Diode laser spectroscopy of CO2 at 790 nm

Absorption lines of 12C^16O_2 have been examined by using a tunable diode laser spectrometer in the region around 12670cm^-1 (790nm). The spectrometer sources are commercially available double heterostructure InGaAlAs tunable diode lasers (TDLs) operating in the "free-running" mode, which allowed the detection of the line positions within 0.01cm^-1. The observed carbon dioxide absorption lines belong to the combination overtone 2v2+5v3 ro-vibrational band with intensities ranging around 10^-28cm/molecule.