Theoretical insight on the optical centred electrical properties of guanidinium isophthalate NLO crystal for electro-optic Q switches.

Guanidinium isophthalate single crystals with dimensions 16 × 4 x 2 mm3 were prepared by the low temperature solvent evaporation method and growth kinetics with interfacial tension was discussed to bring out the growth parameters of guanidinium isophthalate single crystals. The harvested single crystals were utilized for various characterization studies like powder X-ray diffraction, optical transmission, photoluminescence, laser damage study and optical limiting studies. The visualization of varying potential regions on the surfaces to quantify short contacts were generated by Hirshfeld surface analysis. 2D fingerprint plots were analyzed, in which H ….H contact was found to be the most significant with 54.1%. Growth kinetics of the crystalline material was studied to reveal the nucleation process. Crystal samples prepared with reference to the solubility data were found to be free of inclusions and cracks and had maximum transmittance in the complete visible region. The electronic disorder of the crystal sample was reported in the form of Urbach energy. The PL spectra with the emission intensity provide the emission characteristic of the title compound. The major fundamental optical limit for a crystal material is experimentally measured and presented in the picosecond regime. Thus the present work contributes to the understanding of growth, structural, optical and electronic characteristics of the title guanidinium isophthalate single crystals for the fabrication of electro-optic devices in photonic industry.

The exploration of the crystal nucleation parameters and physico-chemical analysis of a single crystal: 2-amino-4,6-dimethoxypyrimidinium hydrogen (2R,3R)-tartrate 2-amino-4,6-dimethoxypyrimidine.

This paper discusses the structural orientations and the physico-chemical properties of a single crystal of 2-amino-4,6-dimethoxypyrimidinium hydrogen (2R,3R)-tartrate 2-amino-4,6-dimethoxypyrimidine (2ADT). The experimental investigation of the properties of the compound improves the potential for the utilization of the crystalline compound in the fabrication of optical limiting and nonlinear optical devices. For the growth process, an organic nonlinear optical crystal of 2ADT is synthesized conventionally at varying molar concentrations to achieve an excellent yield. The structural orientations and refinements of the compound are identified and discussed with reference to a single crystal X-ray diffraction study and its supporting computations. The results of the experimental analysis via UV-vis-NIR spectrometry and a z-scan setup with a laser beam source are used in an in-depth discussion on the linear and nonlinear optical properties of the crystal together with its damage threshold induced by a Nd:YAG laser beam at 1064 nm. With optical transparency of 55% in the entire visible region, a lower cut-off wavelength at 228 nm, and a bandgap at 5.2 eV, the crystal was demonstrated to be suitable for use in optical device fabrication. The thermogravimetrically assessed thermal stability of 2ADT was examined up to 147 °C. In addition, the thermodynamic parameters responsible for activation reactions are also discussed because these give information about the material's thermal behavior. An optical limiting study revealed that the transmitted output power increases linearly with the input power at about 1.89 mW cm-2.