2ND-HARMONIC GENERATION FROM MIXED-CRYSTALS OF PARA-NITROANILINE WITH SUBSTITUTED BENZENES STUDIED BY THE POWDER METHOD

Second-harmonic generation (SHG) from mixed crystals of p-nitroaniline (p-NA) as guest and various substituted benzenes as host has been measured by the powder method with a 1064 nm YAG laser source. The SH intensities, which varied with crystallization conditions as well as host and mixing ratio, were as high as 100-189 x urea with p-dihydroxybenzene or p-dicyanobenzene as host. The SH intensity tends to increase with the size of the powdered crystals, implying a phase-matchable feature. The SHG activities were stable only at low (5-degrees-C) temperature. It is speculated that epitaxial growth of p-NA crystals on the surface of host crystals would lead to an SHG-activity morphology.