Laser optical spectroscopy and Raman spectrometer
Laser-induced emission spectroscopy for the authentication of wines

Molecular spectroscopy is based on the phenomenon of light-matter interaction. Light radiation carries energy (the energy of a photon is inversely proportional to its wavelength) which can be absorbed by the irradiated material. These mechanisms are described schematically in figure 1. When the photon has an energy corresponding to the energy difference between the fundamental quantum state of a molecule and one of its excited quantum states, a resonance phenomenon occurs, with a transition from the fundamental to the excited state. For low-energy photons, i.e. for the micrometer wavelengths of infrared radiation, the quantum levels considered correspond to molecular vibrations.