Abstract

Stimulated Raman scattering in the VUV spectral region is of much interest for nonlinear optics, because of the strong dispersion of the refractive indices, as well as for generation of coherent radiation. We have investigated stimulated Raman scattering in molecular hydrogen (and deuterium) gases with an argon excimer laser that produces pulsed high-power coherent light tunable around 126 nm. Since the Lyman-α transition lies in this spectral region, the resonance effect was expected and the intense first and second Stokes lines were actually observed for narrowband pulsed-laser pumping with a 0.3-nm bandwidth. However, no anti-Stokes lines appeared. The relative intensities of the respective Raman lines were found to depend largely on the bandwidth of the laser. By using the broadband laser oscillation of 1 nm, in addition to the intense first Stokes line the second Stokes and anti-Stokes lines were observed. These differences of the relative intensities come from the dispersive properties of the gas. For these experiments laser pulses with a 4-6-ns pulse width were used. The transient effect is discussed.

© 1986 Optical Society of America