Abstract

Some degree of supramolecular organization can be induced in amorphous polymers containing azobenzene groups by means of polarized light. This phenomenon has been known for about a decade and the relevant literature has been reviewed in one of our recent publications¹. This induced preferred orientation of the azobenzene groups can be monitored by a significant change in the refractive index of the polymer film and can thus be usea as an information storage mechanism. Circularly polarized light restores the natural disorder of the azobenzene orientations, enabling erasure of the stored information^1-5. This phenomenon was first noticed on polymers doped with substituted azobenzenes and was intensively studied on liquid crystalline polymers containing substituted azobenzenes as the mesogenic group. Probably by chance - due to the availability of various azo dyes and to the ease of synthesis - almost all examples previously studied in the literature had electron-donor and electron-acceptor substituents on the azobenzene groups. Their presence conferred another important dimension to this type of supramolecular organization: starting with a polarizable group one could induce second order nonlinear susceptibility in the material, thus opening the possibility of applications in photonics.

© 1993 Optical Society of America