Investigation on the Optical Properties of Nonlinear Optical (NLO) Single Crystal: L-Valine zinc hydrochloride

The development and encroachment of high technology, from transportation, computation to information is based on the availability of materials in the form of single crystals. With progress in crystal growth technology and characterization, organic, inorganic, semiorganic and organometallic materials having attractive nonlinear optical (NLO) properties are being discovered at rapid rate. NLO materials possess several attractive properties such as high NLO coefficient, high laser damage threshold, wide transparency range, high mechanical strength and thermal stability, which make the materials suitable for second harmonic generation (SHG) and other NLO applications. Single crystals of L-Valine zinc hydrochloride were grown by the slow evaporation technique. The single crystal X-ray diffraction analysis reveals that the crystal belongs to the monoclinic system. The optical absorption spectrum reveals the transparency of the crystal in the entire visible region and the cut off wave length has been found to be 210 nm. The optical band gap is found to be 5.91 eV. Optical constants such as the band gap (Eg), refractive index (n), reflectance (R), extinction coefficient (K) and the real (εr) and imaginary (εi) components of the dielectric constant and electric susceptibility (χc) were determined from the UV-VISNIR absorption spectrum.