Emission spectrum behavior of a dye random laser

We have shown experimentally that spectrum formation of dye based random laser (RL) is significantly affected by Raman scattering causing quasi-line spectrum under diffusive regime of photon propagation in the random medium. The Raman lines are observed against wide background. The lines arise only being overlapped with dye gain contour. Their intensities nonlinearly increase under pump increasing as power dependency with factor ~2.5. It has been shown the stimulated Raman amplification causes appearance of the lines in the RL spectrum. The appropriate condition for the amplification arises due to resonance between the waves of pumping and RL at stokes frequencies on the one hand and dye molecules vibration on the other.