Exploring the nonlinear optical features of organic dye using Z-scan and DFT method

This is the authors' abstract. We don't add key points for this paper.

This paper reports the third-order nonlinear optical (NLO) features of organic dye namely, Safranin O dye dissolved in polar solvents including, ethanol, methanol, acetone, 1-propanol, DMF, and DMSO using Z-scan and DFT methods. Z-scan technique is employed to study the nonlinear refractive index and nonlinear absorption coefficient of the dye measured form closed and open aperture techniques, respectively. The results are revealed that the nonlinear refractive index is originated from self-defocusing, whereas saturable and reverse saturable absorption are the mechanisms behind nonlinear absorption coefficient of Safranin O dye in all solvents. Safranin O dye exhibited pronounced NLO behavior, with its DMSO solution presenting higher optical susceptibility. Third-order NLO susceptibility of the sample is measured to be the order of 10−7 esu. Geometry optimization followed by determination of NLO properties, including linear polarizability (α), first-order hyperpolarizability (β), and second-order hyperpolarizability (γ), of Safranin O dye is computed using DFT calculations in different solvent environments such as ethanol, methanol, acetone, 1-propanol, DMF, and DMSO. These theoretical predictions, aligned with experimental observations, provide valuable insights into the dye’s potential for advanced NLO applications.