Knowledge Bank

High temperature absorption spectra of an isotopically enriched sample of $CO2$ has been measured in the 4.3$\mu$m region using the Air Force Geophysics Laboratory (AFGL) high resolution interferometer. A maximum optical path difference of 75 cm was used, resulting in an unapodized spectral resolution of about $0.007cm-1$. Due to the difficulty in making positive identification of spectral lines in the dense experimental spectra, only those bands with a lower state vibrational term value than $1400cm-1$ for $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C16O2$ and the fundamental of $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C16O18O$ had previously been $identified1$. Additional bands of these two isotopes have now been identified in the experimental spectra. Vibration-rotation constants which predict the position of spectral lines of these bands with an estimated accuracy of $0.0004cm-1$ will be presented. $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$M.P. Esplin, R.J. Huppi and G.A. Vanasse, Appl. Opt. 21, 1681 (1982). This work was supported by the Air Force Office of Scientific Research.