{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T19:49:42Z","timestamp":1790711382432,"version":"4.1.0"},"reference-count":32,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2012,11,28]],"date-time":"2012-11-28T00:00:00Z","timestamp":1354060800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper we present a prototype instrument for remote open-path detection of nitrous oxide. The sensor is based on a 4.53 \u03bcm quantum cascade laser and uses the chirped laser dispersion spectroscopy (CLaDS) technique for molecular concentration measurements. To the best of our knowledge this is the first demonstration of open-path laser-based trace-gas detection using a molecular dispersion measurement. The prototype sensor achieves a detection limit down to the single-ppbv level and exhibits excellent stability and robustness. The instrument characterization, field deployment performance, and the advantages of applying dispersion sensing to sensitive trace-gas detection in a remote open-path configuration are presented.<\/jats:p>","DOI":"10.3390\/s121216466","type":"journal-article","created":{"date-parts":[[2012,11,28]],"date-time":"2012-11-28T11:03:39Z","timestamp":1354100619000},"page":"16466-16481","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":81,"title":["Chirped Laser Dispersion Spectroscopy for Remote Open-Path Trace-Gas Sensing"],"prefix":"10.3390","volume":"12","author":[{"given":"Michal","family":"Nikodem","sequence":"first","affiliation":[{"name":"Electrical Engineering Department, Princeton University, Princeton, NJ 08540, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gerard","family":"Wysocki","sequence":"additional","affiliation":[{"name":"Electrical Engineering Department, Princeton University, Princeton, NJ 08540, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2012,11,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1007\/s00340-005-2010-3","article-title":"Open-path ozone detection by quantum-cascade laser","volume":"82","author":"Taslakov","year":"2005","journal-title":"Appl. Phys. B"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"12587","DOI":"10.1073\/pnas.0906291106","article-title":"Ultrasensitive detection of nitric oxide at 5.33 \u03bcm by using external cavity quantum cascade laser-based Faraday rotation spectroscopy","volume":"106","author":"Lewicki","year":"2009","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"McCurdy, M.R., Bakhirkin, Y., Wysocki, G., Lewicki, R., and Tittel, F.K. (2007). Recent advances of laser-spectroscopy-based techniques for applications in breath analysis. J. Breath Res., 1.","DOI":"10.1088\/1752-7155\/1\/1\/014001"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Lewicki, R., Kosterev, A.A., Thomazy, D.M., Risby, T.H., Solga, S., Schwartz, T.B., and Tittel, F.K. (2011). Real time ammonia detection in exhaled human breath using a distributed feedback quantum cascade laser based sensor. Proc. SPIE.","DOI":"10.1117\/12.874887"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Rayner, T., Weida, M., Pushkarsky, M., and Day, T. (2007). Remote explosive and chemical agent detection using broadly tunable mid-infrared external cavity quantum cascade lasers. Proc. SPIE.","DOI":"10.1117\/12.727700"},{"key":"ref_6","unstructured":"Radziemski, L.J., Solarz, R.W., and Paisner, J.A. (1987). Laser Spectroscopy and Its Applications, Marcel Dekker, Inc."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/S0925-4005(03)00102-3","article-title":"Precise isotope abundance ratio measurement of nitrous oxide using diode lasers","volume":"90","author":"Uehara","year":"2003","journal-title":"Sens. Actuators B Chem"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"5546","DOI":"10.1364\/AO.48.005546","article-title":"Calibration-free wavelength-modulation spectroscopy for measurements of gas temperature and concentration in harsh environments","volume":"48","author":"Rieker","year":"2009","journal-title":"Appl. Opt"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"26123","DOI":"10.1364\/OE.18.026123","article-title":"Molecular dispersion spectroscopy for chemical sensing using chirped mid-infrared quantum cascade laser","volume":"18","author":"Wysocki","year":"2010","journal-title":"Optic. Express"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1098\/rspl.1901.0096","article-title":"The anomalous dispersion of sodium vapour","volume":"69","author":"Wood","year":"1902","journal-title":"Proc. Roy. Soc. London"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"795","DOI":"10.1109\/JQE.1980.1070570","article-title":"Measurements of the anomalous dispersion of HF in absorption","volume":"16","author":"Gross","year":"1980","journal-title":"IEEE J. Quant. Electron"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.optcom.2005.01.057","article-title":"Measurement of the refractive index dispersion around an absorbing line","volume":"249","author":"Marchetti","year":"2005","journal-title":"Opt. Commun"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1007\/s00340-010-4120-9","article-title":"Highly sensitive dispersion spectroscopy by probing the free spectral range of an optical cavity using dual-frequency modulation","volume":"101","author":"Schmidt","year":"2010","journal-title":"Appl. Phys. B"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1111\/j.1749-6632.2012.06660.x","article-title":"Molecular dispersion spectroscopy\u2014New capabilities in laser chemical sensing","volume":"1260","author":"Nikodem","year":"2012","journal-title":"Ann. N. Y. Acad. Sci"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Franz, K., Weidmann, D., and Wysocki, G. (2010, January 16\u201321). High Dynamic Range Laser Dispersion Spectroscopy of Saturated Absorption Lines. San Jose, CA, USA.","DOI":"10.1364\/CLEO.2010.CMJ4"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1165","DOI":"10.1364\/AO.21.001165","article-title":"Model studies of laser absorption computed tomography for remote air pollution measurement","volume":"21","author":"Wolfe","year":"1982","journal-title":"Appl. Opt"},{"key":"ref_17","unstructured":"Varma, R., Hashmonay, R., Kagann, R., and Bolch, A. (2005). Optical Remote Sensing to Determine Strength of Nonpoint Sources: Duke Forest Validation Study, Final Technical Report for ARCADIS Geraghty and Miller, Inc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1364\/OE.20.000644","article-title":"Signal-to-noise ratio in chirped laser dispersion spectroscopy","volume":"20","author":"Nikodem","year":"2012","journal-title":"Opt. Express"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Nikodem, M., Weidmann, D., and Wysocki, G. (2012). Chirped laser dispersion spectroscopy with harmonic detection of molecular spectra. Appl. Phys. B.","DOI":"10.1364\/E2.2012.EM2D.2"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1007\/s00340-002-0962-0","article-title":"Digital, phasesensitive detection for in situ diode-laser spectroscopy under rapidly changing transmission conditions","volume":"75","author":"Fernholz","year":"2002","journal-title":"Appl. Phys. B"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"5803","DOI":"10.1364\/AO.38.005803","article-title":"Theoretical description based on Fourier analysis of wavelength-modulation spectrometry in terms of analytical and background signals","volume":"38","author":"Kluczynski","year":"1999","journal-title":"Appl. Opt"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"6740","DOI":"10.1364\/AO.48.006740","article-title":"Measurements of CO2 concentration and temperature at high pressures using 1f-normalized wavelength modulation spectroscopy with second harmonic detection near 2.7 \u03bcm","volume":"48","author":"Farooq","year":"2009","journal-title":"Appl. Opt"},{"key":"ref_23","unstructured":"Methane and Nitrous Oxide Emissions From Natural Sources. Available online: http:\/\/www.epa.gov\/nitrousoxide\/sources.html (acessed on 23 November 2012)."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2921","DOI":"10.1029\/95GL02822","article-title":"Increase in the atmospheric nitrous oxide concentration during last 250 years","volume":"22","author":"Machida","year":"1995","journal-title":"Geophys. Res. Lett"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1111\/j.1600-0889.2008.00406.x","article-title":"Variations of atmospheric nitrous oxide concentration in the northern and western Pacific","volume":"61","author":"Ishijima","year":"2009","journal-title":"Tellus B"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3325","DOI":"10.1016\/j.saa.2004.01.033","article-title":"High precision measurements of atmospheric nitrous oxide and methane using thermoelectrically cooled mid-infrared quantum cascade lasers and detectors","volume":"60","author":"Nelson","year":"2004","journal-title":"Spectrochim. Acta A Mol. Biomol. Spectros"},{"key":"ref_27","unstructured":"Tao, L., Sun, K., Khan, M.A., Miller, D.J., and Zondlo, M.A. (February, January 29). Simultaneous Open-Path Detection of Atmospheric N2O and CO. San Diego, CA, USA."},{"key":"ref_28","unstructured":"Carlson, A.B., and Crilly, P.B. (2010). Communication Systems. An Introduction to Signal and Noise in Electrical Communication, McGraw-Hill Higher Education. [5th ed]."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1016\/j.agrformet.2009.07.013","article-title":"N2O exchange over managed grassland: Application of a quantum cascade laser spectrometer for micrometeorological flux measurements","volume":"150","author":"Neftel","year":"2010","journal-title":"Agric. For. Meteorol"},{"key":"ref_30","first-page":"2057","article-title":"Impact of extreme precipitation and water table change on N2O fluxes in a bio-energy poplar plantation","volume":"8","author":"Zona","year":"2011","journal-title":"Biogeosci. Discuss"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Khan, A., Sun, K., Miller, D., and Zondlo, M. (2011). Simultaneous detection of atmospheric nitrous oxide and carbon monoxide using a quantum cascade laser. Proc. SPIE.","DOI":"10.1117\/12.884275"},{"key":"ref_32","unstructured":"Zondlo, M., and Wysocki, G. (2012). Private communication, Princeton, NJ, USA,."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/12\/12\/16466\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:53:53Z","timestamp":1760219633000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/12\/12\/16466"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012,11,28]]},"references-count":32,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2012,12]]}},"alternative-id":["s121216466"],"URL":"https:\/\/doi.org\/10.3390\/s121216466","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012,11,28]]}}}