Optics and Photonics Society of Iran

In this paper, laser induced optical breakdown in colloidal Al2O3 and TiO2 nanoparticles was studied by using pump- probe beam technique. A Nd:YAG laser beam (operating at 1064 nm with pulse duration ~10 ns) was split in two and used as pump and probe beams in this experiment. The time varying transmission of the probe beam through the plasma was measured during the breakdown process. The results show that, the plasma transmissivity reduces with pump beam intensity. According to these results, the transmission of TiO2 nanoparticles plasma is higher than that of Al2O3. The results also show that, with respect to Al2O3, the plasma electron density in TiO2 colloid increases with a higher rate.