Generation of picosecond YAG laser radiation and its efficient conversion to the visible and ultraviolet range in atomic barium vapor

Emission at wavelengths of 1.0615 and 1.074 μ from a self-mode-locked YAG:Nd³⁺ laser was observed at thresholds which were only 1.5 and 3.5 times higher than the threshold for the emission of radiation with λ = 1.064 μ. Efficient conversion (characterized by a quantum efficiency of ~ 15%) of the third harmonics of the radiations with λ = 1.064 and 1.0615 μ to the visible (590 nm) and ultraviolet (250 nm) ranges was achieved in atomic barium vapor. Electron stimulated Raman scattering due to a strongly forbidden transition in a system of Ba atoms was observed for the first time.