Hot Bands of Carbon Dioxide in the 15 Micron Region

The Air Force Geophysics Laboratory (AFGL) high resolution Michelson interferometer has been used to make measurement of the spectrum of CO2 in the 15 µm region. The infrared spectrum of a linear molecule like CO2 is composed of vibrational bands made up of many nearly equally spaced rotation lines. At high temperatures there is a great deal of overlapping of these bands. This overlapping causes the line density in the experimental spectrum to be very high. Since the band systems are spread over hundreds of wavenumbers, a Michelson interferometer with its capability of high resolution over wide spectral ranges is well suited to high temperature measurements.