The effect of doping acid on the third-order nonlinearity of carboxymethyl cellulose by the Z-scan technique

Abstract The studies on the third-order nonlinear optical properties of carboxymethyl cellulose nanocomposite in the absence and presence of inorganic acid as a dopant was reported. The Z-scan technique was used to measure the nonlinear refraction n 2 , and absorption β , indexes and the third-order nonlinear susceptibility χ 3 . Characterization of this nanocomposite was performed by using scanning electron microscopy and Ultraviolet–Visible absorption spectroscopy in two different solvents; Dimethylformamide and N-Methylpyrrolidone. Additionally X-ray diffraction was used to study their crystal structure. The measured values of the nonlinear refraction of each sample in both of the solutions were in the order of 10 −9 m 2 /w and the corresponding third-order nonlinear susceptibilities were in the order 10 −4  esu.