Optical storage and surface-relief gratings in azobenzene-containing nanostructured films

This paper brings an overview of photoisomerization-derived properties in azobenzene-containing nanostructured films produced with the Langmuir–Blodgett (LB) and layer-by-layer (LbL) methods. Emphasis was placed on the optical storage and formation of surface-relief gratings (SRGs), where the distinctive properties of the nanostructured films were highlighted. For optical storage, in particular, a discussion was made of the higher birefringence induced in LB films from azopolymers due to their organized nature, and of the strong effects from ionic interactions on the photoisomerization of azochromophores in LbL films. The molecular-level control of film properties in the LbL films is described as being responsible for the varied behavior observed in the photoinscription of SRGs, which may involve considerable level of photodegradation depending on the film fabrication conditions and materials used.