PACS numbers: 61.72.Uj, 78.20.Ci, 78.30.FS, 78.55.Et LASER INDUCED NONLINEAR OPTICAL PROPERTIES OF ZINC OXIDE THIN FILM PREPARED BY SOL-GEL METHOD

Optical nonlinearities of spin coated ZnO thin film have been investigated by using single beam Z-Scan technique in the visible region. Xray diffraction shows that all films are oriented along the c-axis direction of the hexagonal crystal structure. The average optical transmittance of all films is higher than 80 %. The nonlinear optical parameters viz. nonlinear absorption coefficient (), nonlinear index of refraction (2), nonlinear susceptibility (3), have been estimated using nanosecond laser pulses of second harmonic of Nd:YAG Laser. The value of nonlinear absorption coefficient  is estimated to be greater than the already reported value. The films clearly exhibit a  ve value of nonlinear refraction at 532 nm which is attributed to the two photon absorption and free carrier absorption. The presence of RSA in ZnO thin films inferes that ZnO is a potential material for the development of optical limiter.