摘要： A third-order nonlinear optical crystal of lithium hydrogen maleate dihydrate (LHMD) is grown by the process of slow evaporation at room-temperature. The LHMD crystal system is orthorhombic and is a member of P space group. Using FTIR spectral investigation, the presence of main functional groups in LHMD crystal is identified. The optical behavior of the crystal is determined by UV-Visible spectroscopy. The bandgap energy of the LHMD crystal is calculated to be 3.4 eV. By Vickers microhardness measurements, the mechanical behavior has been assessed. The melting point of LHMD is determined by TG-DTA analysis. The defects present in the LHMD crystal are studied by dielectric loss and dielectric constant. SHG studies are performed for the LHMD crystal by Kurtz and Perry method. The third-order nonlinear characteristics of the LHMD crystal are analyzed by Z-scan technique. The laser damage threshold (LDT) study is carried out to verify the suitability of the crystal for laser applications.