Highly sensitive absorption spectroscopy of carbon dioxide by ICLAS-VeCSEL between 8800 and 9530 cm-1

The absorption spectrum of carbon dioxide has been studied between 8800 and 9530 cm(-1) by intracavity laser absorption spectroscopy based on a vertical external cavity surface emitting lasers (VeCSEL). Previous laboratory spectra at high resolution were nearly absent in the considered spectral region. Experiments were carried with natural carbon dioxide and with C-13 enriched carbon dioxide leading to the determination of the rovibrational parameters of a total of 15 very weak vibrational transitions, including two bands of the (OCO)-O-16-C-13-O-18 isotopologue. The observed transitions are assigned to components of the 2v(1), + 3v(3) triad and of the much weaker 5v(1) + v(3) hexad. Our measured line positions are found in excellent agreement with the predictions of the effective Hamiltonians developed for (OO2)-O-12-O-16, and (CO2)-C-13-O-16 but significant deviations were evidenced for the (OCO)-O-16-C-13-O-18 minor isotopologue. The relative band intensities within each polyad are also discussed on the basis of the effective Hamiltonian model. (c) 2005 Elsevier Inc. All rights reserved.