Two-photon-induced isomerization and memory effect in functionalized polymers

Functionalized polymers with non-centrosymmetric groups of the diazo-dye type are good candidates as 3-D optical memory materials. The two-photon absorption features relevant to molecular non-centrosymmetry are discussed. A four-wave mixing experiment performed in functionalized polymers reveals the possibility of inducing a permanent grating via two-photon absorption. The effect is used for the storage of a permanent non-centrosymmetry grating.