Analysis of Wavelength Effect on Birefringence Creation on PAH/PAZO Layer-by-Layer Films

摘要

The influence of wavelength of writing laser beam in the photoinduced birefringence dynamics on layer-by-layer (LBL) films of poly(allylamine hydrochloride) (PAH) and poly {l-(4-(3-carboxy-4-hydroxyphenylazo) benzenesulfonamido)-1,2-ethanediyl, sodium salt} (PAZO) was investigated. Results revealed that the increase of laser wavelength lead to a slower birefringence build up process, whereas the relaxation process stands approximately unchanged. The buildup celerity was shown to follow the film absorbance with wavelength. The imposition of excess energy density to the PAH/PAZO LBL film was also shown to induce morphological changes in the film surface, which are also wavelength dependent.