Fast imaging of the plume expansion produced by laser ablation of LiNbO3

Fast photography of the plume produced by laser ablation of LiNbO3 in vacuu m has been performed using an image intensified CCD (ICCD) camera in a time interval up to 2 mu s after the laser pulse. Two differently oriented sing le crystalline LiNbO3 targets were used. The results show that although the emission intensity of the laser-generated plume initially depends on the c rystalline orientation of the target, it reaches a stationary state after s everal minutes which is the same for both targets orientations. Under these stationary conditions, the angular distribution of the Li atoms is found t o be broader than that of Nb atoms. The observed less forward directed expa nsion of the Li species may explain the poor Zi content normally observed i n films grown by laser ablation of LiNbO3 in vacuum.