Third-order nonlinear optical (NLO) properties of the synthesized conjugated organic molecules based on
carbazole derivatives were studied at different input intensities and wave lengths, by the Z-scan method and
using continuous wave (CW) lasers. The normalized transmittance results are explained by 5tting the data with
theoretical models of the open and close aperture Z-scan technique. Measurements demonstrated the in6uence of
saturation in absorption and thermal lensing effects on the nonlinear optical coef5cients and also indicate a
strong correlation between linear and nonlinear optical absorption. Also, photoacoustic behaviour and photoluminescence of the components were investigated which shows the high optical potential of these organic
molecules in different optical 5elds and devices. It was found that frequency spectra of photoacoustic signals
were the same for all derivatives, but with different amplitudes.