Nonlinear optical properties of the tartrazine

Tartrazine is one of the food dyes with [Formula: see text] conjugated bond. The optical nonlinear properties of tartrazine in aqueous solution were investigated by Z-scan technique at the different input intensities of picosecond laser pulse. It was found that the tartrazine exhibits strong nonlinear optical behavior at the low input intensity. The experimental results show the nonlinear refractive indices reach the order of 10[Formula: see text] esu and their TPA cross sections are up to several hundreds of GM in the experimental condition. The strong optical nonlinearity perhaps allows them to be widely applied in the photoelectric and biological field.