Optical Nonlinearity Properties of Ag Nanofluid Measurements using a Single Beam Z-scan Technique

Nonlinear refractive index and nonlinear absorption of Ag nano-fluid prepared by γ-radiation method were investigated using a single beam Z-scan technique. Under a CW laser beam excitation operated at 532 nm with the power output of 40 mW, the Ag nano-fluid shows a large thermal- induced nonlinear refractive index and nonlinearity absorption. We measured the nonlinear refraction coefficient of silver nano-fluid for concentrations, 1.170 x 10 -3 and 5.297 x 10 -3 M. respectively. We found the nonlinear refractive index is in the order of 10 -8 cm 2 /W with the negative sign indicates the self-defocusing phenomenon. However for the Ag nano-fluid sample with 1.170 x 10 -3 M, the result shows that the nano-fluid sample has only a nonlinear refractive index property.