NONCRYSTALLINE CONDENSATION OF DENSELY DISSOLVED OPTICALLY NONLINEAR ORGANIC-COMPOUND IN POLYMER MATRICES

Optical properties and condensed states of the densely dissolved optic ally nonlinear organic compound in polymer matrices were investigated by means of optical measurements, structural analysis and pressure tun ing spectroscopy. In the investigation of the absorption peak waveleng th, 2-methyl-4-nitroaniline (MNA) in poly(methyl methacrylate) (PMMA) exhibited characteristics intermediate between the crystal and the MNA dissolved in solvents, i.e., noncrystalline condensation. This result was consistent with those of X-ray diffraction analysis, second- and third-harmonics generation, IR absorption and C-13-NMR spectroscopies. It has also been revealed that such a system provides the most suitab le measuring method of the third optical nonlinear constant for a vari ety of compounds.