Reduced Brillouin scattering from multilineCO2laser interaction with a plasma

Experimental verification of reduced stimulated Brillouin scattering (SBS) is reported for multiline ${\mathrm{CO}}_2$ laser radiation interacting with high-density plasma. For long-pulse (40-nsec) irradiation SBS was observed to decrease from 15% to a negligible level when the spectrum of the incident laser pulse was changed from 1 to 2 or more well-separated frequencies. Results for both long- and short-pulse multiline laser conditions are in general accord with the expected behavior for varying $\frac{\Delta \omega }{{\gamma }_0}$, where $\Delta \omega$ is the frequency separation and ${\gamma }_0$ is the homogeneous growth rate.