2ND-HARMONIC GENERATION IN INTERLEAVED HEMICYANINE NITROGENCROWN LANGMUIR-BLODGETT MULTILAYERS/

A novel disc-like amphiphilic molecule, with two-chain nitrogencrown w as adopted as a spacer material for fabrication of optical nonlinear L angmuir-Blodgett (LB) multilayers. The intensity of second-harmonic ge neration (SHG) increased quadratically with the bilayer number (up to 116 bilayers) in Y-type hemicyanine/nitrogencrown interleaving LB mult ilayers due to improvement of the structural properties by insertion o f the long hydrophobic tail of hemicyanine molecules between two chain s of nitrogencrown molecules. The second-order susceptibility chi(ZXX) ((2))(-2 omega; omega, omega) = 18 pM V-1 (or 4.35 x 10(-8) esu) was o btained by measuring SHG from the hemicyanine samples.