Abstract
Rayleigh scattering is the dominating stimulated scattering process when the absorption coefficient of the medium exceeds a critical value αcr. It is found that the transient gain of Rayleigh scattering is important for the competition with stimulated Brillouin scattering. The initial slope- not the peak power- of the incident laser pulse determines the value of αcr. Our findings are in full agreement with theoretical investigations.