Nonlinear Optical Response of Titania Nanoparticles Prepared by Pulsed Laser Ablation

Titania nanoparticles were prepared by a Nd:YAG pulsed laser ablation in distilled water. The nanoparticles were characterized by UV/visible spectroscopy, transmission electron microscopy (TEM) and single beam z-scan technique. With the help of UV/vis. spectrum the band gap of the nanoparticles was calculated about 3.7 eV for 0.75mj pulse energy. The average size of the nanoparticles was obtained about 14 nm from TEM images. In addition the size distribution of the nanoparticles ranged from 5 to 50 nm. The nonlinear index of refraction n2 and nonlinear absorption coefficient β were measured using closed and open aperture z-scan technique respectively using CW He-Ne laser at various intensities.