High-efficiency Raman frequency conversion into blue-green region

A long pulse one Joule excimer laser was used as a pumping source for stimulated Raman scattering in lead vapour and hydrogen. High efficiency Raman frequency conversion into blue-green region was obtained . A decrement of Raman conversion efficiency at high repetition rate was observed in a sealed Raman cell. A hydrogen gas circulating system was designed with gas pressure up to 50 Atm,it can be operated at high repetition rate without decrement of Raman conversion efficiency.