A Schiff base was synthesized via a slow evaporation approach using the condensation reaction of substituted aniline and 2-hydroxy-1-naphthaldehyde. Single Crystal X-Ray Diffraction Analysis, Fourier Transform Infrared Spectroscopy, UV-Visible Spectroscopy, 1H NMR Spectroscopy, and 13C NMR Spectroscopy have all been used to identify it. The crystal space group is explained through crystallography. The structure of crystal was first solved using direct approach, later it was improved using a full-matrix least square strategy. The hydroxyl group and imine are connected by a powerful intramolecular H-bond (N-H·····O) in the crystal structure. The blue color emission is observed for E4CMN in emission spectrum. Assessing Hirshfeld surface was employed to look at supramolecular interactions. For evaluating the thermal behavior of crystals, thermal analysis (TG-DTA) was applied. The compound's surface morphology under the scanning electron microscope (SEM). Using the DFT basis set (B3LYP/6–311 ++G(d,p)), the energy gap (EHOMO, ELUMO), reactivity parameters and Mulliken charges, polarizability(α0), and hyperpolarizability(β0) were determined. Using quantum computations techniques NCI-RDG scatter diagram and scatter graph was obtained and DFT studies, Topological ELF along with LOL parameters are further characterization of E4CMN crystal. The Using a Nd: YAG laser, an open-aperture method of Z-scan analysis was employed to compute NLO absorption of third-order nonlinear optical properties. Nd: YAG laser (532 nm, 10 Hz, 9 ns) with a lowered onset limiting threshold could find that you are a suitable choice for constructing laser security measures in the nanosecond green stimulation region.