Abstract

Infrared laser absorption techniques have been employed to measure absolute transition moments for several radical species by using a variety of techniques. For the OH radical, high precision relative transition strengths have been measured with a color center laser and used to determine the OH dipole moment function. The dipole moment function provides absolute transition strengths for Δv = 1–3 transitions with v″ < 9. This information is essential for quantitative modelling of the OH Meinel night glow. The infrared band strengths for all three fundamental vibrations of the HO₂ radical have been directly measured by using tunable infrared diode laser absorption. The HO₂ radicals were prepared with a known column density by reacting a known quantity of F atoms with excess H₂O₂. These band strengths will be used to measure HO₂ radical concentrations in the troposphere. Band strengths for the BF, CF₂, and CH₃ radicals have also been obtained using tunable diode laser absorption. These species' concentrations were quantified by by using various optical and chemical techniques. The experimental infrared transition strengths discussed above will be compared with published theoretical transition strengths obtained by using several techniques.

© 1992 Optical Society of America