Reversible Photoalignment of Liquid Crystals: a Path toward the Creation of Rewritable Lenses.

In this work, we describe a new reversible photoalignment effect for the director in nematic liquid crystals that provides an approach for the creation of lenses whose optical power can be recorded and erased. The possibility of creating a rewritable lens has very important practical implications, for example, in the ophthalmic lens industry. A rewritable ophthalmic lens could be a convenient solution for patients whose compensation needs change over time due to age-related physiological changes, such as the onset and progression of presbyopia. Using rewritable lenses, small lens power corrections could be implemented through a rewriting procedure on the mounted lens without resurfacing or manufacturing and mounting a new lens. More generally, this new effect multiple potential applications in the creation of rewritable optical systems, such as reconfigurable optical networks, index-tunable antireflective coatings and optically rewritable phase gratings.