Abstract:
A description is given of a universal laser spectroanalytic system which can be used to carry out separately or simultaneously several nonlinear spectroscopic investigations by methods including coherent anti-Stokes Raman scattering (CARS), photoacoustic Raman spectroscopy (PARS), etc. An automated system for data acquisition and spectrometer control is based on an IVK-2 measuring- computing unit. The results are reported of experiments carried out using the system: these revealed new physical effects, such as two-photon Raman saturation of vibrational-rotational transitions in molecules and a two-photon Raman optoacoustic effect. It is shown that the system can be used to study nonlinear optical susceptibilities of a dense plasma (formed by optical breakdown of neutral gases) and of polyatomic molecules with strongly excited vibrational levels.