Recently, Graphite Oxide (GO), one of the main precursors of graphene based materials, has attracted tremendous attention and research interest be-cause of its exceptional physical properties and enormous amount of applications in optoelectronics, bio devices and nonlinear optics.

We synthesized GO coated thin films for various thicknesses by spin coating technique and studied its structural, linear and nonlinear absorption properties.

Though several works of GO has been done in nonlinear optics, the effect of thickness on nonlinear absorption property of GO films was found for the first time during this study.

Open aperture Z Scan technique is used to study the nonlinear absorption characteristics of the GO thin films and estimated nonlinear absorption coefficient and saturation intensity also.

We observed that the synthesized GO thin films showed saturable absorption behavior and explore its applications in Q-switched mode locking laser systems.