Optical properties of L-arginine doped potassium dihydrogen phosphate crystals

Potassium dihydrogen phosphate (KDP) exhibits superior nonlinear-optical properties and it has been exploited for variety of applications. Single crystals of organic nonlinear optical material of pure and L-arginine doped potassium dihydrogen phosphate (KDP) were grown by slow evaporation technique from its aqueous solution. The crystal structures of the grown crystals were determined using powder XRD. The powder X-ray diffraction patterns indicated a single phase with the unit cell parameters being unaltered by doping. Infrared and Raman spectroscopies were employed to study the active doping of potassium dihydrogen phosphate crystals with L-arginine amino acid. IR absorption spectra confirmed that the successful doping of L-arginine was achieved by exhibiting the presence of vibrational lines at 1401 cm$^{-1}$, 1637 cm$^{-1}$, 1716 cm$^{-1}$ and 3127 cm$^{-1}$. This affirmation is supported with more evidences from FT-Raman measurements