Line strengths and self-broadening coefficients of carbon dioxide isotopologues (13CO2 and 18O12C16O) near 2.04 μm for the in situ laser sensing of the Martian atmosphere

A diode laser spectrometer was used in the laboratory to study 13CO2 and 18O12C16O line intensities and self-broadening coefficients near 2.04 μm. The spectral region ranging from 4896 to 4903 cm−1, which is suitable for in situ laser sensing of both isotopologues in the lower Martian atmosphere, was investigated using a distributed feedback GaInSb diode laser. Five lines of the (2 00 1)II←(0 0 0) band of 13CO2 and seven lines of the (2 00 1)II←(0 0 0) band of 18O12C16O were carefully revisited. The measured intensities and self-broadening coefficients were thoroughly compared with relevant molecular databases.