Optically good quality single crystals of Thiourea L-alanine hydrochloride (TU-LAH) were grown by slow solvent evaporation technique. The grown TU-LAH crystals were confirmed by X-ray powder diffraction studies. Absorptions of these grown crystals were analysed using UV- Vis-NIR studies, and it was found that these crystals possess minimum absorption in the entire visible region. The TU-LAH crystals were characterized by Fourier transform Infrared (FT-IR) studies. Nonlinear optical studies of crystals were carried out and the second harmonic generation efficiency of the powdered sample was measured using Nd:YAG Q-switched laser with first harmonic output of 1064 nm and KDP was taken as the reference material. Scanning electron microscope studies and HR-SEM studies were carried out to show the presence of thiourea dopant in the grown crystal.

Keywords: NLO, Doped, XRD, FTIR, UV- Vis - NIR. HR-SEM,EDAX