Abstract

A continuous-wave, rapidly swept cavity-ringdown spectroscopic technique has been developed for localized atmospheric sensing of trace gases at remote sites. It uses one or more passive open-path optical sensor units, coupled by optical fiber over distances of >1 km to a single transmitter/receiver console incorporating a photodetector and a swept-frequency diode laser tuned to molecule-specific near-infrared wavelengths. Ways to avoid interference from stimulated Brillouin scattering in long optical fibers have been devised. This rugged open-path system, deployable in agricultural, industrial, and natural atmospheric environments, is used to monitor ammonia in air. A noise-limited minimum detectable mixing ratio of ~11 ppbv is attained for ammonia in nitrogen at atmospheric pressure.

© 2014 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. K. W. Busch and M. A. Busch, eds., Cavity-Ringdown Spectroscopy: an Ultratrace-Absorption Measurement Technique, Vol. 720 of ACS Symposium Series (Am. Chem. Soc., 1999).
  2. G. Berden, R. Peeters, G. Meijer, “Cavity ring-down spectroscopy: experimental schemes and applications,” Int. Rev. Phys. Chem. 19(4), 565–607 (2000).
    [CrossRef]
  3. B. A. Paldus, A. A. Kachanov, “An historical overview of cavity-enhanced methods,” Can. J. Phys. 83(10), 975–999 (2005).
    [CrossRef]
  4. G. Berden and R. Engeln, eds., Cavity Ring-Down Spectroscopy: Techniques and Applications (Wiley-Blackwell, 2009).
  5. B. J. Orr, Y. He, “Rapidly swept continuous-wave cavity-ringdown spectroscopy,” Chem. Phys. Lett. 512(1-3), 1–20 (2011).
    [CrossRef]
  6. Y. He, B. J. Orr, “Detection of trace gases by rapidly-swept continuous-wave cavity ringdown spectroscopy: pushing the limits of sensitivity,” Appl. Phys. B 85(2-3), 355–364 (2006).
    [CrossRef]
  7. Y. He, B. J. Orr, “Rapidly swept, continuous-wave cavity ringdown spectroscopy with optical heterodyne detection: single- and multi-wavelength sensing of gases,” Appl. Phys. B 75(2-3), 267–280 (2002).
    [CrossRef]
  8. Y. He, R. Kan, F. V. Englich, W. Liu, B. J. Orr, “Simultaneous multi-laser, multi-species trace-level sensing of gas mixtures by rapidly swept continuous-wave cavity-ringdown spectroscopy,” Opt. Express 18(19), 20059–20071 (2010).
    [CrossRef] [PubMed]
  9. Y. He, B. J. Orr, “Rapid measurement of cavity ringdown absorption spectra with a swept-frequency laser,” Appl. Phys. B 79(8), 941–945 (2004).
    [CrossRef]
  10. Y. He, B. J. Orr, “Continuous-wave cavity ringdown absorption spectroscopy with a swept-frequency laser: rapid spectral sensing of gas-phase molecules,” Appl. Opt. 44(31), 6752–6761 (2005).
    [CrossRef] [PubMed]
  11. I. T. Sorokina and K. L. Vodopyanov, eds., Solid-State Mid-Infrared Sources (Springer, 2003).
  12. F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
    [CrossRef]
  13. R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
    [CrossRef]
  14. M. S. Taubman, P. M. Aker, D. C. Scott, M. D. Wojcik, B. D. Cannon, J. T. Munley, T. L. Myers, V. T. Nguyen, C. A. Bonebrake, and J. F. Schultz, “Long wave infrared cavity enhanced sensors,” Pacific Northwest National Laboratory Report PNNL-15103 (October 2004), Fig. 2.1, p. 2.2. http://www.pnl.gov/main/publications/external/technical_reports/PNNL-15103.pdf
  15. Y. He, B. J. Orr, “Optical heterodyne signal generation and detection in cavity ringdown spectroscopy based on a rapidly swept cavity,” Chem. Phys. Lett. 335(3-4), 215–220 (2001).
    [CrossRef]
  16. J. Ye, “Ultrasensitive high resolution laser spectroscopy and its application to optical frequency standards,” Ph. D. thesis (University of Colorado, 1997); note Fig. 6.2, p. 121.
  17. J. Ye, L.-S. Ma, and J. L. Hall, “Using FM methods with molecules in a high finesse cavity: a demonstrated path to 10−12 absorption sensitivity,” Chap. 15 in K. W. Busch and M. A. Busch, eds., Cavity-Ringdown Spectroscopy: an Ultratrace-Absorption Measurement Technique, Vol. 720 of ACS Symposium Series (Am. Chem. Soc., 1999), pp. 233–253; note Fig. 3, p. 241.
  18. M. D. Levenson, B. A. Paldus, T. G. Spence, C. C. Harb, R. N. Zare, M. J. Lawrence, R. L. Byer, “Frequency-switched heterodyne cavity ringdown spectroscopy,” Opt. Lett. 25(12), 920–922 (2000).
    [CrossRef] [PubMed]
  19. Y. He, B. J. Orr, “Ringdown and cavity-enhanced absorption spectroscopy using a continuous-wave tunable diode laser and a rapidly swept optical cavity,” Chem. Phys. Lett. 319(1-2), 131–137 (2000).
    [CrossRef]
  20. J. Poirson, F. Bretenaker, M. Vallet, A. Le Floch, “Analytical and experimental study of ringing effects in a Fabry–Perot cavity. Application to the measurement of high finesses,” J. Opt. Soc. Am. B 14(11), 2811–2817 (1997).
    [CrossRef]
  21. M. J. Lawrence, B. Wilke, M. E. Husman, E. K. Gustafson, R. L. Byer, “Dynamic response of a Fabry–Perot interferometer,” J. Opt. Soc. Am. B 16(4), 523–532 (1999).
    [CrossRef]
  22. J. W. Hahn, Y. S. Yoo, J. Y. Lee, J. W. Kim, H.-W. Lee, “Cavity ringdown spectroscopy with a continuous-wave laser: calculation of coupling efficiency and a new spectrometer design,” Appl. Opt. 38(9), 1859–1866 (1999).
    [CrossRef] [PubMed]
  23. J. Morville, D. Romanini, M. Chenevier, A. Kachanov, “Effects of laser phase noise on the injection of a high-finesse cavity,” Appl. Opt. 41(33), 6980–6990 (2002).
    [CrossRef] [PubMed]
  24. B. Bakowski, L. Corner, G. Hancock, R. Kotchie, R. Peverall, G. A. D. Ritchie, “Cavity-enhanced absorption spectroscopy with a rapidly swept diode laser,” Appl. Phys. B 75(6-7), 745–750 (2002).
    [CrossRef]
  25. M. Mazurenka, A. J. Orr-Ewing, R. R. Peverall, G. A. D. Ritchie, “Cavity ring-down and cavity enhanced spectroscopy using diode lasers,” Ann. Rep. Prog. Chem. C: Phys. Chem. 101, 100–142 (2005).
    [CrossRef]
  26. J. H. van Helden, R. Peverall, and G. A. D. Ritchie, “Cavity enhanced techniques using continuous wave lasers,” Chap. 2 in G. Berden and R. Engeln, eds., Cavity Ring-Down Spectroscopy: Techniques and Applications (Wiley-Blackwell, 2009), pp. 27–56.
  27. T. G. Spence, C. C. Harb, B. A. Paldus, R. N. Zare, B. Willke, R. L. Byer, “A laser-locked cavity ring-down spectrometer employing an analog detection scheme,” Rev. Sci. Instrum. 71(2), 347–353 (2000).
    [CrossRef]
  28. B. G. Fidric, R. A. Provençal, S. M. Tan, E. R. Crosson, A. A. Kachanov, B. A. Paldus, “Bananas, explosives and the future of cavity ring-down spectroscopy,” Opt. Photon. News 14(7), 24–29 (2003).
    [CrossRef]
  29. E. R. Crosson, “A cavity ring-down analyzer for measuring atmospheric levels of methane, carbon dioxide, and water vapor,” Appl. Phys. B 92(3), 403–408 (2008).
    [CrossRef]
  30. For example: Picarro, Inc., (Sunnyvale, CA 94085, USA); http://www.picarro.com/gas_analyzers
  31. G. Neri, A. Lacquaniti, G. Rizzo, N. Donato, M. Latino, M. Buemi, “Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques,” Nephrol. Dial. Transplant. 27(7), 2945–2952 (2012).
    [CrossRef] [PubMed]
  32. F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
    [CrossRef] [PubMed]
  33. O. Vaittinen, F. M. Schmidt, M. Metsälä, L. Halonen, “Exhaled breath biomonitoring using laser spectroscopy,” Current Analyt. Chem. 9(3), 463–475 (2013).
    [CrossRef]
  34. A. B. Ruffin, “Stimulated Brillouin scattering: an overview of measurements, system impairments, and applications,” in P. A. Williams and G. W. Day, eds., Technical Digest: Symposium on Optical Fiber Measurements,2004, NIST Special Publication 1024 (National Institute of Standards and Technology, 2004), pp. 23–28; http://www.nist.gov/manuscript-publication-search.cfm?pub_id=31763
  35. B. L. Fawcett, A. M. Parkes, D. E. Shallcross, A. J. Orr-Ewing, “Trace detection of methane using continuous wave cavity ring-down spectroscopy at 1.65 μm,” Phys. Chem. Chem. Phys. 4(24), 5960–5965 (2002).
    [CrossRef]
  36. R. Kan, W. Liu, Y. Zhang, J. Liu, M. Wang, D. Chen, J. Chen, Y. Cui, “Large scale gas leakage monitoring with tunable diode laser absorption spectroscopy,” Chin. Opt. Lett. 4, 116–118 (2006).
  37. R. Kan, W. Liu, Y. Zhang, J. Liu, M. Wang, D. Chen, J. Chen, Y. Cui, “A high sensitivity spectrometer with tunable diode laser for ambient methane monitoring,” Chin. Opt. Lett. 5, 54–57 (2007).
  38. C. Wang, N. Srivastava, B. A. Jones, R. B. Reese, “A novel multiple species ringdown spectrometer for in situ measurements of methane, carbon dioxide, and carbon isotope,” Appl. Phys. B 92(2), 259–270 (2008).
    [CrossRef]
  39. L. S. Rothman, I. E. Gordon, Y. Babikov, A. Barbe, D. C. Benner, P. F. Bernath, M. Birk, L. Bizzocchi, V. Boudon, L. R. Brown, A. Campargue, K. Chance, E. A. Cohen, L .H. Coudert, V. M. Devi, B. J. Drouin, A. Fayt, J.-M. Flaud, R. R. Gamache, J. J. Harrison, J.-M. Hartmann, C. Hill, J. T. Hodges, D. Jacquemart, A. Jolly, J. Lamouroux, R. J. Le Roy, G. Li, D. A. Long, O. M. Lyulin, C. J. Mackie, S. T. Massie, S. Mikhailenko, H. S. P. Müller, O. V. Naumenko, A. V. Nikitin, J. Orphal, V. Perevalov, A. Perrin, E. R. Polovtseva, C. Richard, M. A. H. Smith, E. Starikova, K. Sung, S. Tashkun, J. Tennyson, G. C. Toon, Vl. G. Tyuterev, and G. Wagner, “The HITRAN2012 molecular spectroscopic database,” J. Quant. Spectrosc. Radiat. Transfer 130, 4–50 (2013); see also earlier editions of the HITRAN database (e.g., 2008 and 2004).
  40. 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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
    [CrossRef]
  41. The CSIRO Flagship Livestock Methane Research Cluster (LMRC) is outlined at http://www.csiro.au/lmrc
  42. D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
    [CrossRef]
  43. M. A. Sutton, J. W. Erisman, F. Dentener, D. Möller, “Ammonia in the environment: from ancient times to the present,” Environ. Pollut. 156(3), 583–604 (2008).
    [CrossRef] [PubMed]
  44. C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
    [CrossRef]
  45. O. T. Denmead, D. Chen, D. Rowell, Z. Loh, J. Hill, S. Muir, D. W. T. Griffith, T. Naylor, M. Bai, F. Phillips, and S. McGinn, “Gaseous nitrogen emissions from Australian cattle feedlots,” Chapter 3 in M. A Sutton, K. E. Mason, L. J. Sheppard, H. Sverdrup, R. Haeuber, and W. K. Hicks, eds., Nitrogen Deposition, Critical Loads and Biodiversity (Springer, 2013); ISBN 978–94–007–7938–9.
  46. B. Arnon, N. Hutchings, F. P. Vinther, P. K. Nielsem, H. D. Poulsen, I. S. Kristensen, and S. Pietrzak, “Analysis of methodologies for calculating greenhouse gas and ammonia emissions and nutrient balances,” in J. Selenius, L. Baudouin, and A. M. Kremer, eds., Eurostat Methodologies and Working Papers; ISSN 1977–0375 (European Union, 2011).
    [CrossRef]
  47. K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
    [CrossRef]
  48. A. A. Kachanov, E. R. Crosson, B. A. Paldus, “Tunable diode lasers: expanding the horizon for laser absorption spectroscopy,” Opt. Photonics News 16(7), 44–50 (2005).
    [CrossRef]
  49. E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
    [CrossRef] [PubMed]
  50. Y. He, Y. Zhang, W. Liu, R. Kan, and H. Xia, “Atmospheric ammonia monitoring near Beijing National Stadium from July to October in 2008 by open-path TDLAS system,” in F. Amzajerdian, C-Q. Gao, T.-Y. Xie, eds., International Symposium on Photoelectronic Detection and Imaging 2009: Pt. 1 – Laser Sensing and Imaging, Proc. SPIE 7382, 73821L/1–73821L/7 (2009).
  51. Y. He, Y. Zhang, L. Wang, K. You, Y. Gao, A. Zhu, and W. Yang, “An ammonia sensor with high sensitivity in farmland based on laser absorption spectroscopy technology,” in B. Culshaw, ed., Advanced Sensor Systems and Applications V, Proc. SPIE 8561, 85610X/1–8 5610X/7 (2012).
  52. R. Peeters, G. Berden, A. Apituley, G. Meijer, “Open-path trace gas detection of ammonia based on cavity-enhanced absorption spectroscopy,” Appl. Phys. B 71(2), 231–236 (2000).
    [CrossRef]
  53. M. C. Phillips, M. S. Taubman, B. E. Bernacki, B. D. Cannon, J. T. Schiffern, and T. L. Myers, “Design and performance of a sensor system for detection of multiple chemicals using an external cavity quantum cascade laser,” in M. Razeghi, R. Sudharsanan, and G. J. Brown, eds., Quantum Sensing and Nanophotonic Devices VII, Proc. SPIE 7608, 76080D/1–76080D/11 (2010).
  54. D. J. Miller, K. Sun, L. Tao, M. A. Khan, and M. A. Zondlo, “Open-path, quantum cascade laser-based sensor for high resolution atmospheric ammonia measurements,” Atmos. Meas. Tech. Discuss. 6, 7005–7039 (2013); http://www.atmos-meas-tech-discuss.net/6/7005/2013/
    [CrossRef]
  55. L. Lundsberg-Nielsen, F. Hegelund, F. M. Nicolaisen, “Analysis of the high-resolution spectrum of ammonia (14NH3) in the near-infrared region, 6400–6900 cm–1,” J. Mol. Spectrosc. 162(1), 230–245 (1993).
    [CrossRef]
  56. M. E. Webber, D. S. Baer, R. K. Hanson, “Ammonia monitoring near 1.5 µm with diode-laser absorption sensors,” Appl. Opt. 40(12), 2031–2042 (2001).
    [CrossRef] [PubMed]
  57. C. L. Bell, M. Dhib, G. Hancock, G. A. D. Ritchie, J. H. van Helden, N. J. van Leeuwen, “Cavity enhanced absorption spectroscopy measurements of pressure-induced broadening and shift coefficients in the υ1 + υ3 combination band of ammonia,” Appl. Phys. B 94(2), 327–336 (2009).
    [CrossRef]
  58. B. A. Paldus, C. C. Harb, T. G. Spence, R. N. Zare, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, A. L. Hutchinson, A. Y. Cho, “Cavity ringdown spectroscopy using mid-infrared quantum-cascade lasers,” Opt. Lett. 25(9), 666–668 (2000).
    [CrossRef] [PubMed]
  59. Note in particular Picarro’s G2103 and G1103 near-IR WS-CRDS (Wavelength-Scanned Cavity Ring Down Spectroscopy) NH3 analyzers; see https://picarro.app.box.com/shared/ffey0e0mo8 and http://www.picarro.com/assets/docs/NH3_analyzer_datasheet.pdf , respectively.
  60. G. Burba and D. Anderson, A Brief Practical Guide to Eddy Covariance Flux Measurements (Li-COR Biosciences, 2010); http://www.licor.com/env/products/eddy_covariance/ec_book.html

2013 (4)

F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
[CrossRef] [PubMed]

O. Vaittinen, F. M. Schmidt, M. Metsälä, L. Halonen, “Exhaled breath biomonitoring using laser spectroscopy,” Current Analyt. Chem. 9(3), 463–475 (2013).
[CrossRef]

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

2012 (1)

G. Neri, A. Lacquaniti, G. Rizzo, N. Donato, M. Latino, M. Buemi, “Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques,” Nephrol. Dial. Transplant. 27(7), 2945–2952 (2012).
[CrossRef] [PubMed]

2011 (2)

B. J. Orr, Y. He, “Rapidly swept continuous-wave cavity-ringdown spectroscopy,” Chem. Phys. Lett. 512(1-3), 1–20 (2011).
[CrossRef]

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

2010 (3)

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

Y. He, R. Kan, F. V. Englich, W. Liu, B. J. Orr, “Simultaneous multi-laser, multi-species trace-level sensing of gas mixtures by rapidly swept continuous-wave cavity-ringdown spectroscopy,” Opt. Express 18(19), 20059–20071 (2010).
[CrossRef] [PubMed]

2009 (1)

C. L. Bell, M. Dhib, G. Hancock, G. A. D. Ritchie, J. H. van Helden, N. J. van Leeuwen, “Cavity enhanced absorption spectroscopy measurements of pressure-induced broadening and shift coefficients in the υ1 + υ3 combination band of ammonia,” Appl. Phys. B 94(2), 327–336 (2009).
[CrossRef]

2008 (3)

M. A. Sutton, J. W. Erisman, F. Dentener, D. Möller, “Ammonia in the environment: from ancient times to the present,” Environ. Pollut. 156(3), 583–604 (2008).
[CrossRef] [PubMed]

C. Wang, N. Srivastava, B. A. Jones, R. B. Reese, “A novel multiple species ringdown spectrometer for in situ measurements of methane, carbon dioxide, and carbon isotope,” Appl. Phys. B 92(2), 259–270 (2008).
[CrossRef]

E. R. Crosson, “A cavity ring-down analyzer for measuring atmospheric levels of methane, carbon dioxide, and water vapor,” Appl. Phys. B 92(3), 403–408 (2008).
[CrossRef]

2007 (1)

2006 (2)

R. Kan, W. Liu, Y. Zhang, J. Liu, M. Wang, D. Chen, J. Chen, Y. Cui, “Large scale gas leakage monitoring with tunable diode laser absorption spectroscopy,” Chin. Opt. Lett. 4, 116–118 (2006).

Y. He, B. J. Orr, “Detection of trace gases by rapidly-swept continuous-wave cavity ringdown spectroscopy: pushing the limits of sensitivity,” Appl. Phys. B 85(2-3), 355–364 (2006).
[CrossRef]

2005 (5)

B. A. Paldus, A. A. Kachanov, “An historical overview of cavity-enhanced methods,” Can. J. Phys. 83(10), 975–999 (2005).
[CrossRef]

M. Mazurenka, A. J. Orr-Ewing, R. R. Peverall, G. A. D. Ritchie, “Cavity ring-down and cavity enhanced spectroscopy using diode lasers,” Ann. Rep. Prog. Chem. C: Phys. Chem. 101, 100–142 (2005).
[CrossRef]

A. A. Kachanov, E. R. Crosson, B. A. Paldus, “Tunable diode lasers: expanding the horizon for laser absorption spectroscopy,” Opt. Photonics News 16(7), 44–50 (2005).
[CrossRef]

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Y. He, B. J. Orr, “Continuous-wave cavity ringdown absorption spectroscopy with a swept-frequency laser: rapid spectral sensing of gas-phase molecules,” Appl. Opt. 44(31), 6752–6761 (2005).
[CrossRef] [PubMed]

2004 (1)

Y. He, B. J. Orr, “Rapid measurement of cavity ringdown absorption spectra with a swept-frequency laser,” Appl. Phys. B 79(8), 941–945 (2004).
[CrossRef]

2003 (1)

B. G. Fidric, R. A. Provençal, S. M. Tan, E. R. Crosson, A. A. Kachanov, B. A. Paldus, “Bananas, explosives and the future of cavity ring-down spectroscopy,” Opt. Photon. News 14(7), 24–29 (2003).
[CrossRef]

2002 (5)

B. Bakowski, L. Corner, G. Hancock, R. Kotchie, R. Peverall, G. A. D. Ritchie, “Cavity-enhanced absorption spectroscopy with a rapidly swept diode laser,” Appl. Phys. B 75(6-7), 745–750 (2002).
[CrossRef]

B. L. Fawcett, A. M. Parkes, D. E. Shallcross, A. J. Orr-Ewing, “Trace detection of methane using continuous wave cavity ring-down spectroscopy at 1.65 μm,” Phys. Chem. Chem. Phys. 4(24), 5960–5965 (2002).
[CrossRef]

Y. He, B. J. Orr, “Rapidly swept, continuous-wave cavity ringdown spectroscopy with optical heterodyne detection: single- and multi-wavelength sensing of gases,” Appl. Phys. B 75(2-3), 267–280 (2002).
[CrossRef]

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

J. Morville, D. Romanini, M. Chenevier, A. Kachanov, “Effects of laser phase noise on the injection of a high-finesse cavity,” Appl. Opt. 41(33), 6980–6990 (2002).
[CrossRef] [PubMed]

2001 (2)

Y. He, B. J. Orr, “Optical heterodyne signal generation and detection in cavity ringdown spectroscopy based on a rapidly swept cavity,” Chem. Phys. Lett. 335(3-4), 215–220 (2001).
[CrossRef]

M. E. Webber, D. S. Baer, R. K. Hanson, “Ammonia monitoring near 1.5 µm with diode-laser absorption sensors,” Appl. Opt. 40(12), 2031–2042 (2001).
[CrossRef] [PubMed]

2000 (6)

B. A. Paldus, C. C. Harb, T. G. Spence, R. N. Zare, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, A. L. Hutchinson, A. Y. Cho, “Cavity ringdown spectroscopy using mid-infrared quantum-cascade lasers,” Opt. Lett. 25(9), 666–668 (2000).
[CrossRef] [PubMed]

M. D. Levenson, B. A. Paldus, T. G. Spence, C. C. Harb, R. N. Zare, M. J. Lawrence, R. L. Byer, “Frequency-switched heterodyne cavity ringdown spectroscopy,” Opt. Lett. 25(12), 920–922 (2000).
[CrossRef] [PubMed]

R. Peeters, G. Berden, A. Apituley, G. Meijer, “Open-path trace gas detection of ammonia based on cavity-enhanced absorption spectroscopy,” Appl. Phys. B 71(2), 231–236 (2000).
[CrossRef]

Y. He, B. J. Orr, “Ringdown and cavity-enhanced absorption spectroscopy using a continuous-wave tunable diode laser and a rapidly swept optical cavity,” Chem. Phys. Lett. 319(1-2), 131–137 (2000).
[CrossRef]

G. Berden, R. Peeters, G. Meijer, “Cavity ring-down spectroscopy: experimental schemes and applications,” Int. Rev. Phys. Chem. 19(4), 565–607 (2000).
[CrossRef]

T. G. Spence, C. C. Harb, B. A. Paldus, R. N. Zare, B. Willke, R. L. Byer, “A laser-locked cavity ring-down spectrometer employing an analog detection scheme,” Rev. Sci. Instrum. 71(2), 347–353 (2000).
[CrossRef]

1999 (2)

1997 (1)

1993 (1)

L. Lundsberg-Nielsen, F. Hegelund, F. M. Nicolaisen, “Analysis of the high-resolution spectrum of ammonia (14NH3) in the near-infrared region, 6400–6900 cm–1,” J. Mol. Spectrosc. 162(1), 230–245 (1993).
[CrossRef]

Anderson, T.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Apituley, A.

R. Peeters, G. Berden, A. Apituley, G. Meijer, “Open-path trace gas detection of ammonia based on cavity-enhanced absorption spectroscopy,” Appl. Phys. B 71(2), 231–236 (2000).
[CrossRef]

Baer, D. S.

Baillargeon, J. N.

Bakowski, B.

B. Bakowski, L. Corner, G. Hancock, R. Kotchie, R. Peverall, G. A. D. Ritchie, “Cavity-enhanced absorption spectroscopy with a rapidly swept diode laser,” Appl. Phys. B 75(6-7), 745–750 (2002).
[CrossRef]

Bash, J. O.

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

Bell, C. L.

C. L. Bell, M. Dhib, G. Hancock, G. A. D. Ritchie, J. H. van Helden, N. J. van Leeuwen, “Cavity enhanced absorption spectroscopy measurements of pressure-induced broadening and shift coefficients in the υ1 + υ3 combination band of ammonia,” Appl. Phys. B 94(2), 327–336 (2009).
[CrossRef]

Berden, G.

G. Berden, R. Peeters, G. Meijer, “Cavity ring-down spectroscopy: experimental schemes and applications,” Int. Rev. Phys. Chem. 19(4), 565–607 (2000).
[CrossRef]

R. Peeters, G. Berden, A. Apituley, G. Meijer, “Open-path trace gas detection of ammonia based on cavity-enhanced absorption spectroscopy,” Appl. Phys. B 71(2), 231–236 (2000).
[CrossRef]

Bergamaschi, P.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Bergmann, D.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Bethea, C. G.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Blackall, T.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Blake, D. R.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Blom, M.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Bousquet, P.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Braban, C. F.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Bretenaker, F.

Bruhwiler, L.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Buemi, M.

G. Neri, A. Lacquaniti, G. Rizzo, N. Donato, M. Latino, M. Buemi, “Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques,” Nephrol. Dial. Transplant. 27(7), 2945–2952 (2012).
[CrossRef] [PubMed]

Burba, G.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Byer, R. L.

Cameron-Smith, P.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Canadell, J. G.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Capasso, F.

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

B. A. Paldus, C. C. Harb, T. G. Spence, R. N. Zare, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, A. L. Hutchinson, A. Y. Cho, “Cavity ringdown spectroscopy using mid-infrared quantum-cascade lasers,” Opt. Lett. 25(9), 666–668 (2000).
[CrossRef] [PubMed]

Castaldi, S.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Chen, D.

Chen, J.

Chenevier, M.

Chevallier, F.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Cho, A. Y.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

B. A. Paldus, C. C. Harb, T. G. Spence, R. N. Zare, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, A. L. Hutchinson, A. Y. Cho, “Cavity ringdown spectroscopy using mid-infrared quantum-cascade lasers,” Opt. Lett. 25(9), 666–668 (2000).
[CrossRef] [PubMed]

Ciais, P.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Coe, H.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Colombelli, R.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Cooter, E. J.

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

Corner, L.

B. Bakowski, L. Corner, G. Hancock, R. Kotchie, R. Peverall, G. A. D. Ritchie, “Cavity-enhanced absorption spectroscopy with a rapidly swept diode laser,” Appl. Phys. B 75(6-7), 745–750 (2002).
[CrossRef]

Crosson, E. R.

E. R. Crosson, “A cavity ring-down analyzer for measuring atmospheric levels of methane, carbon dioxide, and water vapor,” Appl. Phys. B 92(3), 403–408 (2008).
[CrossRef]

A. A. Kachanov, E. R. Crosson, B. A. Paldus, “Tunable diode lasers: expanding the horizon for laser absorption spectroscopy,” Opt. Photonics News 16(7), 44–50 (2005).
[CrossRef]

B. G. Fidric, R. A. Provençal, S. M. Tan, E. R. Crosson, A. A. Kachanov, B. A. Paldus, “Bananas, explosives and the future of cavity ring-down spectroscopy,” Opt. Photon. News 14(7), 24–29 (2003).
[CrossRef]

Cui, Y.

Curl, R. F.

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

Dentener, F.

M. A. Sutton, J. W. Erisman, F. Dentener, D. Möller, “Ammonia in the environment: from ancient times to the present,” Environ. Pollut. 156(3), 583–604 (2008).
[CrossRef] [PubMed]

Dhib, M.

C. L. Bell, M. Dhib, G. Hancock, G. A. D. Ritchie, J. H. van Helden, N. J. van Leeuwen, “Cavity enhanced absorption spectroscopy measurements of pressure-induced broadening and shift coefficients in the υ1 + υ3 combination band of ammonia,” Appl. Phys. B 94(2), 327–336 (2009).
[CrossRef]

Dlugokencky, E. J.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Donato, N.

G. Neri, A. Lacquaniti, G. Rizzo, N. Donato, M. Latino, M. Buemi, “Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques,” Nephrol. Dial. Transplant. 27(7), 2945–2952 (2012).
[CrossRef] [PubMed]

Ellis, R.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Englich, F. V.

Erisman, J. W.

M. A. Sutton, J. W. Erisman, F. Dentener, D. Möller, “Ammonia in the environment: from ancient times to the present,” Environ. Pollut. 156(3), 583–604 (2008).
[CrossRef] [PubMed]

Famulari, D.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Fawcett, B. L.

B. L. Fawcett, A. M. Parkes, D. E. Shallcross, A. J. Orr-Ewing, “Trace detection of methane using continuous wave cavity ring-down spectroscopy at 1.65 μm,” Phys. Chem. Chem. Phys. 4(24), 5960–5965 (2002).
[CrossRef]

Feng, L.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Fidric, B. G.

B. G. Fidric, R. A. Provençal, S. M. Tan, E. R. Crosson, A. A. Kachanov, B. A. Paldus, “Bananas, explosives and the future of cavity ring-down spectroscopy,” Opt. Photon. News 14(7), 24–29 (2003).
[CrossRef]

Flechard, C. R.

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

Forsblom, C.

F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
[CrossRef] [PubMed]

Fraser, A.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Fraser, P. J.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Gallagher, M.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Gamble, H. A.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Ghalaieny, M.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Gmachl, C.

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

B. A. Paldus, C. C. Harb, T. G. Spence, R. N. Zare, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, A. L. Hutchinson, A. Y. Cho, “Cavity ringdown spectroscopy using mid-infrared quantum-cascade lasers,” Opt. Lett. 25(9), 666–668 (2000).
[CrossRef] [PubMed]

Groop, P.-H.

F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
[CrossRef] [PubMed]

Gustafson, E. K.

Hahn, J. W.

Halonen, L.

F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
[CrossRef] [PubMed]

O. Vaittinen, F. M. Schmidt, M. Metsälä, L. Halonen, “Exhaled breath biomonitoring using laser spectroscopy,” Current Analyt. Chem. 9(3), 463–475 (2013).
[CrossRef]

Hancock, G.

C. L. Bell, M. Dhib, G. Hancock, G. A. D. Ritchie, J. H. van Helden, N. J. van Leeuwen, “Cavity enhanced absorption spectroscopy measurements of pressure-induced broadening and shift coefficients in the υ1 + υ3 combination band of ammonia,” Appl. Phys. B 94(2), 327–336 (2009).
[CrossRef]

B. Bakowski, L. Corner, G. Hancock, R. Kotchie, R. Peverall, G. A. D. Ritchie, “Cavity-enhanced absorption spectroscopy with a rapidly swept diode laser,” Appl. Phys. B 75(6-7), 745–750 (2002).
[CrossRef]

Hanson, R. K.

Harb, C. C.

Harris, D. B.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Hashmonay, R. A.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Hastings, S.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

He, Y.

B. J. Orr, Y. He, “Rapidly swept continuous-wave cavity-ringdown spectroscopy,” Chem. Phys. Lett. 512(1-3), 1–20 (2011).
[CrossRef]

Y. He, R. Kan, F. V. Englich, W. Liu, B. J. Orr, “Simultaneous multi-laser, multi-species trace-level sensing of gas mixtures by rapidly swept continuous-wave cavity-ringdown spectroscopy,” Opt. Express 18(19), 20059–20071 (2010).
[CrossRef] [PubMed]

Y. He, B. J. Orr, “Detection of trace gases by rapidly-swept continuous-wave cavity ringdown spectroscopy: pushing the limits of sensitivity,” Appl. Phys. B 85(2-3), 355–364 (2006).
[CrossRef]

Y. He, B. J. Orr, “Continuous-wave cavity ringdown absorption spectroscopy with a swept-frequency laser: rapid spectral sensing of gas-phase molecules,” Appl. Opt. 44(31), 6752–6761 (2005).
[CrossRef] [PubMed]

Y. He, B. J. Orr, “Rapid measurement of cavity ringdown absorption spectra with a swept-frequency laser,” Appl. Phys. B 79(8), 941–945 (2004).
[CrossRef]

Y. He, B. J. Orr, “Rapidly swept, continuous-wave cavity ringdown spectroscopy with optical heterodyne detection: single- and multi-wavelength sensing of gases,” Appl. Phys. B 75(2-3), 267–280 (2002).
[CrossRef]

Y. He, B. J. Orr, “Optical heterodyne signal generation and detection in cavity ringdown spectroscopy based on a rapidly swept cavity,” Chem. Phys. Lett. 335(3-4), 215–220 (2001).
[CrossRef]

Y. He, B. J. Orr, “Ringdown and cavity-enhanced absorption spectroscopy using a continuous-wave tunable diode laser and a rapidly swept optical cavity,” Chem. Phys. Lett. 319(1-2), 131–137 (2000).
[CrossRef]

Hegelund, F.

L. Lundsberg-Nielsen, F. Hegelund, F. M. Nicolaisen, “Analysis of the high-resolution spectrum of ammonia (14NH3) in the near-infrared region, 6400–6900 cm–1,” J. Mol. Spectrosc. 162(1), 230–245 (1993).
[CrossRef]

Heimann, M.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Hodson, E. L.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Houweling, S.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Husman, M. E.

Hutchinson, A. L.

Hwang, H. Y.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Jones, B. A.

C. Wang, N. Srivastava, B. A. Jones, R. B. Reese, “A novel multiple species ringdown spectrometer for in situ measurements of methane, carbon dioxide, and carbon isotope,” Appl. Phys. B 92(2), 259–270 (2008).
[CrossRef]

Jones, S. K.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Josse, B.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Junninen, H.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Kachanov, A.

Kachanov, A. A.

B. A. Paldus, A. A. Kachanov, “An historical overview of cavity-enhanced methods,” Can. J. Phys. 83(10), 975–999 (2005).
[CrossRef]

A. A. Kachanov, E. R. Crosson, B. A. Paldus, “Tunable diode lasers: expanding the horizon for laser absorption spectroscopy,” Opt. Photonics News 16(7), 44–50 (2005).
[CrossRef]

B. G. Fidric, R. A. Provençal, S. M. Tan, E. R. Crosson, A. A. Kachanov, B. A. Paldus, “Bananas, explosives and the future of cavity ring-down spectroscopy,” Opt. Photon. News 14(7), 24–29 (2003).
[CrossRef]

Kan, R.

Kim, J. W.

Kirschke, S.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Komissarov, A.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Kosterev, A. A.

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

Kotchie, R.

B. Bakowski, L. Corner, G. Hancock, R. Kotchie, R. Peverall, G. A. D. Ritchie, “Cavity-enhanced absorption spectroscopy with a rapidly swept diode laser,” Appl. Phys. B 75(6-7), 745–750 (2002).
[CrossRef]

Krummel, P. B.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Lacquaniti, A.

G. Neri, A. Lacquaniti, G. Rizzo, N. Donato, M. Latino, M. Buemi, “Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques,” Nephrol. Dial. Transplant. 27(7), 2945–2952 (2012).
[CrossRef] [PubMed]

Lamarque, J.-F.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Langenfelds, R. L.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Latino, M.

G. Neri, A. Lacquaniti, G. Rizzo, N. Donato, M. Latino, M. Buemi, “Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques,” Nephrol. Dial. Transplant. 27(7), 2945–2952 (2012).
[CrossRef] [PubMed]

Lawrence, M. J.

Le Floch, A.

Le Quéré, C.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Lee, H.-W.

Lee, J. Y.

Lehto, M.

F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
[CrossRef] [PubMed]

Levenson, M. D.

Lewicki, R.

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

Liu, H. C.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Liu, J.

Liu, W.

Loubet, B.

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

Lundsberg-Nielsen, L.

L. Lundsberg-Nielsen, F. Hegelund, F. M. Nicolaisen, “Analysis of the high-resolution spectrum of ammonia (14NH3) in the near-infrared region, 6400–6900 cm–1,” J. Mol. Spectrosc. 162(1), 230–245 (1993).
[CrossRef]

Massad, R.-S.

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

Mazurenka, M.

M. Mazurenka, A. J. Orr-Ewing, R. R. Peverall, G. A. D. Ritchie, “Cavity ring-down and cavity enhanced spectroscopy using diode lasers,” Ann. Rep. Prog. Chem. C: Phys. Chem. 101, 100–142 (2005).
[CrossRef]

McDermitt, D.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

McGillen, M. R.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

McManus, B.

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

Meijer, G.

R. Peeters, G. Berden, A. Apituley, G. Meijer, “Open-path trace gas detection of ammonia based on cavity-enhanced absorption spectroscopy,” Appl. Phys. B 71(2), 231–236 (2000).
[CrossRef]

G. Berden, R. Peeters, G. Meijer, “Cavity ring-down spectroscopy: experimental schemes and applications,” Int. Rev. Phys. Chem. 19(4), 565–607 (2000).
[CrossRef]

Metsälä, M.

O. Vaittinen, F. M. Schmidt, M. Metsälä, L. Halonen, “Exhaled breath biomonitoring using laser spectroscopy,” Current Analyt. Chem. 9(3), 463–475 (2013).
[CrossRef]

F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
[CrossRef] [PubMed]

Modrak, M. T.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Mohacsi, A.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Möller, D.

M. A. Sutton, J. W. Erisman, F. Dentener, D. Möller, “Ammonia in the environment: from ancient times to the present,” Environ. Pollut. 156(3), 583–604 (2008).
[CrossRef] [PubMed]

Morville, J.

Murphy, J.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Myers, T. L.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Naik, V.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Natschke, D. F.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Nemitz, E.

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Neri, G.

G. Neri, A. Lacquaniti, G. Rizzo, N. Donato, M. Latino, M. Buemi, “Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques,” Nephrol. Dial. Transplant. 27(7), 2945–2952 (2012).
[CrossRef] [PubMed]

Nicolaisen, F. M.

L. Lundsberg-Nielsen, F. Hegelund, F. M. Nicolaisen, “Analysis of the high-resolution spectrum of ammonia (14NH3) in the near-infrared region, 6400–6900 cm–1,” J. Mol. Spectrosc. 162(1), 230–245 (1993).
[CrossRef]

O’Doherty, S.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Oberbauer, S.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Oeschel, W.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Orr, B. J.

B. J. Orr, Y. He, “Rapidly swept continuous-wave cavity-ringdown spectroscopy,” Chem. Phys. Lett. 512(1-3), 1–20 (2011).
[CrossRef]

Y. He, R. Kan, F. V. Englich, W. Liu, B. J. Orr, “Simultaneous multi-laser, multi-species trace-level sensing of gas mixtures by rapidly swept continuous-wave cavity-ringdown spectroscopy,” Opt. Express 18(19), 20059–20071 (2010).
[CrossRef] [PubMed]

Y. He, B. J. Orr, “Detection of trace gases by rapidly-swept continuous-wave cavity ringdown spectroscopy: pushing the limits of sensitivity,” Appl. Phys. B 85(2-3), 355–364 (2006).
[CrossRef]

Y. He, B. J. Orr, “Continuous-wave cavity ringdown absorption spectroscopy with a swept-frequency laser: rapid spectral sensing of gas-phase molecules,” Appl. Opt. 44(31), 6752–6761 (2005).
[CrossRef] [PubMed]

Y. He, B. J. Orr, “Rapid measurement of cavity ringdown absorption spectra with a swept-frequency laser,” Appl. Phys. B 79(8), 941–945 (2004).
[CrossRef]

Y. He, B. J. Orr, “Rapidly swept, continuous-wave cavity ringdown spectroscopy with optical heterodyne detection: single- and multi-wavelength sensing of gases,” Appl. Phys. B 75(2-3), 267–280 (2002).
[CrossRef]

Y. He, B. J. Orr, “Optical heterodyne signal generation and detection in cavity ringdown spectroscopy based on a rapidly swept cavity,” Chem. Phys. Lett. 335(3-4), 215–220 (2001).
[CrossRef]

Y. He, B. J. Orr, “Ringdown and cavity-enhanced absorption spectroscopy using a continuous-wave tunable diode laser and a rapidly swept optical cavity,” Chem. Phys. Lett. 319(1-2), 131–137 (2000).
[CrossRef]

Orr-Ewing, A. J.

M. Mazurenka, A. J. Orr-Ewing, R. R. Peverall, G. A. D. Ritchie, “Cavity ring-down and cavity enhanced spectroscopy using diode lasers,” Ann. Rep. Prog. Chem. C: Phys. Chem. 101, 100–142 (2005).
[CrossRef]

B. L. Fawcett, A. M. Parkes, D. E. Shallcross, A. J. Orr-Ewing, “Trace detection of methane using continuous wave cavity ring-down spectroscopy at 1.65 μm,” Phys. Chem. Chem. Phys. 4(24), 5960–5965 (2002).
[CrossRef]

Paldus, B. A.

A. A. Kachanov, E. R. Crosson, B. A. Paldus, “Tunable diode lasers: expanding the horizon for laser absorption spectroscopy,” Opt. Photonics News 16(7), 44–50 (2005).
[CrossRef]

B. A. Paldus, A. A. Kachanov, “An historical overview of cavity-enhanced methods,” Can. J. Phys. 83(10), 975–999 (2005).
[CrossRef]

B. G. Fidric, R. A. Provençal, S. M. Tan, E. R. Crosson, A. A. Kachanov, B. A. Paldus, “Bananas, explosives and the future of cavity ring-down spectroscopy,” Opt. Photon. News 14(7), 24–29 (2003).
[CrossRef]

T. G. Spence, C. C. Harb, B. A. Paldus, R. N. Zare, B. Willke, R. L. Byer, “A laser-locked cavity ring-down spectrometer employing an analog detection scheme,” Rev. Sci. Instrum. 71(2), 347–353 (2000).
[CrossRef]

M. D. Levenson, B. A. Paldus, T. G. Spence, C. C. Harb, R. N. Zare, M. J. Lawrence, R. L. Byer, “Frequency-switched heterodyne cavity ringdown spectroscopy,” Opt. Lett. 25(12), 920–922 (2000).
[CrossRef] [PubMed]

B. A. Paldus, C. C. Harb, T. G. Spence, R. N. Zare, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, A. L. Hutchinson, A. Y. Cho, “Cavity ringdown spectroscopy using mid-infrared quantum-cascade lasers,” Opt. Lett. 25(9), 666–668 (2000).
[CrossRef] [PubMed]

Palmer, P. I.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Parkes, A. M.

B. L. Fawcett, A. M. Parkes, D. E. Shallcross, A. J. Orr-Ewing, “Trace detection of methane using continuous wave cavity ring-down spectroscopy at 1.65 μm,” Phys. Chem. Chem. Phys. 4(24), 5960–5965 (2002).
[CrossRef]

Peeters, R.

R. Peeters, G. Berden, A. Apituley, G. Meijer, “Open-path trace gas detection of ammonia based on cavity-enhanced absorption spectroscopy,” Appl. Phys. B 71(2), 231–236 (2000).
[CrossRef]

G. Berden, R. Peeters, G. Meijer, “Cavity ring-down spectroscopy: experimental schemes and applications,” Int. Rev. Phys. Chem. 19(4), 565–607 (2000).
[CrossRef]

Percival, C. J.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Personne, E.

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

Peverall, R.

B. Bakowski, L. Corner, G. Hancock, R. Kotchie, R. Peverall, G. A. D. Ritchie, “Cavity-enhanced absorption spectroscopy with a rapidly swept diode laser,” Appl. Phys. B 75(6-7), 745–750 (2002).
[CrossRef]

Peverall, R. R.

M. Mazurenka, A. J. Orr-Ewing, R. R. Peverall, G. A. D. Ritchie, “Cavity ring-down and cavity enhanced spectroscopy using diode lasers,” Ann. Rep. Prog. Chem. C: Phys. Chem. 101, 100–142 (2005).
[CrossRef]

Pison, I.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Plummer, D.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Pogany, A.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Poirson, J.

Poulter, B.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Prinn, R. G.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Provençal, R. A.

B. G. Fidric, R. A. Provençal, S. M. Tan, E. R. Crosson, A. A. Kachanov, B. A. Paldus, “Bananas, explosives and the future of cavity ring-down spectroscopy,” Opt. Photon. News 14(7), 24–29 (2003).
[CrossRef]

Pusharsky, M.

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

Rantanen, S.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Reese, R. B.

C. Wang, N. Srivastava, B. A. Jones, R. B. Reese, “A novel multiple species ringdown spectrometer for in situ measurements of methane, carbon dioxide, and carbon isotope,” Appl. Phys. B 92(2), 259–270 (2008).
[CrossRef]

Riensche, B.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Rigby, M.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Ringeval, B.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Ritchie, G. A. D.

C. L. Bell, M. Dhib, G. Hancock, G. A. D. Ritchie, J. H. van Helden, N. J. van Leeuwen, “Cavity enhanced absorption spectroscopy measurements of pressure-induced broadening and shift coefficients in the υ1 + υ3 combination band of ammonia,” Appl. Phys. B 94(2), 327–336 (2009).
[CrossRef]

M. Mazurenka, A. J. Orr-Ewing, R. R. Peverall, G. A. D. Ritchie, “Cavity ring-down and cavity enhanced spectroscopy using diode lasers,” Ann. Rep. Prog. Chem. C: Phys. Chem. 101, 100–142 (2005).
[CrossRef]

B. Bakowski, L. Corner, G. Hancock, R. Kotchie, R. Peverall, G. A. D. Ritchie, “Cavity-enhanced absorption spectroscopy with a rapidly swept diode laser,” Appl. Phys. B 75(6-7), 745–750 (2002).
[CrossRef]

Rizzo, G.

G. Neri, A. Lacquaniti, G. Rizzo, N. Donato, M. Latino, M. Buemi, “Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques,” Nephrol. Dial. Transplant. 27(7), 2945–2952 (2012).
[CrossRef] [PubMed]

Romanini, D.

Santini, M.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Saunois, M.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Schedlbauer, J.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Schmidt, F. M.

O. Vaittinen, F. M. Schmidt, M. Metsälä, L. Halonen, “Exhaled breath biomonitoring using laser spectroscopy,” Current Analyt. Chem. 9(3), 463–475 (2013).
[CrossRef]

F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
[CrossRef] [PubMed]

Schmidt, M.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Sergent, A. M.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Shallcross, D. E.

B. L. Fawcett, A. M. Parkes, D. E. Shallcross, A. J. Orr-Ewing, “Trace detection of methane using continuous wave cavity ring-down spectroscopy at 1.65 μm,” Phys. Chem. Chem. Phys. 4(24), 5960–5965 (2002).
[CrossRef]

Shindell, D. T.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Shores, R. C.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Simpson, D.

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

Simpson, I. J.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Sivco, D. L.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

B. A. Paldus, C. C. Harb, T. G. Spence, R. N. Zare, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, A. L. Hutchinson, A. Y. Cho, “Cavity ringdown spectroscopy using mid-infrared quantum-cascade lasers,” Opt. Lett. 25(9), 666–668 (2000).
[CrossRef] [PubMed]

Smith, T. E. L.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Spahni, R.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Spence, T. G.

Srivastava, N.

C. Wang, N. Srivastava, B. A. Jones, R. B. Reese, “A novel multiple species ringdown spectrometer for in situ measurements of methane, carbon dioxide, and carbon isotope,” Appl. Phys. B 92(2), 259–270 (2008).
[CrossRef]

Starr, G.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Steele, L. P.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Strode, S. A.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Sudo, K.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Sutton, M. A.

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

M. A. Sutton, J. W. Erisman, F. Dentener, D. Möller, “Ammonia in the environment: from ancient times to the present,” Environ. Pollut. 156(3), 583–604 (2008).
[CrossRef] [PubMed]

Szopa, S.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Tan, S. M.

B. G. Fidric, R. A. Provençal, S. M. Tan, E. R. Crosson, A. A. Kachanov, B. A. Paldus, “Bananas, explosives and the future of cavity ring-down spectroscopy,” Opt. Photon. News 14(7), 24–29 (2003).
[CrossRef]

Taubman, M. S.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Thoma, E. D.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Thompson, E. L.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Thorneloe, S. A.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

Tittel, F. K.

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

Unterrainer, K.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Vaittinen, O.

F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
[CrossRef] [PubMed]

O. Vaittinen, F. M. Schmidt, M. Metsälä, L. Halonen, “Exhaled breath biomonitoring using laser spectroscopy,” Current Analyt. Chem. 9(3), 463–475 (2013).
[CrossRef]

Vallet, M.

van der Werf, G. R.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

van Helden, J. H.

C. L. Bell, M. Dhib, G. Hancock, G. A. D. Ritchie, J. H. van Helden, N. J. van Leeuwen, “Cavity enhanced absorption spectroscopy measurements of pressure-induced broadening and shift coefficients in the υ1 + υ3 combination band of ammonia,” Appl. Phys. B 94(2), 327–336 (2009).
[CrossRef]

van Leeuwen, N. J.

C. L. Bell, M. Dhib, G. Hancock, G. A. D. Ritchie, J. H. van Helden, N. J. van Leeuwen, “Cavity enhanced absorption spectroscopy measurements of pressure-induced broadening and shift coefficients in the υ1 + υ3 combination band of ammonia,” Appl. Phys. B 94(2), 327–336 (2009).
[CrossRef]

van Weele, M.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Varma, R. M.

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

von Bobrutzki, K.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Voulgarakis, A.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Wang, C.

C. Wang, N. Srivastava, B. A. Jones, R. B. Reese, “A novel multiple species ringdown spectrometer for in situ measurements of methane, carbon dioxide, and carbon isotope,” Appl. Phys. B 92(2), 259–270 (2008).
[CrossRef]

Wang, M.

Webber, M. E.

Weiss, R. F.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Whitehead, J. D.

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Whittaker, E. A.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Wilke, B.

Williams, J. E.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Williams, R. M.

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Willke, B.

T. G. Spence, C. C. Harb, B. A. Paldus, R. N. Zare, B. Willke, R. L. Byer, “A laser-locked cavity ring-down spectrometer employing an analog detection scheme,” Rev. Sci. Instrum. 71(2), 347–353 (2000).
[CrossRef]

Wysocki, G.

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

Xu, L.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Yoo, Y. S.

Zare, R. N.

Zeng, G.

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Zhang, Y.

Zona, D.

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Ann. Rep. Prog. Chem. C: Phys. Chem. (1)

M. Mazurenka, A. J. Orr-Ewing, R. R. Peverall, G. A. D. Ritchie, “Cavity ring-down and cavity enhanced spectroscopy using diode lasers,” Ann. Rep. Prog. Chem. C: Phys. Chem. 101, 100–142 (2005).
[CrossRef]

Appl. Opt. (4)

Appl. Phys. B (9)

E. R. Crosson, “A cavity ring-down analyzer for measuring atmospheric levels of methane, carbon dioxide, and water vapor,” Appl. Phys. B 92(3), 403–408 (2008).
[CrossRef]

Y. He, B. J. Orr, “Rapid measurement of cavity ringdown absorption spectra with a swept-frequency laser,” Appl. Phys. B 79(8), 941–945 (2004).
[CrossRef]

C. L. Bell, M. Dhib, G. Hancock, G. A. D. Ritchie, J. H. van Helden, N. J. van Leeuwen, “Cavity enhanced absorption spectroscopy measurements of pressure-induced broadening and shift coefficients in the υ1 + υ3 combination band of ammonia,” Appl. Phys. B 94(2), 327–336 (2009).
[CrossRef]

R. Peeters, G. Berden, A. Apituley, G. Meijer, “Open-path trace gas detection of ammonia based on cavity-enhanced absorption spectroscopy,” Appl. Phys. B 71(2), 231–236 (2000).
[CrossRef]

B. Bakowski, L. Corner, G. Hancock, R. Kotchie, R. Peverall, G. A. D. Ritchie, “Cavity-enhanced absorption spectroscopy with a rapidly swept diode laser,” Appl. Phys. B 75(6-7), 745–750 (2002).
[CrossRef]

D. McDermitt, G. Burba, L. Xu, T. Anderson, A. Komissarov, B. Riensche, J. Schedlbauer, G. Starr, D. Zona, W. Oeschel, S. Oberbauer, S. Hastings, “A new low-power, open-path instrument for measuring methane flux by eddy covariance,” Appl. Phys. B 102(2), 391–405 (2011).
[CrossRef]

Y. He, B. J. Orr, “Detection of trace gases by rapidly-swept continuous-wave cavity ringdown spectroscopy: pushing the limits of sensitivity,” Appl. Phys. B 85(2-3), 355–364 (2006).
[CrossRef]

Y. He, B. J. Orr, “Rapidly swept, continuous-wave cavity ringdown spectroscopy with optical heterodyne detection: single- and multi-wavelength sensing of gases,” Appl. Phys. B 75(2-3), 267–280 (2002).
[CrossRef]

C. Wang, N. Srivastava, B. A. Jones, R. B. Reese, “A novel multiple species ringdown spectrometer for in situ measurements of methane, carbon dioxide, and carbon isotope,” Appl. Phys. B 92(2), 259–270 (2008).
[CrossRef]

Atmospheric Measurement Techniques (1)

K. von Bobrutzki, C. F. Braban, D. Famulari, S. K. Jones, T. Blackall, T. E. L. Smith, M. Blom, H. Coe, M. Gallagher, M. Ghalaieny, M. R. McGillen, C. J. Percival, J. D. Whitehead, R. Ellis, J. Murphy, A. Mohacsi, A. Pogany, H. Junninen, S. Rantanen, M. A. Sutton, E. Nemitz, “Field inter-comparison of eleven atmospheric ammonia measurement techniques,” Atmospheric Measurement Techniques 3(1), 91–112 (2010).
[CrossRef]

Biogeosciences (1)

C. R. Flechard, R.-S. Massad, B. Loubet, E. Personne, D. Simpson, J. O. Bash, E. J. Cooter, E. Nemitz, M. A. Sutton, “Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange,” Biogeosciences 10(7), 5183–5225 (2013).
[CrossRef]

Can. J. Phys. (1)

B. A. Paldus, A. A. Kachanov, “An historical overview of cavity-enhanced methods,” Can. J. Phys. 83(10), 975–999 (2005).
[CrossRef]

Chem. Phys. Lett. (4)

B. J. Orr, Y. He, “Rapidly swept continuous-wave cavity-ringdown spectroscopy,” Chem. Phys. Lett. 512(1-3), 1–20 (2011).
[CrossRef]

R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel, “Quantum cascade lasers in chemical physics,” Chem. Phys. Lett. 487(1-3), 1–18 (2010).
[CrossRef]

Y. He, B. J. Orr, “Optical heterodyne signal generation and detection in cavity ringdown spectroscopy based on a rapidly swept cavity,” Chem. Phys. Lett. 335(3-4), 215–220 (2001).
[CrossRef]

Y. He, B. J. Orr, “Ringdown and cavity-enhanced absorption spectroscopy using a continuous-wave tunable diode laser and a rapidly swept optical cavity,” Chem. Phys. Lett. 319(1-2), 131–137 (2000).
[CrossRef]

Chin. Opt. Lett. (2)

Current Analyt. Chem. (1)

O. Vaittinen, F. M. Schmidt, M. Metsälä, L. Halonen, “Exhaled breath biomonitoring using laser spectroscopy,” Current Analyt. Chem. 9(3), 463–475 (2013).
[CrossRef]

Environ. Pollut. (1)

M. A. Sutton, J. W. Erisman, F. Dentener, D. Möller, “Ammonia in the environment: from ancient times to the present,” Environ. Pollut. 156(3), 583–604 (2008).
[CrossRef] [PubMed]

IEEE J. Quantum Electron. (1)

F. Capasso, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, E. A. Whittaker, “Quantum cascade lasers: ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron. 38(6), 511–532 (2002).
[CrossRef]

Int. Rev. Phys. Chem. (1)

G. Berden, R. Peeters, G. Meijer, “Cavity ring-down spectroscopy: experimental schemes and applications,” Int. Rev. Phys. Chem. 19(4), 565–607 (2000).
[CrossRef]

J Breath Res (1)

F. M. Schmidt, O. Vaittinen, M. Metsälä, M. Lehto, C. Forsblom, P.-H. Groop, L. Halonen, “Ammonia in breath and emitted from skin,” J Breath Res 7(1), 017109 (2013).
[CrossRef] [PubMed]

J. Air Waste Manag. Assoc. (1)

E. D. Thoma, R. C. Shores, E. L. Thompson, D. B. Harris, S. A. Thorneloe, R. M. Varma, R. A. Hashmonay, M. T. Modrak, D. F. Natschke, H. A. Gamble, “Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data,” J. Air Waste Manag. Assoc. 55(5), 658–668 (2005).
[CrossRef] [PubMed]

J. Mol. Spectrosc. (1)

L. Lundsberg-Nielsen, F. Hegelund, F. M. Nicolaisen, “Analysis of the high-resolution spectrum of ammonia (14NH3) in the near-infrared region, 6400–6900 cm–1,” J. Mol. Spectrosc. 162(1), 230–245 (1993).
[CrossRef]

J. Opt. Soc. Am. B (2)

Nat. Geosci. (1)

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, G. Zeng, “Three decades of global methane sources and sinks,” Nat. Geosci. 6(10), 813–823 (2013).
[CrossRef]

Nephrol. Dial. Transplant. (1)

G. Neri, A. Lacquaniti, G. Rizzo, N. Donato, M. Latino, M. Buemi, “Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques,” Nephrol. Dial. Transplant. 27(7), 2945–2952 (2012).
[CrossRef] [PubMed]

Opt. Express (1)

Opt. Lett. (2)

Opt. Photon. News (1)

B. G. Fidric, R. A. Provençal, S. M. Tan, E. R. Crosson, A. A. Kachanov, B. A. Paldus, “Bananas, explosives and the future of cavity ring-down spectroscopy,” Opt. Photon. News 14(7), 24–29 (2003).
[CrossRef]

Opt. Photonics News (1)

A. A. Kachanov, E. R. Crosson, B. A. Paldus, “Tunable diode lasers: expanding the horizon for laser absorption spectroscopy,” Opt. Photonics News 16(7), 44–50 (2005).
[CrossRef]

Phys. Chem. Chem. Phys. (1)

B. L. Fawcett, A. M. Parkes, D. E. Shallcross, A. J. Orr-Ewing, “Trace detection of methane using continuous wave cavity ring-down spectroscopy at 1.65 μm,” Phys. Chem. Chem. Phys. 4(24), 5960–5965 (2002).
[CrossRef]

Rev. Sci. Instrum. (1)

T. G. Spence, C. C. Harb, B. A. Paldus, R. N. Zare, B. Willke, R. L. Byer, “A laser-locked cavity ring-down spectrometer employing an analog detection scheme,” Rev. Sci. Instrum. 71(2), 347–353 (2000).
[CrossRef]

Other (19)

J. H. van Helden, R. Peverall, and G. A. D. Ritchie, “Cavity enhanced techniques using continuous wave lasers,” Chap. 2 in G. Berden and R. Engeln, eds., Cavity Ring-Down Spectroscopy: Techniques and Applications (Wiley-Blackwell, 2009), pp. 27–56.

M. C. Phillips, M. S. Taubman, B. E. Bernacki, B. D. Cannon, J. T. Schiffern, and T. L. Myers, “Design and performance of a sensor system for detection of multiple chemicals using an external cavity quantum cascade laser,” in M. Razeghi, R. Sudharsanan, and G. J. Brown, eds., Quantum Sensing and Nanophotonic Devices VII, Proc. SPIE 7608, 76080D/1–76080D/11 (2010).

D. J. Miller, K. Sun, L. Tao, M. A. Khan, and M. A. Zondlo, “Open-path, quantum cascade laser-based sensor for high resolution atmospheric ammonia measurements,” Atmos. Meas. Tech. Discuss. 6, 7005–7039 (2013); http://www.atmos-meas-tech-discuss.net/6/7005/2013/
[CrossRef]

Y. He, Y. Zhang, W. Liu, R. Kan, and H. Xia, “Atmospheric ammonia monitoring near Beijing National Stadium from July to October in 2008 by open-path TDLAS system,” in F. Amzajerdian, C-Q. Gao, T.-Y. Xie, eds., International Symposium on Photoelectronic Detection and Imaging 2009: Pt. 1 – Laser Sensing and Imaging, Proc. SPIE 7382, 73821L/1–73821L/7 (2009).

Y. He, Y. Zhang, L. Wang, K. You, Y. Gao, A. Zhu, and W. Yang, “An ammonia sensor with high sensitivity in farmland based on laser absorption spectroscopy technology,” in B. Culshaw, ed., Advanced Sensor Systems and Applications V, Proc. SPIE 8561, 85610X/1–8 5610X/7 (2012).

O. T. Denmead, D. Chen, D. Rowell, Z. Loh, J. Hill, S. Muir, D. W. T. Griffith, T. Naylor, M. Bai, F. Phillips, and S. McGinn, “Gaseous nitrogen emissions from Australian cattle feedlots,” Chapter 3 in M. A Sutton, K. E. Mason, L. J. Sheppard, H. Sverdrup, R. Haeuber, and W. K. Hicks, eds., Nitrogen Deposition, Critical Loads and Biodiversity (Springer, 2013); ISBN 978–94–007–7938–9.

B. Arnon, N. Hutchings, F. P. Vinther, P. K. Nielsem, H. D. Poulsen, I. S. Kristensen, and S. Pietrzak, “Analysis of methodologies for calculating greenhouse gas and ammonia emissions and nutrient balances,” in J. Selenius, L. Baudouin, and A. M. Kremer, eds., Eurostat Methodologies and Working Papers; ISSN 1977–0375 (European Union, 2011).
[CrossRef]

The CSIRO Flagship Livestock Methane Research Cluster (LMRC) is outlined at http://www.csiro.au/lmrc

L. S. Rothman, I. E. Gordon, Y. Babikov, A. Barbe, D. C. Benner, P. F. Bernath, M. Birk, L. Bizzocchi, V. Boudon, L. R. Brown, A. Campargue, K. Chance, E. A. Cohen, L .H. Coudert, V. M. Devi, B. J. Drouin, A. Fayt, J.-M. Flaud, R. R. Gamache, J. J. Harrison, J.-M. Hartmann, C. Hill, J. T. Hodges, D. Jacquemart, A. Jolly, J. Lamouroux, R. J. Le Roy, G. Li, D. A. Long, O. M. Lyulin, C. J. Mackie, S. T. Massie, S. Mikhailenko, H. S. P. Müller, O. V. Naumenko, A. V. Nikitin, J. Orphal, V. Perevalov, A. Perrin, E. R. Polovtseva, C. Richard, M. A. H. Smith, E. Starikova, K. Sung, S. Tashkun, J. Tennyson, G. C. Toon, Vl. G. Tyuterev, and G. Wagner, “The HITRAN2012 molecular spectroscopic database,” J. Quant. Spectrosc. Radiat. Transfer 130, 4–50 (2013); see also earlier editions of the HITRAN database (e.g., 2008 and 2004).

J. Ye, “Ultrasensitive high resolution laser spectroscopy and its application to optical frequency standards,” Ph. D. thesis (University of Colorado, 1997); note Fig. 6.2, p. 121.

J. Ye, L.-S. Ma, and J. L. Hall, “Using FM methods with molecules in a high finesse cavity: a demonstrated path to 10−12 absorption sensitivity,” Chap. 15 in K. W. Busch and M. A. Busch, eds., Cavity-Ringdown Spectroscopy: an Ultratrace-Absorption Measurement Technique, Vol. 720 of ACS Symposium Series (Am. Chem. Soc., 1999), pp. 233–253; note Fig. 3, p. 241.

M. S. Taubman, P. M. Aker, D. C. Scott, M. D. Wojcik, B. D. Cannon, J. T. Munley, T. L. Myers, V. T. Nguyen, C. A. Bonebrake, and J. F. Schultz, “Long wave infrared cavity enhanced sensors,” Pacific Northwest National Laboratory Report PNNL-15103 (October 2004), Fig. 2.1, p. 2.2. http://www.pnl.gov/main/publications/external/technical_reports/PNNL-15103.pdf

K. W. Busch and M. A. Busch, eds., Cavity-Ringdown Spectroscopy: an Ultratrace-Absorption Measurement Technique, Vol. 720 of ACS Symposium Series (Am. Chem. Soc., 1999).

G. Berden and R. Engeln, eds., Cavity Ring-Down Spectroscopy: Techniques and Applications (Wiley-Blackwell, 2009).

I. T. Sorokina and K. L. Vodopyanov, eds., Solid-State Mid-Infrared Sources (Springer, 2003).

A. B. Ruffin, “Stimulated Brillouin scattering: an overview of measurements, system impairments, and applications,” in P. A. Williams and G. W. Day, eds., Technical Digest: Symposium on Optical Fiber Measurements,2004, NIST Special Publication 1024 (National Institute of Standards and Technology, 2004), pp. 23–28; http://www.nist.gov/manuscript-publication-search.cfm?pub_id=31763

For example: Picarro, Inc., (Sunnyvale, CA 94085, USA); http://www.picarro.com/gas_analyzers

Note in particular Picarro’s G2103 and G1103 near-IR WS-CRDS (Wavelength-Scanned Cavity Ring Down Spectroscopy) NH3 analyzers; see https://picarro.app.box.com/shared/ffey0e0mo8 and http://www.picarro.com/assets/docs/NH3_analyzer_datasheet.pdf , respectively.

G. Burba and D. Anderson, A Brief Practical Guide to Eddy Covariance Flux Measurements (Li-COR Biosciences, 2010); http://www.licor.com/env/products/eddy_covariance/ec_book.html

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (10)

Fig. 1
Fig. 1

Layout of an optical-fiber-coupled rapidly swept cw-CRDS instrument, based on a swept-frequency (SF) tunable laser. The gas-phase sample is located between the reflectors of the passive high-finesse ringdown cavity, to and from which coherent near-IR radiation (bold lines) is conveyed via a three-port optical circulator (OC), single-mode optical fiber, and coupling optics. Backward-propagating light reflected from the cavity is diverted via OC to a photodetector (PD1), where it is monitored in an optical-heterodyne mode of detection. Backward- and forward-propagating ringdown-signal waveforms are shown as red and blue insets, respectively. Electric field amplitudes of light at various points in the system are denoted by EL, EI, EF, and EB.

Fig. 2
Fig. 2

Fiber-coupled SF cw-CRDS waveforms measured in reflection, using a ringdown cavity with FSR = 282 MHz and υSF ≈0.13 MHz µs–1. In Figs. 2(a)2(c), the fiber length L = 10 m, whereas L = 1 km in Fig. 2(d), where the CRDS waveforms are obscured by SBS interferences.

Fig. 3
Fig. 3

Layout of a SF cw-CRDS instrument, fiber-coupled over long distances, which uses a second optical fiber and optical circulator (OC2) to return backward-propagating light from the remote cavity to photodetector PD1 in the transmitter/receiver console, where it is monitored in OHD mode. This layout separates OHD cw-CRDS signal light (the waveform of which is inset in red) from backward-propagating SBS light (depicted by grey arrows) which is diverted by OC1 to a beam dump, thereby avoiding SBS interferences that arise in long optical fibers.

Fig. 4
Fig. 4

Alternative layout of a long-fiber-coupled SF cw-CRDS instrument for remote sensing. A second optical fiber and extra coupling optics are used to return forward-propagating cw-CRDS light transmitted by the remote cavity to photodetector PD2 in the transmitter/receiver console; this avoids SBS interferences that are generated by laser light in long (e.g., >10 m) optical fibers. A corresponding signal waveform is inset in blue. The backward-propagating light reflected from the cavity, accompanied by SBS light (labelled in grey), is diverted via OC to a beam dump.

Fig. 5
Fig. 5

SF cw-CRDS waveforms measured by using a twin-fiber-coupled forward-propagating instrument as in Fig. 4, with a pair of long (L = 1 km) optical fibers; an exponential-decay fitting curve is superimposed on plot (a). These waveforms are seen to be free of SBS interference.

Fig. 6
Fig. 6

Near-IR swept-cavity cw-CRDS absorption scan (a) for ~40 ppmv of NH3 in N2(g) at 1 atm, measured by a tunable ECDL, compared (b) with a stick spectrum from published data [55]. Asterisks mark two prominent absorption features of NH3(g) at 1522.5-nm and 1531.7-nm.

Fig. 7
Fig. 7

Higher-resolution cw-CRDS spectra (a, b, e) of NH3(g) accompanied by reference spectra, all recorded at ~1531.7 nm by slowly scanning the laser frequency. Trace (a) is SC cw-CRDS spectrum, whereas traces (b) and (e) are SF cw-CRDS spectra; all three are recorded for a mixture of 9 ± 0.5 ppmv of NH3 in N2(g) at a total pressure of 1 atm. The reference spectra (for a mixture of NH3 and CH4, each at 100 Torr in a sealed quartz cell) are recorded (c) in simple transmission mode, simultaneously with (a), and (d) in WMS mode, simultaneously with (b). Trace (e), plotted at ~1 data point/s, is further discussed in the text.

Fig. 8
Fig. 8

A passive, pre-aligned open-path ringdown-cavity sensor unit mounted for environmental sensing (a) in the laboratory, (b) on an eddy-covariance tower, and (c) in a campus garden. A pair of yellow-clad single-mode optical fibers connect the sensor unit, via free-space coupling optics, to and from the optical transmitter/receiver console that can be located far away (>1 km in experiments reported here). Gas lines to circulate filtered mirror-cleansing air are also visible.

Fig. 9
Fig. 9

SF cw-CRDS measurements continuously recorded at ~1531.7 nm, monitoring NH3(g) in air under two sets of experimental conditions, as explained in text below. Open-path measurements (a) of NH3(g) in air display rapid natural fluctuations which are substantially reduced when the analyte gas is confined (b) in an open-ended intra-cavity tube.

Fig. 10
Fig. 10

Open-path SF cw-CRDS measurements (plotted in blue) continuously recorded to sense NH3(g) emissions in outdoor air at ~1531.7-nm (a) over ~20 minutes with ensuing baseline and (b) during a 4-hour period. The red plot in Fig. 10(b) is a 300-point (~5-minute) running average (magnified ten-fold on the ordinate scale) of the rapid natural fluctuations in the instantaneous mixing ratio of NH3(g) in air. As shown in Fig. 7(c), the open-path ringdown-cavity sensor unit was mounted adjacent to a campus garden. The sensor is remotely separated by twin optical fibers (total length L ≈1.15 km) from the optical transmitter/receiver console in a nearby building. The source of NH3(g) was fertilizer on a ~0.2-m2 bed of straw in the garden (see text).

Metrics