Temperature dependence of intensities and widths of N2-broadened lines in the 15 μm CO2 band from tunable laser measurements

Abstract Intensities and nitrogen-broadened widths of several low-J lines in the Q-branch of the 15 μm band of CO2 have been determined over the temperature range 200–300 K. Measurements were made with a tunable infra-red diode laser spectrometer having a spectral resolution ∼ 10-4 cm-1. Measured intensities are uniformly about 7% lower than available calculations which were based on previous measurements of band intensity. Measured line widths are higher than available calculations and generally followed the relation b L 0 (T)=b L 0 (T 0 )(T 0 |T) n with n = 0.74 (standard deviation 0.08).

[1]  S. R. Drayson.  Atmospheric transmission in the CO(2) bands between 12 micro and 18 micro. , 1966, Applied optics.

[2]  Ellis E. Whiting,et al.  An empirical approximation to the Voigt profile , 1968 .

[3]  A. P. Williams,et al.  Integrated absorption of a spectral line with the Voigt profile , 1974 .

[4]  Sunil Sarangi,et al.  Measurements of intensities and nitrogen-broadened linewidths in the CO fundamental at low temperatures☆ , 1975 .

[5]  T. K. Mccubbin,et al.  The Temperature Dependence of the Self-Broadened Half-Width of the P-20 Line in the 001-100 Band of CO(2). , 1970, Applied optics.

[6]  S. R. Drayson.  A listing of wavenumbers and intensities of carbon dioxide absorption lines between 12 and 20 micrometers , 1973 .

[7]  K. Rao,et al.  Calibration of the absorption spectra at 14-15 microm obtained with a tunable diode laser. , 1976, Applied optics.

[8]  J. F. Butler,et al.  Measurements of the widths and strengths of low-J lines of the v2Q branch of CO2 , 1975 .

[9]  R. Nordstrom,et al.  Accuracy of the AFCRL atmospheric absorption line parameters compilation in the 10-microm atmospheric window. , 1976, Applied optics.

[10]  J. J. Olivero,et al.  Empirical fits to the Voigt line width: A brief review , 1977 .

[11]  H. Fleming,et al.  Effect of CO2 line width on 15 μm atmospheric emission , 1977 .

[12]  Masayuki Tanaka,et al.  Estimation of rotational line widths of carbon dioxide bands , 1969 .

[13]  J. F. Butler,et al.  Tunable Diode Laser High Resolution Spectroscopic Measurements of the nu(2) Vibration of Carbon Dioxide. , 1975, Applied optics.

[14]  Dudley A. Williams,et al.  Broadening of Infrared Absorption Lines at Reduced Temperatures: Carbon Dioxide† , 1972 .