Dichroism Induced by Photoisomerization of Aniline Tetramers in Polymeric Films

Optically induced dichroism is observed here for aniline tetramers dispersed in polycarbonate films. This effect is attributed to molecular reorientation of the tetramers upon photoisomerization. It is shown that the reorientation process saturates with light intensity and its time evolution is biexponential. However, the optical data storage capability of this system is limited by the small amount of anisotropy conserved after relaxation. Improvement is believed to be possible by attaching the aniline tetramer as a side chain to the polymer backbone.