2ND-HARMONIC GENERATION AND ELECTROOPTIC STUDIES ON LB FILMS OF A NEWBIFUNCTIONAL MATERIAL NMOB

A new amphiphilic compound NMOB [2-nitro-5-(N-methyl-N-decosyl) aminob enzoic acid] with both good film forming property and high optical non linearity was synthesized for applications of Langmuir-Blodgett (LB) f ilms in waveguide-type second harmonic generation (SHG) devices. The n ear-quadratic dependence of the SHG intensity on the bilayer number, t he small angle x-ray diffraction (SAXD) patterns and the temporal stab ility of alternating CdA (cadmium arachidate)/NMOB multilayers confirm ed their good film structures. We obtained the hyperpolarizability bet a of NMOB of 6.3 x 10(-50) C m(3) V-2 (1.7 X 10(-29) esu) at a fundame ntal wavelength of 0.064 mu m from transmitted SHG measurements which agreed with those deduced from our linear electro-optic (EO) modulated attenuated total reflection (ATR) spectra at 832 nm, 633 nm and 488 n m in order of magnitude. A resonant enhancement of the EO response nea r the absorption band in NMOB monolayers was observed for the first ti me.