Improvement of spectroscopic data of CO2 in the 2.3 µm window

This manuscript is devoted to an analysis of highly sensitive absorption spectra of natural carbon dioxide and oxygen-18 enriched carbon dioxide at temperature 296 K and pressure 100 Torr and 47 Torr. The spectra have been recorded in Cavity Ring Down Spectrometer with Vertical-External-Cavity Surface Emitting Laser (VECSEL-CRDS) in the spectral range between 4295 and 4380 cm¿1. In this region, the absorption of carbon dioxide is very weak what makes it interesting for astronomical research, especially for studying the atmosphere of Venus, which consists of about 96.5% of carbon dioxide. The knowledge of carbon dioxide absorption in this region provides to better analysis of thermal radiation emitted by Venus to space, so to a better spectral analysis of deep Venus atmosphere.