Growth and Characterization of Nonlinear Optical (NLO) organic, inorganic and semiorganic single crystals

The recently started R&D activity of growth and characterization of NLO single crystals has been continued in view of (i) growing good quality crystals (ii) growing big size crystals suitable for device applications related to photonics, (iii) to enhance the efficiency of second harmonic generation (SHG) by using different dopants and functional groups, (iv) to search new NLO materials and grow their single crystals, (v) to evaluate their crystalline perfection by high-resolution XRD and (vi) other studies like powder XRD, FTIR, UV-Vis. etc. In this endeavor and with the help of various collaborators working in this upcoming area we have achieved several important R&D results leading to twenty one articles in leading SCI journals and one article in non SCI journal. Some of these important results are briefly described below.

Very recently we have grown and characterized some organic (Benzimidazole), inorganic (ADP) and semiorganic (ZTS) crystals doped with non NLO like KCl, Mn, Oxalic acid and NLO like urea and N-methyl urea. Due to these dopants, considerable enhancement in SHG efficiency was observed.

DAST crystal which is one of the high nonlinearity (141 times than that of urea) materials among all the ever known NLO single crystals grown by slope nucleation technique has been characterized. Growth and Characterization of semiorganic ZTC, a NLO single crystal grown by SEST and unidirectional Sankaranarayanan-Ramasamy (SR) methods have been carried out. Crystals up to 12 mm dia and 40 mm length have been grown. Its crystalline perfection and dielectric properties have been assessed.

Organic NLO single crystal of hippuric acid has been grown and characterized by unidirectional SR method. Its relative nonlinear optical efficiency is 1.54 times better than that of KDP.

Undoped, Mg doped and Mg, Nd codoped LiNbO3 single crystals grown by CZ method (at RRCAT, Indore) were characterized by HRXRD and found better perfection & optical properties due to doping.

Variety of new NLO crystals like Ammonium malate, glycine phosphate, DMAPNP, L-Tartaric acid, cadmium mercury thiocyanate, zinc cadmium thiocyanate etc. have been grown and characterized.