Temperature and pressure dependences of absorption in the narrow R₆₆-R₆₈ window of the ¹²C¹⁶O₂ v₃-band

Diode-laser measurements of absorption by CO₂-N₂ mixtures in the trough between the R₆₆ and R₆₈ lines of the ¹²C¹⁶O₂ v₃-band are presented. Experiments have been performed in the 1.0-7.0 atm pressure range at temperatures of 296 and 370 K. The measured absorption is very different from that predicted by the addition of Lorentzian contributions. Theoretical calculations accounting for line-overlapping based on a fitting law are presented. Although the effects of line-overlapping are slightly underestimated, the agreement between experiments and calculations is quite good, for both the pressure and temperature dependences.