Role of parametric effects in generation of higher components of stimulated Raman scattering in gases

Numerical calculations were made of a resonant parametric interaction between the anti-Stokes component, the pump, and the first and second Stokes components of stimulated Raman scattering in a gas (four-wave model). A Raman converter utilizing hydrogen and deuterium was optimized. At pressures of 0.5–1 atm a three-color radiation with an angular divergence of 0.5 mrad was obtained. The maximum energy of the anti-Stokes component was 100 mJ (stimulated Raman scattering in H₂, conversion efficiency 6%) and 150 mJ (stimulated Raman scattering in D₂). The spatial coherence was high and this made it possible to record holograms of scattering objects at wavelengths of 0.43, 0.53, and 0.68 μ.