Optical linear anisotropy in hemicyanine Langmuir-Blodgett multilayers

Polarized UV-visible absorption spectroscopy was used to investigate the in-plane orientation of the hemicyanine molecules in Y-type Langmuir-Blodgett multilayers. We demonstrated for the first time that the dipping-induced molecular alignment was enhanced with increasing the layer number due to the interlayer interactions. Polarized UV nanosecond pulses could be used to control the photo-induced reorientation of the hemicyanine molecules. The thermal-isotropic process was accompanied by dissociation of the H-aggregate in the hemicyanine LB multilayers.