To deposit cryolite thin films with a composition close to the correct stoichiometry on a silicon substrate, a Direst Pulsed Laser Deposition (DPLD) set-up and a Crossed Beam Pulsed Laser Deposition (CBPLD) set-up have been used. In the case of CBPLD two targets are simultaneously ablated and the two ablation plumes are crossing at 15 min from the targets. With the two different set-up thin films present a composition close to the correct stoichiometry (Na3AlF6). The surface of thin films deposited by DPLD shows a very high droplets density. At the opposite the CBPLD allows to decrease dramatically this density. Furthermore fast CCD-photographs of the plasmas have been used to study plumes expansion with the two different set-up. With the CBPLD one, the two plasmas interaction has been studied and their expansions have been compared with the one observed when only one target is ablated. The trajectories redistribution of the ablated species due to the collision of the two plasma clouds is clearly visible. (C) 1999 Elsevier Science B.V. All rights reserved.