GROWTH, SPECTRAL, MECHANICAL AND NONLINEAR OPTICAL CHARACTERIZATION OF POTASSIUM HYDROGEN PHTHALATE CRYSTALS

Single crystals of Potassium Hydrogen Phthalate (KHP) have been grown from aqueous solution by slow evaporation technique at 37°C. The carbon and hydrogen environment in molecular design of KHP is determined bythe FT-NMR method. The mechanical strength of KHP was investigated by Vickers microhardness test. The relative SHG efficiency of KHP was measured by employing Kurtz and Perry powder technique using a Q-switched mode-lockedNd:YAG laser emitting 1064 nm. The intensity of the green emission was found to be 1.12 times greater than KDP of KHP crystal.Third-order nonlinear optical properties were determined by the Zscanprocedureby He-Ne laser. Closed aperture Z-scan study reveals the positive nonlinearity in KHP and open aperture Z-scan demonstrates the nonlinear absorption is reverse saturation absorption.