{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T15:56:22Z","timestamp":1785426982688,"version":"3.56.0"},"reference-count":31,"publisher":"Optica Publishing Group","issue":"6","license":[{"start":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T00:00:00Z","timestamp":1773187200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/doi.org\/10.1364\/OA_License_v2#VOR-OA"},{"start":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T00:00:00Z","timestamp":1773187200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/opg.optica.org\/policies\/opg-tdm-policy.json"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2025YFE0217500"],"award-info":[{"award-number":["2025YFE0217500"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2024YFA1208900"],"award-info":[{"award-number":["2024YFA1208900"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["62274014"],"award-info":[{"award-number":["62274014"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["62235016"],"award-info":[{"award-number":["62235016"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["opg.optica.org"],"crossmark-restriction":false},"short-container-title":["Opt. Express"],"published-print":{"date-parts":[[2026,3,23]]},"abstract":"<jats:p>\n                    Terahertz quantum cascade lasers (THz QCL) based on self-mixing offer great potential for high-resolution spectroscopy and imaging, yet their practical application is hindered by the low accuracy and signal-to-noise ratio (SNR) using traditional Fourier techniques. To address this issue, we propose a hybrid denoising framework combining wavelet pre-processing and a peak-aware U-Net network to restore multimode THz QCL spectra with enhanced SNR and reduced error factor. The wavelet transform first removes high-frequency noise, while the subsequent U-Net reconstructs spectral details and enhances peaks via a dedicated peak-aware mechanism. Experimental results demonstrate that our method achieves an SNR enhancement by \u223c 10 dB, a determination coefficient of 0.979, and a reconstruction error of 3.7\u2009\u00d7\u200910\n                    <jats:sup>\u22125<\/jats:sup>\n                    , significantly outperforming the original data. Validation on methanol gas transmission spectra further confirms the ability of the model to accurately recover the characteristic spectral information. This work illustrates the strong capability of deep learning-assisted signal processing in advancing THz spectroscopic sensing toward high accuracy and robustness.\n                  <\/jats:p>","DOI":"10.1364\/oe.584140","type":"journal-article","created":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T04:00:09Z","timestamp":1772683209000},"page":"9753","update-policy":"https:\/\/doi.org\/10.1364\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["U-Net-based deep learning enabling denoised spectroscopy for terahertz quantum cascade laser"],"prefix":"10.1364","volume":"34","author":[{"given":"Yanan","family":"Zhao","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/04nqf9k60","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Institute of Physics, Chinese Academy of Sciences"},{"name":"University of Chinese Academy of Sciences"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zejun","family":"Ma","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/04nqf9k60","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Institute of Physics, Chinese Academy of Sciences"},{"name":"University of Chinese Academy of Sciences"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yingjun","family":"Han","sequence":"additional","affiliation":[{"name":"Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Quanyong","family":"Lu","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/04nqf9k60","id-type":"ROR","asserted-by":"publisher"}]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"285","published-online":{"date-parts":[[2026,3,11]]},"reference":[{"key":"oe-34-6-9753-R1","doi-asserted-by":"publisher","first-page":"553","DOI":"10.1126\/science.264.5158.553","type":"journal-article","volume":"264","author":"Faist","year":"1994","journal-title":"Science"},{"key":"oe-34-6-9753-R2","doi-asserted-by":"publisher","first-page":"8462","DOI":"10.1364\/OE.23.008462","type":"journal-article","volume":"23","author":"Razeghi","year":"2015","journal-title":"Opt. Express"},{"key":"oe-34-6-9753-R3","doi-asserted-by":"publisher","first-page":"15181","DOI":"10.1364\/OE.393069","type":"journal-article","volume":"28","author":"Lu","year":"2020","journal-title":"Opt. Express"},{"key":"oe-34-6-9753-R4","doi-asserted-by":"publisher","first-page":"985","DOI":"10.1364\/OPTICA.559884","type":"journal-article","volume":"12","author":"Fuchsberger","year":"2025","journal-title":"Optica"},{"key":"oe-34-6-9753-R5","doi-asserted-by":"publisher","first-page":"14637","DOI":"10.1021\/acs.analchem.5c02177","type":"journal-article","volume":"97","author":"Huan","year":"2025","journal-title":"Anal. Chem."},{"key":"oe-34-6-9753-R6","doi-asserted-by":"publisher","first-page":"37614","DOI":"10.1364\/OE.569968","type":"journal-article","volume":"33","author":"Lepage","year":"2025","journal-title":"Opt. Express"},{"key":"oe-34-6-9753-R7","doi-asserted-by":"publisher","first-page":"161101","DOI":"10.1063\/5.0144705","type":"journal-article","volume":"122","author":"Khalatpour","year":"2023","journal-title":"Appl. Phys. Lett."},{"key":"oe-34-6-9753-R8","doi-asserted-by":"publisher","first-page":"799","DOI":"10.1049\/el.2017.0662","type":"journal-article","volume":"53","author":"Li","year":"2017","journal-title":"Electron. Lett."},{"key":"oe-34-6-9753-R9","doi-asserted-by":"publisher","first-page":"16227","DOI":"10.1038\/s41598-024-62787-5","type":"journal-article","volume":"14","author":"Schiattarella","year":"2024","journal-title":"Sci. Rep."},{"key":"oe-34-6-9753-R10","doi-asserted-by":"publisher","first-page":"325","DOI":"10.1007\/s10762-013-9973-7","type":"journal-article","volume":"34","author":"H\u00fcbers","year":"2013","journal-title":"J. Infrared, Millimeter, Terahertz Waves"},{"key":"oe-34-6-9753-R11","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1109\/JSEN.2012.2218594","type":"journal-article","volume":"13","author":"Valavanis","year":"2013","journal-title":"IEEE Sens. J."},{"key":"oe-34-6-9753-R12","doi-asserted-by":"publisher","first-page":"112431","DOI":"10.1016\/j.optlastec.2025.112431","type":"journal-article","volume":"184","author":"Xu","year":"2025","journal-title":"Opt. Laser Technol."},{"key":"oe-34-6-9753-R13","doi-asserted-by":"publisher","first-page":"6148","DOI":"10.1016\/j.ijleo.2014.06.124","type":"journal-article","volume":"125","author":"Li","year":"2014","journal-title":"Optik"},{"key":"oe-34-6-9753-R14","doi-asserted-by":"publisher","first-page":"645","DOI":"10.1039\/a608255f","type":"journal-article","volume":"122","author":"Alsberg","year":"1997","journal-title":"Analyst"},{"key":"oe-34-6-9753-R15","first-page":"385","article-title":"A denoising method based on CNN for the measurement of far-field focal spot of high power laser using schlieren method","volume":"11567","author":"Li","year":"2020"},{"key":"oe-34-6-9753-R16","doi-asserted-by":"publisher","first-page":"112768","DOI":"10.1016\/j.optlastec.2025.112768","type":"journal-article","volume":"186","author":"Cheng","year":"2025","journal-title":"Opt. Laser Technol."},{"key":"oe-34-6-9753-R17","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1109\/LGRS.2024.3496482","type":"journal-article","volume":"22","author":"Ma","year":"2025","journal-title":"IEEE Geosci. Remote Sensing Lett."},{"key":"oe-34-6-9753-R18","doi-asserted-by":"publisher","first-page":"7410","DOI":"10.1109\/JSEN.2023.3246178","type":"journal-article","volume":"23","author":"Liu","year":"2023","journal-title":"IEEE Sens. J."},{"key":"oe-34-6-9753-R19","doi-asserted-by":"publisher","first-page":"7236","DOI":"10.1038\/s41598-017-07432-0","type":"journal-article","volume":"7","author":"Keeley","year":"2017","journal-title":"Sci. Rep."},{"key":"oe-34-6-9753-R20","doi-asserted-by":"publisher","first-page":"14246","DOI":"10.1364\/OE.390433","type":"journal-article","volume":"28","author":"Qi","year":"2020","journal-title":"Opt. Express"},{"key":"oe-34-6-9753-R21","doi-asserted-by":"publisher","first-page":"570","DOI":"10.1364\/AOP.7.000570","type":"journal-article","volume":"7","author":"Taimre","year":"2015","journal-title":"Adv. Opt. Photonics"},{"key":"oe-34-6-9753-R22","doi-asserted-by":"publisher","first-page":"3265","DOI":"10.1007\/s11760-023-02541-y","type":"journal-article","volume":"17","author":"Lan","year":"2023","journal-title":"Signal Image Video Process."},{"key":"oe-34-6-9753-R23","doi-asserted-by":"publisher","first-page":"5486","DOI":"10.1002\/jsfa.13381","type":"journal-article","volume":"104","author":"You","year":"2024","journal-title":"J. Sci. Food Agric."},{"key":"oe-34-6-9753-R24","doi-asserted-by":"publisher","first-page":"116549","DOI":"10.1016\/j.image.2021.116549","type":"journal-article","volume":"101","author":"Kumar","year":"2022","journal-title":"Signal Process. Image Commun."},{"key":"oe-34-6-9753-R25","doi-asserted-by":"publisher","first-page":"1428","DOI":"10.1109\/JQE.2011.2169653","type":"journal-article","volume":"47","author":"Donati","year":"2011","journal-title":"IEEE J. Quantum Electron."},{"key":"oe-34-6-9753-R26","doi-asserted-by":"publisher","first-page":"14648","DOI":"10.1021\/acsomega.3c00518","type":"journal-article","volume":"8","author":"Chi","year":"2023","journal-title":"ACS Omega"},{"key":"oe-34-6-9753-R27","doi-asserted-by":"publisher","first-page":"107682","DOI":"10.1016\/j.future.2024.107682","type":"journal-article","volume":"166","author":"Dagal","year":"2025","journal-title":"Future Gener. Comput. Syst."},{"key":"oe-34-6-9753-R29","doi-asserted-by":"publisher","first-page":"3466","DOI":"10.1364\/JOSAB.435225","type":"journal-article","volume":"38","author":"Leng","year":"2021","journal-title":"J. Opt. Soc. Am. B"},{"key":"oe-34-6-9753-R30","doi-asserted-by":"publisher","first-page":"5933","DOI":"10.1364\/OL.43.005933","type":"journal-article","volume":"43","author":"Han","year":"2018","journal-title":"Opt. Lett."},{"key":"oe-34-6-9753-R31","doi-asserted-by":"publisher","first-page":"2225","DOI":"10.1364\/OL.43.002225","type":"journal-article","volume":"43","author":"Chhantyal-Pun","year":"2018","journal-title":"Opt. Lett."},{"key":"oe-34-6-9753-R32","doi-asserted-by":"publisher","author":"Zhao","year":"2026","DOI":"10.5281\/zenodo.18502941","type":"software"}],"container-title":["Optics Express"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/opg.optica.org\/viewmedia.cfm?URI=oe-34-6-9753&seq=0","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T13:09:12Z","timestamp":1778677752000},"score":1,"resource":{"primary":{"URL":"https:\/\/opg.optica.org\/abstract.cfm?URI=oe-34-6-9753"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,11]]},"references-count":31,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026]]},"published-print":{"date-parts":[[2026]]}},"URL":"https:\/\/doi.org\/10.1364\/oe.584140","relation":{},"ISSN":["1094-4087"],"issn-type":[{"value":"1094-4087","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,11]]},"assertion":[{"value":"Optica Publishing Group","name":"publisher","label":"This article is maintained by"},{"value":"https:\/\/doi.org\/10.1364\/OE.584140","name":"articlelink","label":"Crossref DOI link to publisher maintained version"},{"value":"research-article","name":"content_type","label":"Article type"},{"value":"Screened by Similarity Check","name":"cross_check","label":"Similarity check"},{"value":"Yes","order":0,"name":"peer_reviewed","label":"Peer reviewed","group":{"name":"peer_review","label":"Peer review"}},{"value":"Single blind","order":1,"name":"review_process","label":"Review process","group":{"name":"peer_review","label":"Peer review"}},{"value":"10 November 2025","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"4 March 2026","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"11 March 2026","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}},{"value":"\u00a9 2026 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement","name":"copyright","label":"Copyright"}]}}