Optical, thermal, mechanical, and dielectric properties of 5-Methyl L-Glutamate (5MLG) single crystals for NLO applications

Abstract

This study grew and thoroughly examined 5-methyl L-glutamate (5MLG) single crystals, potentially used in nonlinear optical (NLO) systems. The structural analysis suggests that the crystal belongs to the C₂ space group and has a monoclinic crystal structure. According to the optical analysis, the band gap is 4.69 eV, and the optical absorbance occurs at 264-nm. The Thermogravimetric analysis (TGA) was used to evaluate the thermal stability and breakdown profile of 5MLG. The results indicate that the material is thermally stable up to 189 °C. The stoke shift is calculated to be 3.92 eV. The microhardness tests proved that the crystal was mechanically stable up to 100 g, showing that it had strong physical properties suitable for device fabrication. The presence of all four forms of polarization is demonstrated by the strong dielectric constant at low frequencies, which is crucial for nonlinear applications. Second harmonic generation (SHG), which is 1.1 times more efficient than KDP, proved that the material could be used to double the frequency. Determining the material’s practical usage constraints requires this crucial step. Our study demonstrates that 5MLG’s superior optical, mechanical, and thermal properties make it a potential material for upcoming photonic technologies.