Ultrabroad-bandwidth multifrequency Raman generation

We report on the modeling of transient stimulated rotational Raman scattering in H2 gas. We predict a multifrequency output, spanning a bandwidth greater than the pump frequency, that may be generated without any significant delay with respect to the pump pulses. The roles of dispersion and transiency are quantified. Multiple high Stokes and anti-Stokes orders are fre-quently observed in stimulated Raman scattering (SRS). Usually, higher orders are generated under phase-matched conditions and thus are at widely differing angles. This results in a multifrequency beam that is not focusable to a single spot. The much more interesting case is that in which higher orders are generated with a phase mismatch but are collinear. Such a beam may have application to laser fusion."2 Recently multiple orders of compa-rable amplitude spanning a broad bandwidth were generated with both H2 and N2 gas.3'4 Previously i