High resolution Doppler-free laser techniques are used in beam experiments to improve
the spectroscopic description of complex diatomic molecules. The case of TiO is
considered here for its implication in reaction dynamics studies and its interest in
Astrophysics. Two absorption bands in the visible have been analyzed:
B3Π−X3 Δ(1−0) and c1Φ−a1 Δ(0−0). Owing to accurate wavenumber measurements,
it has been possible to extend the analysis to high rotational quantum numbers
and to carry out detailed spectroscopic calculations. They show that a careful revisiting
of the TiO electronic structure is necessary.