抄録
A supersonic free expansion of polyatomic molecules seeded in an inert carrier gas has been regarded as an excellent technique to produce the isolated and ultracold molecules which satisfy the requirements of an ideal spectroscopic sample. The cooling effects in the supersonic molecular beam are briefly summarized. An experiment on aniline with a simple pulsed supersonic nozzle combined with a pulsed tunable UV light source is described as an example of the fluorescence excitation spectroscopy. Recent progress on the optical spectroscopy of polyatomic molecules by use of the seeded supersonic free jets is reviewed from the photochemical and the photohysical point of view. The molecular structures and the dynamical behaviors in the excited states of the stable molecules and the van der Waals complexes are discussed.
