Short Communication
Zouheir Sekkat
Abstract
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