The synthesis of a new curcumin analogue dye via 3-chloro-2,4-pentanedion condensing with an aromatic aldehyde is considered. Following that, the synthesized compound is diagnosed utilizing spectroscopic methods, including FTIR, mass, ¹H NMR, and ¹³CNMR. The curcumin analogue geometric optimization and theoretical studies are conducted on thermodynamic properties using DFT. The B3LYP techniques, which are hybrid functional with a 6–311+G(d) as the basis set, are adopted to compute the HOMO, LUMO, and Mullikan atom charges of the studied compound. The curcumin analogue dye nonlinear optical (NLO) properties are examined under excitation with a 473 nm, low power, cw and TEM₀₀ mode laser beam. The index of nonlinear refraction (INLR) and coefficient of nonlinear absorption (CNLA) are estimated using diffraction patterns for the former and Z-scan for the latter. The INLR reaches a value as high as 6.86×10⁻¹¹ m²/W, while the CNLA reaches 2.23×10⁻³ cm/W. All-optical switching (AOS) is tested in the novel curcumin analogue dye using two methods: static AOS and dynamic AOS.