Second harmonic generation in Thiourea doped L-Threonine Non Linear Optical single crystal

Abstract

Non Linear Optics (NLO) is a new frontier area of science and technology that is to play a major role in the emerging technology of photonics, which is the technology of the 21st century. Non Linear Optical processes provide the key functions of frequency conversion and optical switching. These applications depend upon the various properties of the materials, such as transparency, birefringence, refractive index, dielectric constant, thermal, photochemical and chemical stability. Organic nonlinear materials are attracting a great deal of attention, as they have large optical susceptibilities, inherent ultra fast response times and high optical thresholds for laser power. In the present work Thiourea doped L-Threonine (TU doped LT) organic single crystal is grown at room temperature by slow evaporation technique. The lattice parameters and the functional groups are identified by single crystal XRD and FTIR studies respectively. The second harmonic generation (SHG) efficiency of a non linear optical material is a very important parameter from which we get an idea about the efficiency of the material in translating energy from fundamental beam to second harmonic beam. This is confirmed by Kurtz Perry powder technique using Q-switched Nd-YAG laser and the SHG efficiency of the grown crystal is found to be 0.47 times that of urea. This enhances the application of TU doped LT single crystal in non linear optical applications.