CW EC-QCL-based sensor for simultaneous detection of H2O, HDO, N2O and CH4 using multi-pass absorption spectroscopy

A sensor system based on a continuous wave, external-cavity quantum-cascade laser (CW EC-QCL) was demonstrated for simultaneous detection of atmospheric H2O, HDO, N2O and CH4 using a compact, dense pattern multi-pass gas cell with an effective path-length of 57.6 m. The ECQCL with a mode-hop-free spectral range of 1225-1285 cm operating at ~7.8 μm was scanned covering four neighboring absorption lines, for H2O at 1281.161 cm, HDO at 1281.455 cm, N2O at 1281.53 cm and CH4 at 1281.61 cm. A first-harmonic-normalized wavelength modulation spectroscopy with second-harmonic detection (WMS-2f/1f) strategy was employed for data processing. An Allan-Werle deviation analysis indicated that minimum detection limits of 1.77 ppmv for H2O, 3.92 ppbv for HDO, 1.43 ppbv for N2O, and 2.2 ppbv for CH4 were achieved with integration times of 50-s, 50-s, 100-s and 129-s, respectively. Experimental measurements of ambient air are also reported. ©2016 Optical Society of America OCIS codes: (280.3420) Laser sensors; (010.1280) Atmospheric composition; (300.6340) Spectroscopy, infrared; (140.5965) Semiconductor lasers, quantum cascade. References and links 1. R. K. Pachauri, M. Allen, V. Barros, J. Broome, W. Cramer, R. Christ, J. Church, L. Clarke, Q. Dahe, and P. Dasgupta, “Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change” (2014). 2. Y. Cao, N. P. Sanchez, W. Jiang, R. J. Griffin, F. Xie, L. C. Hughes, C. E. Zah, and F. K. Tittel, “Simultaneous atmospheric nitrous oxide, methane and water vapor detection with a single continuous wave quantum cascade laser,” Opt. Express 23(3), 2121–2132 (2015). 3. D. Noone, “Pairing measurements of the water vapor isotope ratio with humidity to deduce atmospheric moistening and dehydration in the tropical midtroposphere,” J. Clim. 25(13), 4476–4494 (2012). 4. S. A. Montzka, E. J. Dlugokencky, and J. H. Butler, “Non-CO2 greenhouse gases and climate change,” Nature 476(7358), 43–50 (2011). 5. A. A. Kosterev, R. F. Curl, F. K. Tittel, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, A. L. Hutchinson, and A. Y. Cho, “Effective utilization of quantum-cascade distributed-feedback lasers in absorption spectroscopy,” Appl. Opt. 39(24), 4425–4430 (2000). 6. D. D. Nelson, B. McManus, S. Urbanski, S. Herndon, and M. S. Zahniser, “High precision measurements of atmospheric nitrous oxide and methane using thermoelectrically cooled mid-infrared quantum cascade lasers and detectors,” Spectrochim. Acta A Mol. Biomol. Spectrosc. 60(14), 3325–3335 (2004). 7. M. Jahjah, W. Ren, P. Stefański, R. Lewicki, J. Zhang, W. Jiang, J. Tarka, and F. K. Tittel, “A compact QCL based methane and nitrous oxide sensor for environmental and medical applications,” Analyst (Lond.) 139(9), 2065–2069 (2014). 8. G. Hancock, J. Van Helden, R. Peverall, G. Ritchie, and R. Walker, “Direct and wavelength modulation spectroscopy using a cw external cavity quantum cascade laser,” Appl. Phys. Lett. 94(20), 201110 (2009). 9. J. Li, U. Parchatka, and H. Fischer, “A formaldehyde trace gas sensor based on a thermoelectrically cooled CWDFB quantum cascade laser,” Anal. Methods 6(15), 5483–5488 (2014). 10. W. Ren, W. Jiang, and F. K. Tittel, “Single-QCL-based absorption sensor for simultaneous trace-gas detection of CH4 and N2O,” Appl. Phys. B 117(1), 245–251 (2014). #262458 Received 4 Apr 2016; accepted 29 Apr 2016; published 3 May 2016 © 2016 OSA 16 May 2016 | Vol. 24, No. 10 | DOI:10.1364/OE.24.010391 | OPTICS EXPRESS 10391 11. Y. Cao, N. P. Sanchez, W. Jiang, W. Ren, R. Lewicki, D. Jiang, and R. J. Griffin, “Multi-pass absorption spectroscopy for H2O2 detection using a CW DFB-QCL,” Adv. Opt. Technol. 3, 549–558 (2014). 12. G. Wysocki, R. F. Curl, F. K. Tittel, R. Maulini, J.-M. Bulliard, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade laser for high resolution spectroscopic applications,” Appl. Phys. B 81(6), 769– 777 (2005). 13. G. Wysocki, R. Lewicki, R. Curl, F. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B 92(3), 305–311 (2008). 14. X. Chao, J. Jeffries, and R. Hanson, “Wavelength-modulation-spectroscopy for real-time, in situ NO detection in combustion gases with a 5.2 μm quantum-cascade laser,” Appl. Phys. B 106(4), 987–997 (2012). 15. K. Krzempek, M. Jahjah, R. Lewicki, P. Stefański, S. So, D. Thomazy, and F. K. Tittel, “CW DFB RT diode laser-based sensor for trace-gas detection of ethane using a novel compact multipass gas absorption cell,” Appl. Phys. B 112(4), 461–465 (2013). 16. L. Dong, Y. Yu, C. Li, S. So, and F. K. Tittel, “Ppb-level formaldehyde detection using a CW room-temperature interband cascade laser and a miniature dense pattern multipass gas cell,” Opt. Express 23(15), 19821–19830 (2015). 17. H. Li, A. Farooq, J. Jeffries, and R. Hanson, “Near-infrared diode laser absorption sensor for rapid measurements of temperature and water vapor in a shock tube,” Appl. Phys. B 89(2-3), 407–416 (2007). 18. L. Rothman, I. Gordon, Y. Babikov, A. Barbe, D. C. Benner, P. Bernath, M. Birk, L. Bizzocchi, V. Boudon, and L. Brown, “The HITRAN2012 molecular spectroscopic database,” J. Quant. Spectrosc. Radiat. Transf. 130, 4– 50 (2013). 19. X. Liu, X. Zhou, A. Feitisch, and G. Sanger, “Pressure-invariant trace gas detection,” U.S. Patent No. 7,508,521 (2009). 20. H. Li, G. B. Rieker, X. Liu, J. B. Jeffries, and R. K. Hanson, “Extension of wavelength-modulation spectroscopy to large modulation depth for diode laser absorption measurements in high-pressure gases,” Appl. Opt. 45(5), 1052–1061 (2006). 21. G. B. Rieker, J. B. Jeffries, and R. K. Hanson, “Calibration-free wavelength-modulation spectroscopy for measurements of gas temperature and concentration in harsh environments,” Appl. Opt. 48(29), 5546–5560 (2009). 22. D. Rehle, D. Leleux, M. Erdelyi, F. Tittel, M. Fraser, and S. Friedfeld, “Ambient formaldehyde detection with a laser spectrometer based on difference-frequency generation in PPLN,” Appl. Phys. B 72(8), 947–952 (2001). 23. M. Schneider, F. Hase, and T. Blumenstock, “Ground-based remote sensing of HDO/H2O ratio profiles: introduction and validation of an innovative retrieval approach,” Atmos. Chem. Phys. 6(12), 4705–4722 (2006). 24. S. Kirschke, P. Bousquet, P. Ciais, M. Saunois, J. G. Canadell, E. J. Dlugokencky, P. Bergamaschi, D. Bergmann, D. R. Blake, L. Bruhwiler, P. Cameron-Smith, S. Castaldi, F. Chevallier, L. Feng, A. Fraser, M. Heimann, E. L. Hodson, S. Houweling, B. Josse, P. J. Fraser, P. B. Krummel, J.-F. Lamarque, R. L. Langenfelds, C. Le Quéré, V. Naik, S. O’Doherty, P. I. Palmer, I. Pison, D. Plummer, B. Poulter, R. G. Prinn, M. Rigby, B. Ringeval, M. Santini, M. Schmidt, D. T. Shindell, I. J. Simpson, R. Spahni, L. P. Steele, S. A. Strode, K. Sudo, S. Szopa, G. R. van der Werf, A. Voulgarakis, M. van Weele, R. F. Weiss, J. E. Williams, and G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013). 25. I. Bamberger, J. Stieger, N. Buchmann, and W. Eugster, “Spatial variability of methane: attributing atmospheric concentrations to emissions,” Environ. Pollut. 190, 65–74 (2014). 26. L. Dong, C. Li, N. P. Sanchez, A. K. Gluszek, R. J. Griffin, and F. K. Tittel, “Compact CH4 sensor system based on a continuous-wave, low power consumption, room temperature interband cascade laser,” Appl. Phys. Lett. 108(1), 011106 (2016).