Molecular Crystals and Liquid Crystals · 1993 · 17 citations · 0 references
EngineeringChemistryAzobenzene DerivativesOptical PropertiesPhotopolymer NetworkPolymeric Thin FilmsPhotophysical PropertyPolymer ChemistryMaterials SciencePhotochemistryNon-linear OpticOrganic SemiconductorSupramolecular PhotochemistryPhotochromismPolymer ScienceApplied PhysicsDisperse Red OneSecond Harmonic GenerationConjugated PolymerVisible IrradiationThin FilmsOptoelectronics
Under visible irradiation with polarized light, polymethylmethacrylate (PMMA) films doped or functionalized with Disperse Red One (DR1) exhibit dichroism and birefringence. Both effects are due to the reversible trans-cis photoisomerization. This reaction is also responsible for the photoinduced decrease of the second harmonic generation (SHG) signal measured on these materials previously oriented by Corona poling above the T g of the polymer. This decrease is totally irreversible in the functionalized polymer whereas partly reversible in the doped one, and its intensity is strongly polarization sensitive. The irreversible component can be interpreted as the effect of disorientation and the reversible one (in the doped polymer) as a pure effect of the photochemical reaction