Synthesis of a novel organic chromophore (HCzN) for photophysical and nonlinear optical response showing its potential in photonic applications.

The present article demonstrates the photophysical and nonlinear optical studies of the chromophore 2,2'-(hexane-1,6-diylbis(9 H-carbazole-9,3-diyl))bis(ethene-1,1,2-tricarbonitrile (HCzN). The structure and the purity of the synthesized molecule have been confirmed via Infrared (IR) and Nuclear Magnetic Resonance (NMR) spectroscopies. Absorption and emission spectroscopies have been performed to understand the photophysical properties and we have enumerated the absorption coefficient (α0), refractive index (n0), optical bandgap (Eg), and optical conductivity (σ) for this chromophore. We have also explored the third-order nonlinear optical (NLO) characteristics of HCzN at the concentrations of 1, 2, 3, and 4 mM employing both closed and open-aperture Z-scan methods at 25 mW laser power. This chromophore evinces the self-defocusing and saturable absorption nature for closed and open aperture scans respectively. The calculated NLO parameters such as the coefficients of nonlinear refraction (n2) and nonlinear absorption (β) are found to be of the order of 10−6 cm2/W and 10−3 cm/W respectively with the nonlinear optical susceptibility (χ(3)), and hyperpolarizability (γ) of the order of 10−5 esu and 10–27 esu respectively. The magnitude of NLO parameters varies linearly concerning the concentration. The enhanced values of NLO parameters of chromophore HCzN shows its potential in photonic applications. [ABSTRACT FROM AUTHOR]