Pumping a KrF excimer laser by a laser discharge induced by an IR laser beam

The possibility of pumping an excimer laser using a F₂–Kr–He mixture by a pulse of IR laser light through the development of a laser discharge in the active medium is analyzed. Numerical calculations have been carried out for the mixtures F₂:Kr:He = 3:75:1500 and 4:200:1500 torr pumped by laser pulses with wavelengths of 2.8 and 10.6 μm and pulse lengths of 20 – 150 ns. The transmission of the pump pulse through the F₂–Kr–He medium is studied. The absorption of the IR laser light by the electrons of the laser-discharge plasma produced by this light is taken into account. When IR light with a peak intensity on the order of 10 (λ = 2.8 μm) or 1 GW/cm² (λ = 10.6 μm) at the entrance to the laser medium is focused by an optical system with a focal length of 1–30 m, a KrF laser can be pumped with an efficiency ~5%.