Growth of bulk single crystals of urea for photonic applications

We report the growth of technologically important urea crystals of record size (48 x 16 x 8 mm(3)) by doping sulfuric acid and employing slow evaporation technique. The grown crystal was identified by single crystal X-Ray diffraction and FTIR spectral analysis. Optical properties of the grown crystal were analyzed by UV-Vis spectrum and the presence of H2SO4 was confirmed by EDAX analysis. Thermogravimetric analysis, Differential Scanning Calorimetry and Photo acoustic studies were also carried out to determine the thermal properties of the grown crystal. The dielectric properties for wide range of frequencies (1 Hz to 1 MHz) at different temperatures (35, 40, 60, 80, 100 A degrees C) were analyzed. The second harmonic conversion efficiency of the grown H2SO4 doped urea crystal was found to be 3.75 times higher than the commercially available KDP crystals.