A calculation of the absorption cross section of some molecules (NH3, C2H4, CO2, O3, NO2, PH3, HNO3, SF6, CH3OH, HCOOH, OCS, CH3CN, C2H6, SO2, and H2O) at the wavelengths transmitted by a CO2 laser filled with different isotopes (12C16O2, 13C16O2, 12C18O2, 14C16O2, 14C18O2, 13C18O2, and 12C16O18O) is presented. The spectroscopical parameters for the molecules from GEISA database have been used. Hence the selection of the molecules was substantially based on the availability of the parameters in the database. The results of the calculations may be used in designing the differential absorption technique for remote monitoring of these molecules. The pressure and temperature dependence of the cross sections are described by and coefficients; these coefficients were calculated for the largest absorption cross sections for each molecule. The absorption cross sections of CH3OH and HCOOH at low pressures for all these CO2 lasers are also presented. These calculations are provided for design of new CO2-laser-pumped far-infrared lasers. 1. Introduction In this paper we report molecular absorption cross sections at CO2-laser emission frequencies for several selected gases of atmospheric relevance (M？=？NH3, C2H4, CO2, O3, NO2, PH3, HNO3, SF6, CH3OH, HCOOH, OCS, CH3CN, C2H6, SO2, and H2O). This information may be useful mainly in the differential absorption (Light Detection and Ranging) LIDAR technique for remote measurement of the gas species [1–8] and also may be used to monitor the CO2 content in fuel combustion products [9], remote sensing of gases in human breath [10], or multiphoton dissociation processes or to measure water vapor concentration and wind speed vector in the plume of volcano [11, 12]. Note that the LIDAR technique sometimes is used for remote sensing of some exotic gases, like, for example, chemical warfare [13]. In some cases (CH3OH and HCOOH) it also may be used in designing optically pumped FIR (far infrared=THz) lasers where CO2 laser is used as a source of a pump radiation [14]. Also, the absorption of CO2-laser radiation by a cell with a mixture of some of these gases is used in our lab for quick check and assignment of the CO2-laser lines. The focus of the present study is to predict absorption cross section in pure air at wavelengths of seven isotopic CO2 lasers: 12C16O2 (normal), 13C16O2, 12C18O2, 14C16O2, 14C18O2, 13C18O2, and 12C16O18O, which we hereafter denote as 26-, 36-, 28-, 46-, 48-, 38-, and 268-lasers. In the clear atmosphere, absorption at 9–11？μm is due primarily to water vapor and carbon dioxide. Since the fraction of CO2
References
[1]
C. Weitkamp, Lidar Range-Resolved Optical Remote Sencing of the Atmosphere, Springer Science and Business Media Inc., 2005.
[2]
B. I. Vasil'ev and O. M. Mannoun, “IR differential-absorption lidars for ecological monitoring of the environment,” Quantum Electronics, vol. 36, no. 9, pp. 801–820, 2006.
[3]
J. R. Quagliano, P. O. Stoutland, R. R. Petrin et al., “Quantitative chemical identification of four gases in remote infrared (9–11？μm) differential absorption lidar experiments,” Applied Optics, vol. 36, no. 9, pp. 1915–1927, 1997.
[4]
S. Lundqvist, C. O. Falt, U. Persson, B. Marthinsson, and S. T. Eng, “Air pollution monitoring with a Q-switched CO2-laser lidar using heterodyne detection,” Applied Optics, vol. 20, no. 14, pp. 2534–2538, 1981.
[5]
U. Persson, S. Lundqvist, B. Marthinsson, and S. T. Eng, “Computerautomated CO2-laser long-path absorption system for air quality monitoring in the working environment,” Applied Optics, vol. 23, no. 7, pp. 998–1002, 1984.
[6]
W. Schnell and G. Fischer, “Carbon dioxide laser absorption coefficients of various air pollutants,” Applied Optics, vol. 14, no. 9, pp. 2058–2059, 1975.
[7]
A. Mayer, J. Comera, H. Charpentier, and C. Jaussaud, “Absorption coefficients of various pollutant gases at CO2 laser wavelengths, application to the remote sensing of those pollutants: errata,” Applied Optics, vol. 17, no. 3, pp. 391–393, 1978.
[8]
A. Pal, C. D. Clark, M. Sigman, and D. K. Killinger, “Differential absorption lidar CO2 laser system for remote sensing of TATP related gases,” Applied Optics, vol. 48, no. 4, pp. B145–B150, 2009.
[9]
K. I. Arshinov, M. K. Arshinov, V. V. Nevdakh, M.-Y. Perrin, A. Soufiani, and V. V. Yasnov, “Accuracy in determination of the temperature and partial pressure of CO2 in CO2:N2:H2O:NO2 mixtures by multiple-frequency laser probing,” Journal of Applied Spectroscopy, vol. 74, no. 6, pp. 903–909, 2007.
[10]
M. Hamza, M. H. S. El-Ahl, and A. M. Hamza, “New laser system for sensitive remote sensing of ammonia in human breath,” in Proceedings of the Air Monitoring and Detection of Chemical and Biological Agents II, vol. 3855 of Proceedings of SPIE, pp. 28–33, September 1999.
[11]
L. Fiorani, F. Colao, and A. Palucci, “Measurement of Mount Etna plume by CO2-laser-based lidar,” Optics Letters, vol. 34, no. 6, pp. 800–802, 2009.
[12]
L. Fiorani, F. Colao, A. Palucci, D. Poreh, A. Aiuppa, and G. Giudice, “First-time lidar measurement of water vapor flux in a volcanic plume,” Optics Communications, vol. 284, no. 5, pp. 1295–1298, 2011.
[13]
P. P. Geiko and A. Tikhomirov, “Remote measurement of chemical warfare agents by differential absorption CO2 lidar,” Optical Memory and Neural Networks, vol. 20, no. 1, pp. 71–75, 2011.
[14]
E. M. Telles, H. Odashima, L. R. Zink, and K. M. Evenson, “Optically pumped FIR laser lines from CH3OH: new laser lines, frequency measurements, and assignments,” Journal of Molecular Spectroscopy, vol. 195, no. 2, pp. 360–366, 1999.
[15]
C. Bellecci, M. Francucci, P. Gaudio et al., “Application of a CO2 dial system for infrared detection of forest fire and reduction of false alarm,” Applied Physics B, vol. 87, no. 2, pp. 373–378, 2007.
[16]
P. Gaudio, M. Gelfusa, I. Lupelli et al., “First open field measurements with a portable CO2 lidar/dial system for early forest fires detection,” in Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing VII, September 2011.
[17]
N. Jacquinet-Husson, L. Crepeau, R. Armante et al., “The 2009 edition of the GEISA spectroscopic database,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 112, no. 15, pp. 2395–2445, 2011.
[18]
L. F. Chernogor and A. S. Rashkevich, “Results of en-route monitoring of the laser gas polluting impurities in the atmosphere,” Eastern European Journal of Enterprise Technologies, vol. 52, article 57, 1987.
[19]
K. Fox, “Strengths of the SF6 transitions pumped by a CO2 laser,” Optics Communications, vol. 19, no. 3, pp. 397–400, 1976.
[20]
J. L. Lyman, R. G. Anderson, R. A. Fisher, and B. J. Feldman, “Absorption of pulsed CO2-laser radiation by SF6 at 140？K,” Optics Letters, vol. 3, no. 6, pp. 238–240, 1978.
[21]
H. Kariminezhad, P. Parvin, F. Borna, and A. Bavali, “SF6 leak detection of high-voltage installations using TEA-CO2 laser-based DIAL,” Optics and Lasers in Engineering, vol. 48, no. 4, pp. 491–499, 2010.
[22]
U. Persson, B. Marthinsson, J. Johansson, and S. T. Eng, “Temperature and pressure dependence of NH3 and C2H4 absorption cross sections at CO2 laser wavelengths,” Applied Optics, vol. 19, no. 10, pp. 1711–1715, 1980.
[23]
J. N. Olsen, “Laser-initiated channels for ion transport: CO2-laser absorption and heating of NH3 and C2H4 gases,” Journal of Applied Physics, vol. 52, no. 5, pp. 3279–3285, 1981.
[24]
R. R. Patty, G. M. Russwurm, W. A. McClenny, and D. R. Morgan, “CO2 laser absorption coefficients for determining ambient levels of O3, NH3, and C2H4,” Applied Optics, vol. 13, no. 12, pp. 2850–2854, 1974.
[25]
A. P. Force, D. K. Killinger, W. E. DeFeo, and N. Menyuk, “Laser remote sensing of atmospheric ammonia using a CO2 lidar system,” Applied Optics, vol. 24, no. 17, pp. 2837–2841, 1985.
[26]
Y. Zhao, “Line-pair selections for remote sensing of atmospheric ammonia by use of a coherent CO2 differential absorption lidar system,” Applied Optics, vol. 39, no. 6, pp. 997–1007, 2000.
[27]
B. D. Green and J. I. Steinfeld, “Absorption coefficients for fourteen gases at CO2-laser frequencies,” Applied Optics, vol. 15, p. 1688, 1975.
[28]
L. T. Molina and W. B. Grant, “FTIR-spectrometer-determined absorption coefficients of seven hydrazine fuel gases—implications for laser remote sensing,” Applied Optics, vol. 23, no. 21, pp. 3893–3900, 1983.
[29]
N. Menyuk, D. K. Killinger, and W. E. DeFeo, “Laser remote sensing of hydrazine, MMH, and UDMH using a differential-absorption CO2 lidar,” Applied Optics, vol. 21, no. 12, pp. 2275–2286, 1982.
[30]
J. S. Ryan, M. H. Hubert, and R. A. Crane, “Water vapor absorption at isotopic CO2 laser wavelengths,” Applied Optics, vol. 22, no. 5, pp. 711–717, 1983.
[31]
H. Ahlberg, S. Lundqvist, and S. T. Eng, “Absorption coefficients of chlorine-dioxide 12C1802 laser wavelengths: applications to remote monitoring in the working environment,” Applied Optics, vol. 23, no. 17, pp. 2902–2905, 1984.
[32]
F. Allario and R. K. Seals Jr., “Measurements of NH3 absorption coefficients with a 13C16O2 laser,” Applied Optics, vol. 14, no. 9, pp. 2229–2233, 1975.
[33]
Z. Zelinger, I. Jancik, and P. Engst, “Measurement of the NH3, CCl2F2, CHClF2, CFCl3, and CClF3 absorption coefficients at isotopic 13C16O2 laser wavelengths by photoacoustic spectroscopy,” Applied Optics, vol. 31, p. 6974, 1992.
[34]
D. Pereira, A. Scalabrin, G. P. Galv？o, and K. M. Evenson, “13CD3OH and 12CD3OH optically pumped by a13CO2 laser: observations and assignments of FIR laser lines,” International Journal of Infrared and Millimeter Waves, vol. 13, no. 4, pp. 497–506, 1992.
[35]
L. F. L. Costa, J. C. S. Moraes, F. C. Cruz, R. C. Viscovini, and D. Pereira, “Infrared and far-infrared spectroscopy of 13CH3OH: teraHertz laser lines and assignments,” Journal of Molecular Spectroscopy, vol. 241, no. 2, pp. 151–154, 2007.
[36]
L. F. L. Costa, J. C. S. Moraes, F. C. Cruz, R. C. Viscovini, and D. Pereira, “CH3OH optically pumped by a 13CO2 laser: new laser lines and assignments,” Applied Physics B, vol. 86, no. 4, pp. 703–706, 2007.
[37]
R. C. Viscovini, J. C. S. Moraes, L. F. L. Costa, F. C. Cruz, and D. Pereira, “DCOOD optically pumped by a 13CO2 laser: new terahertz laser lines,” Applied Physics B, vol. 91, no. 3-4, pp. 517–520, 2008.
[38]
J. C. Petersen and G. Duxbury, “Observation and assignment of submillimetre laser lines from CH3OH pumped by isotopic CO2 lasers,” Applied Physics B, vol. 27, no. 1, pp. 19–25, 1982.
[39]
J. C. Petersen and G. Duxbury, “Submillimetre laser lines from CH3OH pumped by a13C18O2 pump laser: observations and assignments,” Applied Physics B, vol. 34, no. 1, pp. 17–21, 1984.
[40]
C. Freed, L. C. Bradley, and R. G. O'Donnell, “Absolute frequencies of lasing transitions in seven CO2 isotopic species,” IEEE Journal of Quantum Electronics, vol. 16, no. 11, pp. 1195–1206, 1980.
