Fourier Transform Spectroscopy of OH and OD in the Infrared

We are making a thorough study of the Meinel bands of OH and OD radicals in the spectral region 1900 to 9000 cm−1. Three sources have been used, the ozone-hydrogen flame, the oxygen-acetylene flame, and the inductively coupled plasma (ICP). Differences in the spectra are immediately apparent, as shown in Figure 1. The ozone-hydrogen flame operates at low pressure, the lines are sharp, and the excitation is non-thermal. The oxygen-acetylene flame operates at atmospheric pressure and produces thermal excitation and broad lines. The ICP spectrum is similar to the oxygen-acetylene flame but with lines of intermediate sharpness.