Key aspects of l-threoninium picrate single crystal: an excellent organic nonlinear optical material with a high laser-induced damage threshold

Abstract

Recent trends focuses on the usage of nonlinear optical materials owing to their increasing demand in frontier areas of optical communication and switching applications. In the present work single crystal of L-threoninium picrate, an excellent material for nonlinear optical applications was grown using conventional slow evaporation solution technique to meet the increasing demand of photonics industry. The lattice parameters of the grown crystal were analysed by using powder X-ray diffraction, and it was found that it crystallised in monoclinic system with space group P2₁. The strain in the lattice of the grown crystal was calculated using Hall–Williamson relation. Crystalline perfection of the grown crystal was assessed using high resolution X-ray diffraction technique and observed that quality of crystal was fairly good. Optical transmission analysis and band gap evaluation were performed using UV-Vis spectroscopy. Laser damage threshold value for the crystal was also measured and was found to be higher than most of reported organic single crystals. Optical homogeneity of the crystal and birefringence was evaluated using modified channel spectrum method. Thermal behaviour of the grown specimen was examined by using photopyroelectric technique. Further its various mechanical properties, such as hardness, stiffness, young's modulus, were measured using nanoindentation technique.