Low power Z–scan studies of Schiff base (E)-N'-(4-(dimethylamino) benzylidene) isonicotinohydrazide for nonlinear optical applications

Low power laser induced third-order nonlinear optical (TNLO) parameters of Schiff base molecule (E)-N'-(4-(dimethylamino)benzylidene) isonicotinohydrazide (ISB), is synthesized and characterised by UV-Visible, FT-IR, 1 H NMR, 13 C NMR and mass spectroscopy techniques. The effect of polar solvents on linear features and TNLO features of ISB are examined. TNLO properties of ISB are studied via low power Z–scan method, using a diode laser working at 650 nm wavelength. Self-defocusing, saturable absorption (SA) and reverse saturable absorption (RSA) based optical nonlinearities are observed. The order of nonlinear index of refraction (n 2 ) and nonlinear coefficient of absorption (β) of ISB is found to be10 −7 cm 2 /W and 10 −3 cm/W, respectively. The β of ISB has switchover from SA to RSA by increasing the solvent polarizability. Furthermore, the TNLO susceptibility (χ (3) ) of ISB increases with increase in solvent dipole moment. Due to its exceptional optical features; ISB serves as an ideal nonlinear optical material for photonics and optoelectronics applications.