The PhD dissertation is organized in two parts. In the first part, we present an experimental study of stimulated Raman scattering in a silicon-on-insulator (SOI) nanowire. We demonstrate that the Raman amplification of a narrow-band Stokes wave experiences a saturation effect for high pump intensities because of self phase modulation of the pump beam. Moreover, an analytical model is presented that describes the experimental results remarkably well. The model furthermore provides an estimation of the Raman gain coefficient γR of silicon. The second part is devoted to the experimental study of stimulated Raman scattering in a doubly resonant planar GaAs microcavity. The nonlinear measurements clearly show some totally unexpected results. We experimentally demonstrate that the relaxation of the electrons in the conduction band of GaAs is significantly modified through the interaction with coherently excited Raman phonons.