Investigation of second- and third-order nonlinear optical properties of 4-picolinium glutamate single crystal for laser applications

The 4-Picolinium glutamate (4PG), a new organic nonlinear optical material, was produced, and slow evaporation was used to generate bulk crystals from aqueous solution. The synthetic material has an orthorhombic crystal system and a noncentrosymmetric structure with the P2₁2₁2₁ space group. In order to determine the functional groups of the formed crystal, an FT-IR analysis was done. The title compound’s UV–visible spectrum study reveals 82% transmittance with a lower cutoff wavelength of 250 nm and the material’s optical bandgap energy was determined to be 4 eV. The green fluorescence emission was identified by the 4PG crystals’ greatest intensity peak detection at 540 nm. Vicker’s microhardness testing and TG/DTA were used to examine the mechanical characteristics and thermal behavior of the produced crystals. Furthermore, dielectric measurements of the crystals at various frequencies were performed. The second harmonic generator’s Kurtz powder approach was verified and found to be 2.1 times more effective than KDP. The 4PG crystals’ laser usefulness limitation was stated using laser beam-irradiated LDT analysis. Using the Z-scan method, the optical characteristics of 4PG crystals were measured. These studies demonstrated that 4PG crystals could be valuable in nonlinear optical applications.