Linear and nonlinear optical characterization of methyl-p-hydroxybenzoate (p-MHB) single crystal grown by TSSG method

The nonlinear optical single crystal methyl-p-hydroxybenzoate (p-MHB) was grown by employing top seeded solution growth method (TSSG) for the first time. A good quality small size crystal grown from methanol solution was inserted into the melt as a seed for growth after seasoning it around the melt temperature. Highly transparent optical quality p-MHB single crystal with regular faceting was harvested after the successful growth run. The unit cell parameter of the grown crystal was determined by powder X-ray diffraction (PXRD) and the crystal structure was confirmed by single crystal X-ray diffraction (SCXRD) methods. The UV-Vis-NIR absorption spectrum has been recorded in the range 200-2700 nm and it shows that the lower cutoff wavelength exits at 307 nm. The study indicates that the grown crystal has good optical transparency window in the visible and near IR region in the range 307-2136 nm. Second harmonic generation (SHG) efficiency of the grown crystal was studied by Kurtz-Perry powder method with 1064 nm Nd: YAG laser beam as a fundamental source and it was about twice that the standard KDP.