[OPTICAL REVIEW Vol. 4, No. 3 (1997) 362-365]

Line Shapes in the R-Branch of the 5.3 μm NO Band

Mikihiko HIRONO* and Kenji ICHIKAWA

Department of Electrical and Electronic Engineering, Faculty of Engineering, Niigata University, Niigata, 950-21 Japan

(Received December 3, 1996; Accepted March 18, 1997)

The shape of the spectral lines in the 5.3 μm fundamental band of NO perturbed by N2 was studied by means of an infrared spectrometer. Sub-Lorentzian line profile was observed in the wing of the R-branch. These deviations from the Lorentz shape can be mainly interpreted in terms of line mixing. To calculate line-coupling coefficients, the exponential gap law and the statistical exponential power gap law (SEPG) were used. In the case of the SEPG model the degeneracy factor dependence on the inelastic rate is also discussed. The influence of the slit width on the observed band-correction function was found to be small in the R-branch wing of NO.

Key words : line shape, line mixing, line coupling, infrared absorption, infrared spectra