The potential applications for optical and optoelectronic devices of nanosized semiconductors confined in a dielectric material are well recognized in current scientific literature (1–5). In particular, composite materials formed by Si-based nanocrystals embedded in dielectric hosts are promising candidates for the fabrication of non-linear optical devices, but their development is still at an early stage. Here, we report results on nanocomposites (aerogels) obtained integrating laser synthesised Si-nanoparticles into a continuous silica phase by sol-gel processing. After annealing at different temperatures (300–500 °C), the produced materials were characterised by Raman scattering measurements and the sample homogeneity was checked by micro-Raman mapping. TEM analysis of the nanocomposites pointed out at the presence of agglomerated nanoparticles (100–200 nm average size) as confirmed by Dynamic Light Scattering (DLS) measurements on colloids prepared by dispersion of the as-produced powders in methanol. Preliminary results will be presented on the linear (visible luminescence) and non-linear (z-scan) optical characterisation of the samples.