Long-pulse N2 uv laser from a N2-CF4 mixture

Using a long-duration transverse discharge (300 ns) preionized by a short-pulse electron-beam gun (10 ns), laser emission has been obtained in the second positive system of nitrogen at λ=3371 Å in nitrogen alone and at λ=3577 Å in a N2-CF4 mixture. In the latter mixture, the laser emission lasts for 70 ns which is much longer than the radiative lifetime of the upper laser level C 3Πu(τF=40 ns). We think that the blottleneck of the terminal laser level is avoided thanks to the vibrational deactivation of the nitrogen B 3Πg state due to the irreversible transfer of vibrational energy of N2 to CF4 during collisions.