TUNABLE LASERS AT THE LASER SPECTROSCOPY GROUP: SHORT FORM HISTORY FROM THE BEGINNINGS TO DATE

A brief definition of tunable lasers is given. Detailed results on tunable dye lasers and on tunable diode lasers are presented, as obtained from 1975 - to date. First, the nitrogen pulsed laser was presented which is used to pump dye lasers: operation, main constructive elements, pulse time shapes and structure and beam power characteristics. Nitrogen lasers designed and engineered by the group in the years 70's - 90's are also introduced. Secondly, results on dye lasers are presented: operation, laser cavities/optical resonators, spectral characteristics of the tunable laser radiation (tunability in the visible and near UV), time structure of the dye laser pulses, beam power evolution function of working parameters. The dye lasers engineered in-house in the years 70's - 90's are introduced, as well. The main applications developed using dye/tunable lasers are presented for two main fields: pollution control and biomedicine. Finally, tunable semiconductor lasers studies are introduced: tunable diode laser systems (emitting in the visible and NIR) mounted in Littrow extended cavities, beat note detection to measure emitted wavelengths stabilities for two tunable diode laser systems and the investigation of chaotic dynamics of an external-cavity semiconductor laser emitting in the regime of low-frequency fluctuations.