{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T14:18:30Z","timestamp":1769696310238,"version":"3.49.0"},"reference-count":44,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2021,11,17]],"date-time":"2021-11-17T00:00:00Z","timestamp":1637107200000},"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>We developed a cavity ringdown spectrometer by utilizing a step-scanning and dithering method for matching laser wavelengths to optical resonances of an optical cavity. Our approach is capable of working with two and more lasers for quasi-simultaneous measurements of multiple gas species. The developed system was tested with two lasers operating around 1654 nm and 1658 nm for spectral detections of 12CH4 and its isotope 13CH4 in air, respectively. The ringdown time of the empty cavity was about 340 \u00b5s. The achieved high detection sensitivity of a noise-equivalent absorption coefficient was 2.8 \u00d7 10\u221211 cm\u22121 Hz\u22121\/2 or 1 \u00d7 10\u221211 cm\u22121 by averaging for 30 s. The uncertainty of the high precision determination of \u03b413CH4 in air is about 1.3\u2030. Such a system will be useful for future applications such as environmental monitoring.<\/jats:p>","DOI":"10.3390\/s21227622","type":"journal-article","created":{"date-parts":[[2021,11,17]],"date-time":"2021-11-17T09:16:11Z","timestamp":1637140571000},"page":"7622","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Quasi-Simultaneous Sensitive Detection of Two Gas Species by Cavity-Ringdown Spectroscopy with Two Lasers"],"prefix":"10.3390","volume":"21","author":[{"given":"Guosheng","family":"Ma","sequence":"first","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China"},{"name":"Graduate School of Science Island Branch, University of Science and Technology of China, Hefei 230026, China"}]},{"given":"Yabai","family":"He","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China"}]},{"given":"Bing","family":"Chen","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China"}]},{"given":"Hao","family":"Deng","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China"}]},{"given":"Ying","family":"Liu","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China"},{"name":"Graduate School of Science Island Branch, University of Science and Technology of China, Hefei 230026, China"}]},{"given":"Xingping","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Engineering Science, University of Science and Technology of China, Hefei 230026, China"}]},{"given":"Zhihao","family":"Zhao","sequence":"additional","affiliation":[{"name":"College of Information Science and Engineering, Northeastern University, Shenyang 110819, China"}]},{"given":"Ruifeng","family":"Kan","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1221","DOI":"10.1089\/ast.2018.1917","article-title":"Methane on Mars and habitability: Challenges and responses","volume":"18","author":"Yung","year":"2018","journal-title":"Astrobiology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1016\/S0012-8252(01)00062-9","article-title":"Atmospheric methane and global change","volume":"57","author":"Wuebbles","year":"2002","journal-title":"Earth-Sci. Rev."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1146\/annurev.eg.15.110190.000413","article-title":"The future of methane as an energy resource","volume":"15","author":"MacDonald","year":"1990","journal-title":"Annu. Rev. Energy"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1111\/j.1574-6976.1999.tb00390.x","article-title":"Enzymology of one-carbon metabolism in methanogenic pathways","volume":"23","author":"Ferry","year":"1999","journal-title":"FEMS Microbiol. Rev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1016\/j.gca.2015.04.015","article-title":"Distinguishing and understanding thermogenic and biogenic sources of methane using multiply substituted isotopologues","volume":"161","author":"Stolper","year":"2015","journal-title":"Geochim. Et Cosmochim. Acta"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1036","DOI":"10.1002\/rcm.6549","article-title":"\u03b413C and \u03b42H measurement of methane from ecological and geological sources by gas chromatography\/ combustion\/ pyrolysis isotope-ratio mass spectrometry","volume":"27","author":"Yarnes","year":"2013","journal-title":"Rapid Commun. Mass Spectrom."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1707","DOI":"10.5194\/amt-3-1707-2010","article-title":"Continuous-flow isotope ratio mass spectrometry method for carbon and hydrogen isotope measurements on atmospheric methane","volume":"3","author":"Brass","year":"2010","journal-title":"Atmos. Meas. Tech."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1007\/s00340-007-2875-4","article-title":"Trace gas monitoring with infrared laser-based detection schemes","volume":"90","author":"Sigrist","year":"2008","journal-title":"Appl. Phys. B"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"A528","DOI":"10.1364\/OE.24.00A528","article-title":"Compact TDLAS based sensor design using interband cascade lasers for mid-IR trace gas sensing","volume":"24","author":"Dong","year":"2016","journal-title":"Opt. Express"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/S0009-2614(00)00107-X","article-title":"Ringdown and cavity-enhanced absorption spectroscopy using a continuous-wave tunable diode laser and a rapidly swept optical cavity","volume":"319","author":"He","year":"2000","journal-title":"Chem. Phys. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.cplett.2011.05.052","article-title":"Rapidly swept continuous-wave cavity-ringdown spectroscopy","volume":"512","author":"Orr","year":"2011","journal-title":"Chem. Phys. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"7704","DOI":"10.1364\/AO.33.007704","article-title":"High-precision direct measurements of 13CH4\/12CH4 and 12CH3D\/12CH4 ratios in atmospheric methane sources by means of a long-path tunable diode laser absorption spectrometer","volume":"33","author":"Bergamaschi","year":"1994","journal-title":"Appl. Opt."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1007\/s00340-010-3924-y","article-title":"Near infrared diode laser spectroscopy of C2H2, H2O, CO2 and their isotopologues and the application to TDLAS, a tunable diode laser spectrometer for the martian PHOBOS-GRUNT space mission","volume":"99","author":"Durry","year":"2010","journal-title":"Appl. Phys. B"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.infrared.2019.06.002","article-title":"Near infrared heterodyne radiometer for continuous measurements of atmospheric CO2 column concentration","volume":"101","author":"Deng","year":"2019","journal-title":"Infrared Phys. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Li, X., Yuan, F., Hu, M., Chen, B., He, Y., Yang, C., Shi, L., and Kan, R. (2020). Compact open-path sensor for fast measurements of CO2 and H2O using scanned-wavelength modulation spectroscopy with 1f-phase method. Sensors, 20.","DOI":"10.3390\/s20071910"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Berden, G., and Richard, E. (2009). Cavity Ring-Down Spectroscopy: Techniques and Applications, John Wiley & Sons.","DOI":"10.1002\/9781444308259"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"375","DOI":"10.5194\/amt-3-375-2010","article-title":"High-accuracy continuous airborne measurements of greenhouse gases (CO2 and CH4) using the cavity ring-down spectroscopy (CRDS) technique","volume":"3","author":"Chen","year":"2010","journal-title":"Atmos. Meas. Tech."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"083106","DOI":"10.1063\/5.0004742","article-title":"Development of an in situ analysis system for methane dissolved in seawater based on cavity ringdown spectroscopy","volume":"91","author":"Yuan","year":"2020","journal-title":"Rev. Sci. Instrum."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3867","DOI":"10.5194\/amt-8-3867-2015","article-title":"Comprehensive laboratory and field testing of cavity ring-down spectroscopy analyzers measuring H2O, CO2, CH4 and CO","volume":"8","author":"Laurent","year":"2015","journal-title":"Atmos. Meas. Tech."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"174302","DOI":"10.1063\/1.2723735","article-title":"Cavity ring-down spectroscopy measurements of single aerosol particle extinction. I. The effect of position of a particle within the laser beam on extinction","volume":"126","author":"Butler","year":"2007","journal-title":"J. Chem. Phys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3963","DOI":"10.1021\/jp810310b","article-title":"Optical-feedback cavity ring-down spectroscopy measurements of extinction by aerosol particles","volume":"113","author":"Butler","year":"2009","journal-title":"J. Phys. Chem. A"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"31850","DOI":"10.1364\/OE.27.031850","article-title":"Comb-assisted, Pound-Drever-Hall locked cavity ring-down spectrometer for high-performance retrieval of transition parameters","volume":"27","author":"Guo","year":"2019","journal-title":"Opt. Express"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/j.jqsrt.2015.03.031","article-title":"Frequency-agile, rapid scanning cavity ring-down spectroscopy (FARS-CRDS) measurements of the (30012)\u2190(00001) near-infrared carbon dioxide band","volume":"161","author":"Long","year":"2015","journal-title":"J. Quant. Spectrosc. Radiat. Transf."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2236","DOI":"10.1016\/j.jqsrt.2010.05.014","article-title":"High sensitivity CRDS of the a1\u0394g\u2212 X3\u03a3g\u2212 band of oxygen near 1.27 \u03bcm: Extended observations, quadrupole transitions, hot bands and minor isotopologues","volume":"111","author":"Leshchishina","year":"2010","journal-title":"J. Quant. Spectrosc. Radiat. Transf."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2003","DOI":"10.1021\/ac025511d","article-title":"Stable isotope ratios using cavity ring-down spectroscopy: Determination of 13C\/12C for carbon dioxide in human breath","volume":"74","author":"Crosson","year":"2002","journal-title":"Anal. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"8170","DOI":"10.3390\/s130708170","article-title":"Measurements of the weak UV absorptions of isoprene and acetone at 261\u2013275 nm using cavity ringdown spectroscopy for evaluation of a potential portable ringdown breath analyzer","volume":"13","author":"Sahay","year":"2013","journal-title":"Sensors"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"014002","DOI":"10.1088\/1752-7155\/1\/1\/014002","article-title":"Infrared laser spectroscopy for online recording of exhaled carbon monoxide\u2014A progress report","volume":"1","author":"Fritsch","year":"2007","journal-title":"J. Breath Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1007\/s003400000509","article-title":"Isotopic ratio measurement of methane in ambient air using mid-infrared cavity leak-out spectroscopy","volume":"72","author":"Dahnke","year":"2001","journal-title":"Appl. Phys. B"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"115701","DOI":"10.1088\/1612-202X\/aa8584","article-title":"Cavity ring-down spectroscopy using an EC-QCL operating at 7.5 \u00b5m for direct monitoring of methane isotopes in air","volume":"14","author":"Maity","year":"2017","journal-title":"Laser Phys. Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"11250","DOI":"10.1021\/ac401605s","article-title":"Measurement of the 13C\/12C of atmospheric CH4 using near-infrared (NIR) cavity ring-down spectroscopy","volume":"85","author":"Chen","year":"2013","journal-title":"Anal. Chem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"4539","DOI":"10.5194\/amt-8-4539-2015","article-title":"Local-and regional-scale measurements of CH4, \u03b413CH4, and C2H6 in the Uintah Basin using a mobile stable isotope analyzer","volume":"8","author":"Rella","year":"2015","journal-title":"Atmos. Meas. Tech."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"12938","DOI":"10.1021\/es4027776","article-title":"Novel use of cavity ring-down spectroscopy to investigate aquatic carbon cycling from microbial to ecosystem scales","volume":"47","author":"Maher","year":"2013","journal-title":"Environ. Sci. Technol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1016\/S0009-2614(98)01173-7","article-title":"Frequency-matched cavity ring-down spectroscopy","volume":"297","author":"Schulz","year":"1998","journal-title":"Chem. Phys. Lett."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1007\/s00340-002-0983-8","article-title":"Rapidly swept, continuous-wave cavity ringdown spectroscopy with optical heterodyne detection: Single- and multi-wavelength sensing of gases","volume":"75","author":"He","year":"2002","journal-title":"Appl. Phys. B"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1016\/S0009-2614(96)01351-6","article-title":"CW cavity ring down spectroscopy","volume":"264","author":"Romanini","year":"1997","journal-title":"Chem. Phys. Lett."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"234201","DOI":"10.1063\/1.4769974","article-title":"Cavity ring down spectroscopy with 5 \u00d7 10\u221213 cm\u22121 sensitivity","volume":"137","author":"Kassi","year":"2012","journal-title":"J. Chem. Phys."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"975","DOI":"10.1139\/p05-054","article-title":"An historical overview of cavity-enhanced methods","volume":"83","author":"Paldus","year":"2005","journal-title":"Can. J. Phys."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"7716","DOI":"10.1364\/AO.53.007716","article-title":"Ultrasensitive, self-calibrated cavity ring-down spectrometer for quantitative trace gas analysis","volume":"53","author":"Chen","year":"2014","journal-title":"Appl. Opt."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"20059","DOI":"10.1364\/OE.18.020059","article-title":"Simultaneous multi-laser, multi-species trace-level sensing of gas mixtures by rapidly swept continuous-wave cavity-ringdown spectroscopy","volume":"18","author":"He","year":"2010","journal-title":"Opt. Express"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1007\/s00340-008-3137-9","article-title":"Design considerations in high-sensitivity off-axis integrated cavity output spectroscopy","volume":"92","author":"Moyer","year":"2008","journal-title":"Appl. Phys. B"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1378","DOI":"10.1364\/AO.49.001378","article-title":"Long-term stability in continuous wave cavity ringdown spectroscopy experiments","volume":"49","author":"Huang","year":"2010","journal-title":"Appl. Opt."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1007\/BF00425997","article-title":"The limits of signal averaging in atmospheric trace-gas monitoring by tunable diode-laser absorption spectroscopy (TDLAS)","volume":"57","author":"Werle","year":"1993","journal-title":"Appl. Phys. B"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"19074","DOI":"10.1364\/OE.393292","article-title":"Light-induced thermo-elastic effect in quartz tuning forks exploited as a photodetector in gas absorption spectroscopy","volume":"28","author":"Russo","year":"2020","journal-title":"Opt. Express"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"25100","DOI":"10.1364\/OE.434128","article-title":"Ppt level carbon monoxide detection based on light-induced thermoelastic spectroscopy exploring custom quartz tuning forks and a mid-infrared QCL","volume":"29","author":"Qiao","year":"2021","journal-title":"Opt. Express"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/22\/7622\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:31:22Z","timestamp":1760167882000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/22\/7622"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,11,17]]},"references-count":44,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2021,11]]}},"alternative-id":["s21227622"],"URL":"https:\/\/doi.org\/10.3390\/s21227622","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,11,17]]}}}