Stimulated Raman scattering in hydrogen pumped with a tunable, high power, narrow linewidth alexandrite laser

The conversion efficiencies and the linewidth of the Stokes components which result from stimulated Raman scattering in hydrogen gas pumped with a high power alexandrite laser have been studied. Measurements of the Stokes components under varying conditions reveal that there is no effect on the conversion efficiency by the narrowing of the pump linewidth and that the linewidth of the first Stokes component is broader than the expected linewidth of the injection seeded pump. Modelling of the conversion from the pump to the Stokes components shows a strong dependence of this conversion on a specific, resonant four wave mixing process. (author)