OPTICAL 2ND-HARMONIC GENERATION IN ALTERNATELY ASSEMBLED DYE-POLYION MULTILAYERS

Layer-by-layer alternate adsorption of an SHG-active dye (Erichrome Bl ack T: BT) and polycation (poly(diallyldimethylammonium chloride): PDD A) was successfully applied to the construction of an ultrathin NLO fi lm. Quartz crystal microbalance and absorption spectral measurements r evealed satisfactory film growth of BT and PDDA. The optical second ha rmonic signal increased with the number of PDDA/BT bilayers up to five , indicating anisotropically ordered alignment of BT molecules in the assembly.