Azo-β-diketone compound is prepared via coupling reaction of dizonium salt of sulfanilamide with acetylacetone. The compound is characterized by FTIR, Mass and 1H NMR spectrocopies. The optimization of synthesized azo-β-diketone is carried out using B3LYP method 6-31G (d,p) basis sets. Nonlinear optical properties of synthesized azo-β-diketone is investigated via some quantum chemical descriptors calculation using DFT/B3LYP method with 6‐31G(d,p) basis set. The UV–vis spectrum of the synthesized azo-β-diketone is also calculated using TD-DFT with same optimization method and level. The nonlinear index of refraction of the azo-β-diketone at 473 nm is calculated using the spatial self-phase modulation and Z-scan techniques where as high as 3.259 × 10−7 cm2/W is obtained due to the first technique and 2.4 × 10−8 cm2/W due to the second technique. The compound optical limiting property is tested at the same wavelength with limiting threshold of 12 mW is obtained. The diffraction ring patterns are theoretically simulated based on the Fresnel-
Kirchhoff diffraction integral with results agree well with experimental findings.
