Thermally induced optical nonlinearity and optical power limiting action of 2,4,5-trimethoxy-4′-nitrochalcone under CW laser regime

In the present work, we report the results of thermally induced third-order nonlinear optical (NLO) properties of 2,4,5-trimethoxy-4′-nitrochalcone (abbreviated as 2,4,5TMNC) investigated by Z-scan technique using continuous wave (CW) Argon ion laser at a wavelength of 488nm with adjusted power ranging from 2.5mW to 20mW. The experiments were performed by varying the concentration of the molecules in solution. The sample demonstrated strong reverse saturable absorption (RSA) and self-defocusing effect (negative nonlinear refractive index). The estimated values of the NLO absorption coefficient (β), nonlinear refraction (n2) and absolute nonlinear susceptibility χ(3) are found to be of the order of 10−5m/W, 10−11m2/W and 10−5esu, respectively. The magnitude of the nonlinear absorption coefficient (β) was found to increase with concentration. The linear absorption spectrum of 2,4,5TMNC was measured using UV–Vis–NIR spectrometer. The optical band gap (Eg) value of title chalcone is obtained from the tauc’s p...