High sensitivity CRDS of CO 2 in the 1.74 µm transparency window. A validation test for the spectroscopic databases

•High sensitivity CRDS of CO2 in the 1.74 µm transparency window of interest for Venus.•More than 1100 transitions assigned to 26 bands of six isotopologues.•Very weak lines with intensity value as low as 10−30 cm/molecule are detected.•The observations validate ab initio intensity values.•Some deficiencies are evidenced in the HITRAN2016 list and analyzed.