angle in the order of 60 mrad. Therefore, as long as the registration and detection systems, respectively, use the same optical arrangement, laser speckles have the ability to serve as unique component identifiers without having to add extra markings or a dedicated sensor to the component.<\/jats:p>","DOI":"10.3390\/digital1010004","type":"journal-article","created":{"date-parts":[[2021,2,18]],"date-time":"2021-02-18T20:56:21Z","timestamp":1613681781000},"page":"54-63","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Robustness of Laser Speckles as Unique Traceable Markers of Metal Components"],"prefix":"10.3390","volume":"1","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4879-8261","authenticated-orcid":false,"given":"Mikael","family":"Sj\u00f6dahl","sequence":"first","affiliation":[{"name":"Department of Engineering Sciences and Mathematics, Lule\u00e5 University of Technology, SE-971 87 Lule\u00e5, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Erik","family":"Olsson","sequence":"additional","affiliation":[{"name":"Department of Engineering Sciences and Mathematics, Lule\u00e5 University of Technology, SE-971 87 Lule\u00e5, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,18]]},"reference":[{"key":"ref_1","unstructured":"Ross, D., Elmenhurst, B., Tocci, M., Forbes, J., and Ross, H.W. (2017). Digital Fingerprinting Track and Trace System. (9 582 714 B2), U.S. Patent."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Wang, M., Wang, C.C., Sepasgozar, S., and Zlatanova, S. (2020). A Systematic Review of Digital Technology Adoption in Off-Site Construction: Current Status and Future Direction towards Industry 4.0. Buildings, 10.","DOI":"10.3390\/buildings10110204"},{"key":"ref_3","unstructured":"Imai, F., and Tin, S.-K. (2014). Material Identification and Discrimination. (2014\/0055775 A1), U.S. Patent."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Dainty, J.C. (1975). Laser Speckle and Related Phenomena, Springer.","DOI":"10.1007\/978-3-662-43205-1"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Goodman, J.W. (2020). Speckle Phenomena in Optics Theory and Applications, SPIE Press. [2nd ed.].","DOI":"10.1117\/3.2548484"},{"key":"ref_6","unstructured":"Sirohi, R.S. (1993). Speckle Metrology, Marcel Dekker."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2753","DOI":"10.1364\/OL.44.005481","article-title":"Interferometry-free noncontact photoacoustic detection method based on speckle correlation change","volume":"44","author":"Li","year":"2019","journal-title":"Opt. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2753","DOI":"10.1117\/1.1797851","article-title":"Measurement of surface roughness by speckle correlation","volume":"43","author":"Yamaguchi","year":"2004","journal-title":"Opt. Eng."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"5948","DOI":"10.1364\/AO.38.005948","article-title":"Corrosion monitoring with speckle correlation","volume":"38","author":"Hinsch","year":"1999","journal-title":"Appl. Opt."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2088","DOI":"10.1364\/JOSAA.25.002088","article-title":"Can laser speckle flowmetry be made a quantitative tool?","volume":"25","author":"Duncan","year":"2008","journal-title":"JOSA A"},{"key":"ref_11","unstructured":"Sutton, M.A., Orteu, J.-J., and Schreier, H.W. (2009). Image Correlation for Shape, Motion and Deformation Measurements, Springer Science+Business Media."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Sj\u00f6dahl, M., and Benckert, L.R. (1993). Electronic speckle photography: Analysis of an algorithm giving the displacement with subpixel accuracy. Appl. Opt., 32.","DOI":"10.1364\/AO.32.002278"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Charrett, T., and Tatam, R. (2019). Performance and Analysis of Feature Tracking Approaches in Laser Speckle Instrumentation. Sensors, 19.","DOI":"10.3390\/s19102389"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Yamaguchi, I. (1981). Speckle displacement and decorrelation in the diffraction and image fields for small object deformation. Opt. Act., 28.","DOI":"10.1080\/713820454"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Sj\u00f6dahl, M. (2013). Dynamic properties of multispectral speckles in digital holography and image correlation. Opt. Eng., 52.","DOI":"10.1117\/1.OE.52.10.101908"}],"container-title":["Digital"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2673-6470\/1\/1\/4\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:25:29Z","timestamp":1760160329000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2673-6470\/1\/1\/4"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,2,18]]},"references-count":15,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2021,3]]}},"alternative-id":["digital1010004"],"URL":"https:\/\/doi.org\/10.3390\/digital1010004","relation":{},"ISSN":["2673-6470"],"issn-type":[{"type":"electronic","value":"2673-6470"}],"subject":[],"published":{"date-parts":[[2021,2,18]]}}}