Compression of high-power KrF laser pulse by backward Raman scattering using focused geometry

We are working on the generation of the high-power UV pulse by backward Raman pulse amplification. This report deals with the generation of the high-power backward first Stokes light using a simple focusing geometry. The high-power Stokes light, which grows from spontaneous scattered light in the focal region, can be obtained by focusing the high-energy KrF pump pulse into a Raman cell filled with methane gas. The intensity of the pump pulse increases significantly near the focus. This pulse produces a serious effect of the nonlinear refractive index. We mixed xenon gas into the Raman medium to compensate for this effect. As a result, a stable generation of the high-power single backward first Stokes light can be obtained.