ஐ.எஸ்.எஸ்.என்: 2471-2698
Zouheir Sekkat
Azo dyes containing materials have been studied intensively over the past decades owing to the ability of the dyes to change shape from an elongated to a more globular form; i.e. ability to isomerize upon light absorption; a photo-reaction which brings about a wealth of applications including switching, and data storage and holography, and gratings, and nonlinear optical effects, and tweezing, and actuation and photomechanics, and micro-nanomachines, and so on. Books and reviews summarize the field. In azo-polymers, photoisomerization of the azo dyes enhances molecular mobility below the polymer’s glass transition temperature (Tg); a phenomenon which is at the origin of photo-assisted poling and surface relief gratings. Photo-enhanced molecular mobility below Tg, with implication of controlling materials mechanical properties, has received considerable interest both from fundamental and applications point of views, and photo-orientation by photoselection is no exception in this regard. Indeed, several research groups studied photo-orientation of azo-dyes by photo-induced birefringence (PIB), for more than three decades, in a number of materials systems, especially azo-polymers, with the aim of understanding and optimizing materials properties for, for example, data storage and polarization holography. I will talk about photoreactive polymers for optics, both from fundamental and applications point of views